DSTAHORIZONS
2015
71 Science Park DriveSingapore 118253
www.dsta.gov.sg
DS
TA
HO
RIZ
ON
S 2015
DSTA HorizonsIssue 10ISSN 2339-529X (print) ISSN 2339-5303 (online)©2015 Defence Science and Technology Agency
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DSTA HORIZONS EDITORIAL TEAM
EditorTan Yang How
MembersCher Sok Kheng PatriciaChiam DasenChiam Pack LuanChua Siew Ting PearlyFan Yue SangHeng Eu Chang LeonardHeng Tze Hua AndyHo Kwee Peng JuliLee Kian KongLee Kwee EngLeow Aik Siang
Readers can access current and past issues of DSTA Horizons atwww.dsta.gov.sg/dstahorizons
We welcome your feedback. Please send all correspondence to:
DSTA Horizons Editorial TeamDSTA Academy 1 Depot RoadSingapore 109679
Email: [email protected]
Loo Jang WeiNg Kok KengTan Beng HockTan Chee Hwai DennisTan Kok PengTeo Chong LaiTeo Seow KhyeTeo Siow HiangWang Yew KwangWong Lock LiangZee Sow Wai
Technical EditorProfessor Bernard TanDepartment of Physics, Faculty of ScienceNational University of Singapore
DSTA HORIZONS | 2015
CONTENTS2 Editorial
4 TransformingRangePracticeswiththeMulti-MissionRangeComplex LIMPeter,YEOQiuLingTammi,LIMMengKeeJohnson,LAUChinSengEric
14 InnovativeApproachesfortheAdvancedCombatManSystem LIMWeiQiang,PEHHanYongLester
22 TechnologicalAdvancementsandInnovationsinCombat EngineeringEquipment PHUAZhengqiDaryl,TANChun,WONGYeeYinKimberly
30 DeliveringNewMineCountermeasureCapabilitiestotheRSN GOHYongHan,LAMSuYingAudrey
38 eWorkplace:EvolvingDSTA’sKnowledgeManagementJourney KOOYihLiangKevin,LIMLayHarEvon,HOWeiLingAngela,SOHYunLinJason
46 Model-DrivenArchitectureApproachforEnterpriseSystems LAIKokKee,NGWendy,LOWKweeBoon
54 DataAnalyticsforOptimisingCyberandDataCentreOperations CHANGXuquanStanley,SIMSzeLiang,WONGMingQian
60 ChallengesandDesignConsiderationsforRadarOperation inLocalLittoral LOManLing,LOKEMunKwong
70 KaBandSatelliteCommunicationsDesignAnalysisandOptimisation LEONGSeeChuan,SUNRu-Tian,YIPPengHon
80 PerformanceChallengesforHighResolutionImagingSensors forSurveillanceinTropicalEnvironment LEECheowGim,EEKokTiong,HENGYinghuiElizabeth
90 SafetyManagementofNationalDayParadeFireworksDisplay SIMGimYoung,LEEChungKiat,OEISuCheok,ME5ONGWoeiLeng
100 ProtectionandResiliencyforSingapore’sCriticalInfrastructures ONGKweeSiangSteve,CHONGOiYinKaren,SEEThongHwee
2 DSTA HORIZONS | 2015
EDITORIAL
ThisyearmarksSingapore’sfiftiethyearof independence
and coincidentally, DSTA’s fifteenth anniversary and the
tenthissueofDSTAHorizons.Hence,itisonlyfittingthat
the 12 articles chosen for this issue reflect the diverse
competencies, innovations and expertise of DSTA which
havecontributedtowardsbuildingamodernarmedforces
thatishighlycapableandresourceefficient.
‘TransformingRangePracticeswith theMulti-MissionRange Complex’ traces the innovative development of
the Multi-Mission Range Complex (MMRC), an indoor
live-firing training facility that represents the next step
forwardinmarksmanshiptraining.Bearinguniquefeatures
such as the single-rail targetry system, the MMRC is a
prime example of how creative solutions can overcome
resource and space constraints. Innovative ideas are
also crucial as rapid advancements in technology have
changedthebattlefieldlandscapeandhowtheSingapore
Armed Forces (SAF) operates in the field. ‘InnovativeApproaches for the Advanced Combat Man System’chronicles the enhancements of the Advanced Combat
ManSystem(ACMS)intoitsnewerandlightweightvariant–
theACMSiLITE.Thelessonslearntduringitsdevelopment
serve to highlight possible concepts and technologies
to enhance the SAF’s combat capabilities. Focusing on
key areas of combat engineering tasks on the battlefield
today,‘TechnologicalAdvancementsandInnovationsinCombatEngineeringEquipment’ explores theevolution
ofcombatengineeringequipmentandhowithasshaped
the operational capabilities of the SAF. The article also
looksatfuturetechnologicaltrendsthatwillpossiblyshape
thedevelopmentoffuturecombatengineeringequipment.
DSTA utilises its pool of knowledge to deliver new and
exciting capabilities to the SAF. ‘Delivering New MineCountermeasureCapabilitiestotheRSN’offersinsightsinto the modernisation programme of the Navy’s Mine
CountermeasureVesselswhichimprovestheirminehunting
capabilities. It discusses the technical challenges of the
programmeand theprojectmanagement team’ssystems
engineeringbasedapproach that resulted ina significant
improvementinmissioneffectiveness.
Deriving technical lessons and insights from practical
experiencesisalsoavaluablecomponentofDSTA’swork.
Capturing the key features and design considerations
behind DSTA’s next-generation digital workplace is
‘eWorkplace:EvolvingDSTA’sKnowledgeManagementJourney’.ItdetailsthetransformationofDSTA’seWorkplace
Intranet platform that greatly enhances collaboration,
learningandproductivitywithin theorganisation. ‘Model-drivenArchitectureApproach for EnterpriseSystems’illustrates the features of a Model-driven Architecture
approachandhowitcanimprovetheefficiencyofenterprise
application development. It also shares the architecting
TanYangHowPresidentDSTAAcademy
3DSTA HORIZONS | 2015
effortsandbenefitsofadoptingsuchanapproachaspart
of the IT Application Lifecycle Management framework.
‘DataAnalytics forOptimisingCyberandDataCentreOperations’examineshowDSTAisutilisingdataanalytics
toovercometheincreasinglychallengingtaskofmanaging
cyberdefenceanddatacentreoperationsthroughanomaly
detection, discovery of hidden patterns and insights
and the optimisation of resources. It also explores other
challengesthathavetobeaddressedinordertomaximise
thepotentialapplicationofdataanalytics.
New ideas and perspectives are often triggered in the
face of technical challenges. ‘Challenges and DesignConsiderations for Radar Operation in Local Littoral’describes the challenges posed by Singapore’s unique
littoralenvironmenttoradardesign.Itsauthorsalsoshare
some of their best practices in the operationalisation of
radarsanddiscusspotentialdevelopmentsinthedomain.
‘Ka Band Satellite Communications Design AnalysisandOptimisation’examinesthefeasibilityandapplication
ofaKabandnetworkinsatellitecommunicationsbytaking
a systems approach and carrying out detailed trade-off
analysis of key operational parameters. ‘PerformanceChallenges for High Resolution Imaging Sensors forSurveillance in Tropical Environment’ delves into thescience behind environmental factors such as weather
andhazethatcanadverselyaffectasensor’sperformance
and looks at how the right kind of electro-optics can be
exploitedtoenhancesurveillanceperformance.
Drawing from its experiences in the areas of safety and
security, DSTA has been contributing its expertise in
fireworkssafetymanagementfortheNationalDayParade
(NDP). ‘Safety Management of National Day ParadeFireworks Display’ outlines how safety is addressedthrough the fireworks life cycle and also shares the
innovativesolutionsusedinthereal-timemanagementof
fireworks to deliver a safe fireworks display for theNDP.
Finally, ‘Protection and Resiliency for Singapore’sCritical Infrastructures’ leverages DSTA’s know-how indesigningcriticalinfrastructuresfortheMinistryofDefence
and the SAF to illustrate how protection and resiliency
can be balanced to improve the survivability of critical
infrastructuresinSingapore.
Wehopethatthearticleswillbeaninsightfulandenriching
read for our readers. We are also appreciative of the
authorsandreviewersforalltheireffortsandcommitment.
ThistenthissueofDSTAHorizonsrepresentsasignificant
milestoneinoureffortstoenrichthelearningandsharing
culture within the defence technology community. It is
henceourwishthatDSTAHorizonswillcontinuetoplaythis
importantroleformanymoreissuestocome.Thankyou.
4 DSTA HORIZONS | 2015
TRANSFoRMINgRANgEPRACTICESWITHTHEMuLTI-MISSIoNRANgECoMPLExLIMPeter,YEOQiuLingTammi,LIMMengKeeJohnson,LAUChinSengEric
INTRODUCTION
Supported by efficient services to enable soldiers to fully
focusonshooting,theMulti-MissionRangeComplex(MMRC)
was conceptualised as a one-stop marksmanship training
hub for soldiers to hone and sustain varied marksmanship
competencies.
The three-storey MMRC features seven live-firing indoor
rangesencompassingadvancedsimulation,acousticsensing
and range technologies to provide realistic scenario-based
live-firingtraining.Iteliminatesthetraditionalprocessofrange
administration by outsourcing routine, non-core pre-range
and post-range administration, logistical and maintenance
functions.
TheMMRCisanaccumulationoftherequirementsofmultiple
shootingrangesintoonefacility.Ithasenhancedthewaythe
SingaporeArmytrainsbyprovidingitwiththeflexibilitytotrain
safelyunderdifferentrealisticscenariosandenvironments. It
hasalsoincreasedtheproductivityandefficiencyoftheArmy
by allowing it to conduct 50% more training opportunities
withinthesametimeframe.
OVERVIEW OF LIVE-FIRING SYSTEMS other than conventional targetry systems (e.g. the Portable
ElectronicTargetrySystemandStationaryElectronicTargetry
System)whicharedeployedinotheroutdoorranges,thelive-
firing systems in the MMRC consist of two new modules:
theVideoTargetrySystem (VTS)and theSingle-RailMoving
ElectronicTargetrySystem(METS).
VideoTargetrySystem
The VTS is a leading-edge computer-based marksmanship,
tacticalandjudgementallive-firingtargetrysystemcomprising
threemainsimulationsubsystems:aVTSboxtargetmeasuring
2m by 2.7m, a RangeControl Computer and a Firing Point
Computer.
TheVTSallowssoldierstotrainbeyondthebasicmarksmanship
settingsprovidedbytraditionalbaffledranges.usingcomputer
generated imageryorcustomisedvideos, itcangeneratean
ABSTRACT
TheMulti-MissionRangeComplex (MMRC) is a three-storey live-firing training hub jointly developedbyDSTAand theHeadquarters9thDivision/Infantryof theSingaporeArmy.TheMMRChasbeencited inmanydomainsasanexcellentexampleofhowSingaporeovercamethechallengesofresourceandspaceconstraintswithinnovativesolutions1.
Thisarticleoutlinestheevolutionofmarksmanshiptrainingfromtraditionalandmanuallyoperatedtargetsinanopenfieldtoadvancedandsafelive-firingtrainingsolutionsinanindoorenvironment.ItalsohighlightsthebenefitsoftheMMRC.
Keywords:indoorlive-firing,judgementalshooting,multi-tiershooting,reconfigurableurbanoperationrange,landsaving
5DSTA HORIZONS | 2015
assortmentofconditions realistically (seeFigure1).With the
VTS,soldiersareabletoconductlongdistancemarksmanship
trainingofupto1,000mina50mrangesetup(seeFigure2).
Figure1.Live-firingattheVTSscreen
Figure4.ThebackofaVTSboxtarget
Figure2.VTSscreenssetupinthe50mrange
Figure5.Anacousticsensor
The VTS’ shot detection system utilises precision acoustic
technology toprojectbullet trajectoriesbasedon the actual
ballistictableswithinmillimetreaccuracy(seeFigure3).
Figure3.Anexampleofaballistictable
0 1000 2000 3000 4000 5000 6000 7000
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
Range (m)
Height (m
)
70o
60o
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10o
The VTS box target resembles a box with a rubber screen
installed at the front and at the back which allows bullets
to pass through (see Figure 4). The construction of the box
contains the shockwaves (generated by the bullet passing
through) within the box to minimise noise. Twelve acoustic
sensorsareinstalledwithintheboxtodetectthesesupersonic
shockwaves(seeFigure5).
6 DSTA HORIZONS | 2015
Theactuallocationofthebulletimpactisthendeterminedby
monitoringtheshockwavesviatheacousticsensorsoptimally
locatedattheedgesofthescreen(seeFigure6).Thelocation
ofthebulletwouldthenbecalculatedbyextrapolation.
However, subsonic ammunition such as the 9mm round is
designedtooperateatspeedslessthanthespeedofsound
andwill not create supersonic shockwave as it travels. The
detection is instead computed when the projectile hits the
rubberscreenlikeadrum.
Basedonmathematicalmodelsand theactualbullet impact
Figure6.Coordinatesofshot(x,y)determinedbyextrapolationofshockwaves/sounddetectedbythesensors
RESTRICTED
y
Acoustic sensors located within the box
x (0, 0)
𝑥𝑥𝑎𝑎, 𝑦𝑦𝑎𝑎 , 𝑡𝑡𝑎𝑎
Figure7.Simulatingtrajectoryofabulletbeyondthephysicaldistance
𝑑𝑑 = 𝑣𝑣2 sin 2𝜃𝜃 𝑔𝑔 , 𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑓𝑔𝑔 𝑜𝑜𝑓𝑓 𝑎𝑎 𝑓𝑓𝑓𝑓𝑎𝑎𝑓𝑓 𝑔𝑔𝑓𝑓𝑜𝑜𝑔𝑔𝑓𝑓𝑑𝑑
Simulated Trajectory Actual Trajectory
Range (ft)
Heig
ht (f
t)
pointonthescreen,thetrajectoryofthebulletisthencalculated
andsimulated fordistancesbeyondthephysicaldistanceof
thescreen(seeFigure7).
7DSTA HORIZONS | 2015
MovingElectronicTargetrySystem
Themulti-tierrangeattheMMRCfeaturesasingle-railMETS
co-inventedbyDSTA(seeFigure8).Thenewsingle-railMETS
eliminatesanypotentialline-of-sightissuesfortraineeslocated
onlowerlevelsfiringathigher-leveltargets.unlikeconventional
movingtargetrysystemsasshowninFigure9,thenewdesign
requires a shorter installation depth (0.96m instead of 2.4m)
andutilisesonlyonemotor todrive thesingle railof targets.
Hence,forarangewith10firinglanes,thisnewdesignsaves
anaverageofabout70m2perrange.
MAINTAINING HIGH SAFETY STANDARDS
AsthisistheSingaporeArmedForces’(SAF)firstindoormulti-
storey live-firing facilityof thisscale,maintaininghighsafety
standardsforfirers,facilitypersonnelandthefacilityitselfisof
thetoppriority.AllrangesintheMMRCarefittedwithrobust
ballisticprotectionsystemsthatweresubjectedtostrictand
rigorousvalidationpriortoinstallation,tomitigatethehazards
associatedwithfiringinanindoorrange.
OverallRoundContainment
TheMMRCisdesignedforfullroundcontainmentandhence
there is noneed to cater for aweapondanger areaoutside
the range. In order to ensure total round containment, steel
escalatorbullettrapsandgranularrubberbulletcatchersare
installedinthe50mand100mrangestocontaintheammunition
allowed intherangesfromdesignatedfiringpoints.Portable
hard traps that are constructed from armoured steel are
overlaidwithshreddedrubberpanelmountedonspacerbars
andareusedasbullettrapsintheurbanoperationsRange.
Inaddition,allrangeshavewalls(inclusiveofcolumns),floors
andceilingsthataremadeofreinforcedconcretedesignedin
compliance with requirements stipulated in the JSP403 uK
range safety handbookand verified tobeable to effectively
containtheroundsfiredintheMMRC.
Hazardous Ricochet and Backsplash Hazards
Ballisticprotectionsystemsareinstalledtopreventhazardous
ricochets and backsplash associated with firing in indoor
ranges. They also serve as additional protection to prevent
roundescapementandprotecttheranges’concretewallsand
ceilingsfromoccasionalshots.
Shreddedrubberpanel(SRP)isusedextensivelyintheranges
to prevent hazardous ricochet and backsplash hazards to
the firers.Majority of theSRParemountedon spacerbars,
whichinturnareweldedtoarmouredsteelplate.Thissystem
isusedfortherangewalls,ceilingbaffles,targetmechanism
protection system and floor baffles to prevent ricochet and
backsplash hazards to the firers (see Figure 10). Bullets
thatpass through theSRPand strike the steelwouldeither
fragmentordeform,andthedensityoftheSRPpreventsany
fragmentsordeformedprojectilesfrompassingbackthrough
intotherangearea.
Restricted
Bottom Tier
Top Tier
UNEQUAL LINE OF SIGHT
Restricted
Bottom Tier
Top Tier
UNEQUAL LINE OF SIGHT
Figure8.Single-railMETS Figure9.ConventionalMETS
Restricted
UNEQUAL LINE OF SIGHT
Restricted
UNEQUAL LINE OF SIGHT
TRANSFoRMINgRANgEPRACTICESWITHTHEMuLTI-MISSIoNRANgECoMPLEx
8 DSTA HORIZONS | 2015
Redirectiveguardsarepositionedimmediatelyinfrontofand
abovethethroatofthebulletcatchers(seeFigure11).Inmost
cases,theredirectiveguardswillbewithintheweapondanger
area and therefore require thicker armoured steel plate. The
guards are hung at an angle to ensure that projectiles are
directedintothethroatofthebulletcatcherandwillcontinue
theirtravelintothedecelerationchamberofthebulletcatcher.
Inaddition,theangleatwhichtheplatesarehungwouldalso
ensure that the pitting on the steel plates would not cause
hazardousricochetandfragments,andinjurethefirers.
Figure10.Ceilingbafflesin50mRange1and2
Figure11.Redirectiveguardsusedatthebullettraps
Protection of Personnel in Control Room and Learning Gallery
Ballistic glass is installed in the control room and learning
gallerytoallowtrainersandsoldierstoobservethelive-firing
activitiessafely(seeFigure12).Theballisticglassisratedto
beabletowithstand7.62mmx51mmNATorounds,andits
performancewasverifiedduringcomponenttesting.
9DSTA HORIZONS | 2015
EnsuringSafetyduringFireandMovement
Toensurethesafetyofsoldiersduringlive-firetacticaltraining
involving the firing of small arms, a safety angle is applied
betweenthesideofthefiringpointandthenearestfireronthe
adjacent lane.This safetyanglecomprisesa ricochet safety
angleplustheappropriateconeoffireangle.
Forfireandmovementtraining2,itwasdeterminedthatawider
firinglanewasrequiredforeachfirer.Insteadofhaving10firing
lanesforstaticfiring,therangehadtobereconfiguredtohave
just seven firing lanes. To comply with the requirement, the
teamsuccessfully redesignedthe range toallowthe10-lane
range tobeeasily reconfigured intoaseven-lane range (see
Figure13).Thiswasachievedbymountingthestaticelectronic
targetsonmovablerailswhichallowthetargetstobemoved
manuallyandlockedintoposition.
Figure12.Ballisticglassinstalledatthecontrolroomandlearninggallery
Figure13.Comparisonbetweena10-laneandseven-lanerange
TRANSFoRMINgRANgEPRACTICESWITHTHEMuLTI-MISSIoNRANgECoMPLEx
10 DSTA HORIZONS | 2015
EnvironmentalSafety
The ranges in the MMRC are ventilated mechanically. The
designoftherangeventilationsystemiscrucialinminimising
the accumulation of contaminants in the range as well as
in preventing contaminants from flowing into the adjacent
spaces. This reduces the risk of contaminants inhalation by
soldiersandinstructors.
The range ventilation system is designed to create a low-
velocity,uni-directionalairflowtowardsthetargetryareawhere
anexhaustsystemfiltersthecontaminantsbeforedischarging
theairintotheexternalenvironment(seeFigure14).Forsuch
acomplextask,numericalmodellingusingComputationFluid
Dynamics (CFD)wasused indesigning the rangeventilation
system for the first time inSingapore (seeFigure15).Areas
of stagnation and high air velocity were identified and the
designwasrefinedoverseveraliterationstoimproveairflow.
Topreventtheoutflowofcontaminantstotheadjacentspaces,
theairpressureintherangeismaintainedataslightly lower
pressure than the surrounding spaces. Differential pressure
sensors are installed to measure the pressure differential
between the range and its adjacent spaces. The Building
AutomationSystemmonitors these sensors in real timeand
regulates the speed of the exhaust system to maintain a
differentialpressureof5Pato15Pabetweentherangeandthe
adjacentarea.
Figure14.Schematicofrangeventilationsystem
Figure15.CFDmodellingofairflowvelocityintherange
11DSTA HORIZONS | 2015
BENEFITS OF THE MMRC
The operationalisation of the MMRC has brought about many
benefits to the SAF and commercial entities.
Optimising Allocation of Resources
To ensure training hours are optimally utilised, a soldier-centric
workflow was created to enhance the positive experience
of soldiers from registration to exit. All routine, non-core
administrative tasks were streamlined and outsourced to
a commercial entity, allowing the SAF to focus on core
competency development. Conversely, the commercial entity
is able to leverage its creativity and experience to manage
its operation and staffing efficiencies to meet contractual
performance requirements. Unlike traditional outdoor ranges,
training is not subjected to external weather and lighting
conditions in the MMRC. In particular, soldiers do not need
to cease training due to a downpour or wait long hours after
their daytime training for nightfall before proceeding with their
nighttime training. Hence, the waiting time and time needed
for administration and logistics matters have been efficiently
converted into training time for soldiers.
Aligned Vision in National Development
Some of the existing outdoor live-firing ranges in Singapore
are sited on valuable state land that have to be returned to
the Singapore Land Authority (SLA) progressively for land
redevelopment. The DSTA Integrated Project Management
Team performed detailed studies and planned strategically for
the land required to build the MMRC and reduced the total
footprint for constructing seven typical outdoor ranges by at
least 3.7 times. This approach also enabled the Ministry of
Defence (MINDEF) and the SAF to achieve total land savings of
22 hectares, equivalent to 30 football fields. With the delivery
of the MMRC, the land occupied by existing outdoor firing
ranges can be returned to SLA progressively. The MMRC also
minimises the need to develop new conventional ranges.
CONCLUSION
The MMRC has become a critical training facility of the Army
and provides a pleasant experience for our current generation
of national servicemen. It has also paved the way for future
training infrastructure and systems development. It is at
the forefront of training development and has crossed new
boundaries, creating a paradigm shift in the way the SAF
conducts its live-firing training. The capabilities delivered by
the MMRC have provided the SAF with a safe yet challenging
environment to train and sustain instinctive and judgemental
shooting competencies, and instils a positive experience in
every soldier that trains in the facility.
ACKNOWLEDGEMENTS
The authors would like to thank the late Deputy Director
(Operations and Support - Army) Mr Ng Tiong Lee for his
guidance and for forming this team. The authors would also
like to acknowledge the guidance and ideas from the senior
management of DSTA, MINDEF and the SAF, as well as
colleagues who have contributed to the successful delivery of
the MMRC.
ENDNOTES
1 The MMRC was awarded the IES Prestigious Engineering
Achievement Award (2014), Defence Technology Prize Team
(Engineering) Award, MINDEF Innovation Project and Savings
And Value Enhancement (SAVE) Awards in 2013.
2 Fire and movement training is a shooting drill that requires
soldiers to take cover, take aim, fire and move forward to
another location to repeat the drill.
TRANSFORMINg RANgE PRACTICES WITH THE MULTI-MISSION RANgE COMPLEx
12 DSTA HORIZONS | 2015
BIOGRAPHY
LIM Peter is a Programme Manager
(NetworkedSystems)wholedinthedelivery
of the Multi-Mission Range Complex
(MMRC).PetergraduatedwithaBachelorof
Technology(ElectronicsEngineering)degree
and a Master of Engineering (Electrical
and Computing) degree from the National
university of Singapore (NuS) in 2001
and2005 respectively.He furtherobtainedaMasterofScience
(Software Engineering) degree from the Naval Postgraduate
School,uSA,in2011.
YEOQiuLingTammisupportedthedelivery
of targetry and simulation systems in the
MMRC when she was a Project Manager
(Networked Systems). She is currently
pursuing a Master of Science (operations
Research)degreeattheNavalPostgraduate
School, uSA. Tammi graduated with
a Bachelor of Engineering (Electrical
Engineering)degreeandaMasterofScience(IndustrialSystems
Engineering)degreefromNuSin2006and2012respectively.
LIM Meng Kee Johnson is a Manager
(Buildingand Infrastructure). Hehasmore
than 15 years of experience in designing
and commissioning air-conditioning,
ventilation and fire protection systems for
military facilities. Johnson graduated with
a Bachelor of Engineering (Mechanical
Engineering)degree fromNanyangTechnologicaluniversityand
aMasterofScience(IndustrialandSystemsEngineering)degree
fromNuS in1996and2008 respectively.He furtherobtaineda
MasterofScience (FireProtectionEngineering)degree from the
universityofMaryland,CollegePark,uSA,in2010.
LAU Chin Seng Eric was a System
Manager (Systems Management). As the
range safety engineer for the MMRC, he
provided technical assessmentandadvice
inensuringthatthedesignoftherangesin
MMRCcompliedwithexistingrangesafety
guidelines.Erichas representedSingapore
in the annual International Range Safety
Advisorygroupmeetingwhichcomprisesexpertsandpractitioners
inrange.HegraduatedwithaBachelorofEngineering(Chemical
Engineering)degreefromNuSin2006.
13DSTA HORIZONS | 2015
TRANSFoRMINgRANgEPRACTICESWITHTHEMuLTI-MISSIoNRANgECoMPLEx
14 DSTA HORIZONS | 2015
INNoVATIVEAPPRoACHESFoRTHEADVANCEDCoMBATMANSySTEM
INTRODUCTION
LIMWeiQiang,PEHHanYongLester
ABSTRACT
TheSingaporeArmywasequippedwiththeAdvancedCombatManSystem(ACMS)in2010toenhancethesurvivabilityandcombatcapabilityofsoldiersinurbanoperations.WhiletheACMSachieveditsobjectives,theProjectManagementTeam(PMT) identifiedareasfor improvementwhichresultedina lightersystemandanenhanceduser interfaceutilisingmulti-touchtechnologysimilartocommercialelectronicdevicessuchassmartphones.
ThisarticlecapturesthejourneytakentodevelopanddesignanewerandlightweightvariantoftheACMS–theACMSiLITE, using a soldier-centric approach. The article also shares lessons learnt from this process, and introduces someconceptsand futuristic technologies that thePMT isexploring toenhance thefightingcapabilitiesof thesoldier in theSingaporeArmedForces.
Keywords:urbanoperations,ACMS,CoTS,smartphone,soldier-centric
With the prevalence of global urbanisation, the Singapore
Armywill inevitablyneedtoengageinurbanoperations.The
urban environment presents a whole newmulti-dimensional
battlefield – one which not only requires changes to
conventionalcombatoperationsandtactics,butalsoaneed
toovercomethestrategicadvantageaffordedtoanadversary
thatisconcealedandentrenchedinanurbanenvironment.
The Advanced Combat Man System (ACMS) is an urban
fightingsystemfortheThirdgenerationArmy.Itisdesignedto
addressthechallengesfacedinurbanoperationsbyenhancing
commandandcontrol(C2),situationalawareness,survivability
andlethalityofthesoldier.Inadditiontobeingequippedwith
theACMS, soldiers are equippedwith remote sensors such
as surveillance robotsandkeyhole sensors.With theACMS
andthesesensors,soldiersbecomepartofanetworkedforce.
Soldiers’ situational awareness is thus enhanced, allowing
themtoengagetheirtargetseffectively.Soldiersarealsoable
tonavigateaccurately through theurbanbattlefield toavoid
knowndangerareas.Thekeycomponentsof theACMSare
illustratedinFigure1.
15DSTA HORIZONS | 2015
Figure1.overviewoftheACMS
Figure2.Thenetworkedsoldierandhiscomplementarycapabilities
the lethality and situational awareness of their units (see
Figure 2). The soldiers themselves become sensors on the
ground,providingreal-timeinformationtothecommandersfor
improvedbattlefieldcoordination.
TheACMSalso allows selected appointment holders to tap
the wider resources of the battalion, such as the TERREx
InfantryCarrierVehicle(ICV)forfiresupportandsustenance,
andevenutilisehighercommandresourcestofurtherenhance
1. Personal Radio − Enables soldiers to share
voice and data information with his peers and commanders.
− Contains in-built Global Positioning System (GPS) for positional tracking.
2. Head Mounted Display (HMD) - Allows soldiers to view
location of friendly and hostile forces on digital maps.
3. Portable Computer - Processes and
analyses data from GPS, sensors and other ACMS sets.
4. Communication Keypad - Enables soldiers to
access hot keys such as “Call-For-Medic” and “On-Contact”. Request will be sent to peers and commanders.
5. Weapon Interactor − Allows the soldier to
perform round corner firing without exposing himself.
1
5
2
4
3
1. Personal Radio − Enables soldiers to share
voice and data information with his peers and commanders.
− Contains in-built Global Positioning System (GPS) for positional tracking.
2. Head Mounted Display (HMD) - Allows soldiers to view
location of friendly and hostile forces on digital maps.
3. Portable Computer - Processes and
analyses data from GPS, sensors and other ACMS sets.
4. Communication Keypad - Enables soldiers to
access hot keys such as “Call-For-Medic” and “On-Contact”. Request will be sent to peers and commanders.
5. Weapon Interactor − Allows the soldier to
perform round corner firing without exposing himself.
1
5
2
4
3
1. Personal Radio − Enables soldiers to share
voice and data information with his peers and commanders.
− Contains in-built Global Positioning System (GPS) for positional tracking.
2. Head Mounted Display (HMD) - Allows soldiers to view
location of friendly and hostile forces on digital maps.
3. Portable Computer - Processes and
analyses data from GPS, sensors and other ACMS sets.
4. Communication Keypad - Enables soldiers to
access hot keys such as “Call-For-Medic” and “On-Contact”. Request will be sent to peers and commanders.
5. Weapon Interactor − Allows the soldier to
perform round corner firing without exposing himself.
1
5
2
4
3
1. Personal Radio − Enables soldiers to share
voice and data information with his peers and commanders.
− Contains in-built Global Positioning System (GPS) for positional tracking.
2. Head Mounted Display (HMD) - Allows soldiers to view
location of friendly and hostile forces on digital maps.
3. Portable Computer - Processes and
analyses data from GPS, sensors and other ACMS sets.
4. Communication Keypad - Enables soldiers to
access hot keys such as “Call-For-Medic” and “On-Contact”. Request will be sent to peers and commanders.
5. Weapon Interactor − Allows the soldier to
perform round corner firing without exposing himself.
1
5
2
4
3
16 DSTA HORIZONS | 2015
A FORCE MULIPLIER
Priortothefieldingof theACMS,battlefield informationwas
disseminated verbally. This limited the speed and accuracy
of engaging targets,with soldiers requiring a longer time to
interpret commands, identify targets and engage them. The
ACMS,withitsgraphicalpresentationofbattlefieldinformation,
has enabled soldiers to share up-to-date information in a
preciseandswiftmanner.
TheACMShasalsoconnecteddismounted soldiers to their
TERREx ICV. This has allowed the sharing of a common
operational picture and provision of support fire from the
weaponsystemoftheTERRExICV.
REINVENTING THE ACMS
WhiletheACMSmetitsintendedobjectivesintermsofweight
andcapabilities,andbenchmarkedwellagainstotherleading
soldier modernisation programmes globally, the Project
Management Team (PMT) was cognisant of the need to
continuallyreinventthesystemtoensurerelevancy.oneareaof
interestwasinthefieldofpersonalinfocommtechnology.The
introductionofsmartphonesredefinedthetraditionalconcept
of a phone. Features like emails, messaging, photography,
video,maps,gamesandotherapplicationswerepackedinto
an elegant, lightweight device. A multi-touch user interface
replacedphysicalbuttonsandkeyboards.
Not surprisingly, smartphones were well received by
consumers.Itdidnottakelongfortheconsumermarkettobe
saturatedwithsmartphonesandsimilarlifestyletechnologies.
Thesmartphonesoonbecameapervasivelifestyledevice.
As the smartphones packed tremendous computing power
in a small form factor, the PMT envisaged that the use of
smartphonesintheACMScouldachieveweightreductionand
enhanceusability.
THE BIRTH OF A LIGHTWEIGHT ACMS VARIANT
Inlightoftherapiddevelopmentoflifestyledevices,thePMT
determinedtheneedtodevelopanewversionoftheACMS
that would be more useful and better received by soldiers.
Theopportunityarosewhenfeedback,gatheredthroughtrials
and exercises, indicated that itwas desirable to reduce the
weightoftheACMS.Itwasalsonotedthatthelowerechelons
(section-levelandbelow)didnotrequirethefullsuiteofACMS
capabilitiessincetheywouldbeoccupiedwiththeimmediate
fire fight. Thus, the idea to create a new lightweight variant
oftheACMSwhichwouldonlyhavetheessentialcapabilities
required at the tactical levels, was conceived. This was the
iLITE.
It was envisaged that the iLITE would leverage both the
existing technologies employed for the in-service ACMS as
well as commercial-off-the-shelf (CoTS) technologies. The
iLITEwouldbelighter,simplerandmoreintuitivetousewhile
meeting the required operating duration and conditions. It
wasclearthatmaximisingbatterylifewouldbeakeydesign
consideration as this would reduce the number of batteries
required and consequently the overall system weight. To
make the iLITE simple and intuitive to use, familiar CoTS
smartphoneswouldbeadoptedasthemediumthroughwhich
thesoldier interactswith thesystem.Thesebecamethekey
designconsiderationsfortheiLITE.
DEVELOPMENT OF THE ILITE
QuesttoAdoptCOTSSmartphone
At the outset of the iLITE’s design, the PMT had initiated
the use of a CoTS smartphone as the input, display and
processor of iLITE. However, knowledge of hardening third
partysmartphoneswasstilllacking.Therewerealsoconcerns
about the ability of CoTS devices to comply with military
ruggedisation standards suitable for soldier use. Hence,
thePMTwas facedwith theundesirable optionof adopting
bespoke smartphones with features modelled after CoTS
smartphones.
These concerns did not deter the PMT from their vision of
an iLITE design based on CoTS smartphones. Moreover,
thePMTassessed that thecommercialsector,with itshuge
R&Dfunding,wouldcontinuetospearheadinnovationsinthe
fieldofpersonal infocommtechnology. Inaddition, thehuge
commercialmarketprovidedbetterleverageforaccesstothe
latesttechnologiessuchashigh-speedprocessorsandlonger
batterylife.ThisconvincedthePMTthatabespokesmartphone
wasunlikelytomatchuptotheCoTSsmartphonesthatthe
soldierswereaccustomedto.Itwasalsolikelythatabespoke
smartphonewouldbemadeobsoletebeforelong.
ThePMTovercamethechallengesinvolvedinhardeningCoTS
smartphonesbytappingthewiderexpertisewithinDSTA.At
thesametime,avarietyofCoTSsolutionsforwaterproofing
17DSTA HORIZONS | 2015
and shock protection for the more popular smartphones
was entering the market, potentially addressing the Army’s
ruggedisationneeds.
SelectingSmartphoneforiLITE
ThesearchforasuitableCoTSsmartphoneforiLITEbeganwith
theselectionofasuitablemobileoperatingSystem(oS).The
AndroidoSwaseventuallyselectedoverotheroSsduetoits
abilitytobecustomisedtomeetthePMT’srequirements,and
ithavingthelargestmarketshareatthetimeofdevelopment
whichwouldreducetheriskofhardwareobsolescence.
A study was then conducted on a range of leading CoTS
Androidsmartphonesintheconsumermarket.Itcametothe
PMT’sattentionduring themarket researchthateachphone
manufacturerhadsomethingdifferent toofferandtherewas
nosuchthingasabestsmartphone.
After much deliberation, the PMT decided on a set of key
considerations that would guide the selection of a suitable
smartphone. First, it should have the largest market share
amongtheAndroidsmartphonemakerswhichwouldincrease
theavailabilityofCoTSruggedisedcasings.Second,itshould
possess superior technical performance to provide greater
utility in the iLITE.Third, it shouldhavea screenwhichwas
large enough for viewing while still allowing operation with
one hand. Last of all, it should comewith a power-efficient
screentechnologythatwouldprolongtheoperatingduration.
A smartphone was finally selected based on the above
guidelines.
StrategyforWeightReduction
TheimplementationofaCoTSsmartphonewasacrucialpart
of the PMT’s strategy to reduce system weight. Instead of
incorporatingtwodistinctsubsystems(theportablecomputer
andthecommunicationkeypad)withinthein-serviceACMS,the
iLITEsmartphoneservedastheintegratedmobileprocessor,
inputanddisplaysubsystems.Thisreducedthesystemweight
by more than 50%. The lower power requirements of the
processor1used in theAndroidoSalsomade itpossible to
reducethenumberofbatteriesrequiredfortheiLITE.
There are two key differences between the current ACMS
andtheiLITE.First,theiLITEusesaCoTSsmartphoneasan
integratedmobileprocessor anddisplay subsystem, instead
of a separate soldier computer and head mounted display.
Second, the iLITE requires only one battery for the entire
missionasopposedtothreeintheACMS.Thekeydifferences
areshowninFigure3.
Figure3.KeydifferencesbetweenACMSandiLITE
Current ACMS – Full Suite of Software Features
Communication Keypad
Battery (x3)
HMD
Portable Computer
Navigation System
Smartphone
Battery (x1)
Comms System
Navigation System
iLITE – Essential Software Features
for Tactical Levels
INNoVATIVEAPPRoACHESFoRTHEADVANCEDCoMBATMANSySTEM
18 DSTA HORIZONS | 2015
Although the Army was prepared to trade ruggedness2 of
the smartphones for weight reduction, the PMT remained
steadfast in pursuing CoTS solutions to meet the Army’s
ruggedisationneeds.Atthattime,thecommercialmarketwas
rollingoutavarietyofproductsandsolutionsforwaterproofing
andshockprotectionofpopularCoTSphones.Theseinclude
waterproof phones, ruggedisedprotective casings and even
water-repellentnano-coatings.ThePMT’seffortpaidoffwhen
usertrialsvalidatedthattheCoTSprotectivecasesprovided
adequateruggedisationforthesmartphones.
StrategytoImproveSystemErgonomics
To improve soldier receptivity towards the iLITE, human
factors engineering expertise was engaged to enhance its
ergonomics.Thisincludedwearabilitystudiestodeterminethe
optimalplacementoftheiLITEcomponentsonthesoldier,as
wellasthedesignoftheiLITEC2graphicaluserInterfacefor
greatereaseofuse.Numerous trialswereconductedduring
the development of iLITE as part of an iterative process to
gatheruserfeedbackonthesystemdesign.
A phased equipping approach was also implemented for
the iLITE,where lessons learnt and feedback received from
preceding deliverieswould be incorporated into subsequent
batchdeliveries.
OPPORTUNITIES BROUGHT FORTH BY ILITE
The advent of the smartphone also provided functionalities
beyondtheiLITErequirements.Forinstance,thesmartphone
could be used by soldiers to access e-learning materials
suchasthoseprovidedontheLEARNetplatformattheirown
time.otherusefulutilityapplications thatwerecommercially
available in the Android’s application store (such as the
compassandrangefindingtools)couldalsobemadeavailable
tothesoldier.
onamorecomplexscale,theiLITEcouldbeintegratedwith
other systems such as the Tactical Engagement System3
(TES) to achieve weight and cost savings. Through suitable
applications, the iLITE’s smartphone could also be used
to control unmanned platforms to complement a soldier’s
mission.
LESSONS LEARNT
While CoTS products can be cost-effective solutions, the
fastpaceoftechnologicaladvancementsinCoTSinfocomm
technologies can render these solutions obsolete in two to
three years. A comprehensive obsolescence management
planwould need to be adopted to facilitate the insertion of
newtechnologiesandtacklepotentialhardwareobsolescence
issues:
a) Modular Architecture - System components should be
keptmodular,whereverpossible, to ensure that anupgrade
ormodificationinonesubsystemwouldnothaveasignificant
impactontherestofthesubsystems.
b) Phased Equipping - A phased equipping approach
shouldbeadoptedtoenableincorporationofrefinementsdue
totechnologicalimprovementsanduserfeedback.
c) Software Portability - The C2 software should be
designedforeaseofmodificationandexpansioninanticipation
of future upgrades, such as hardware changes or insertion
of new technologies. For the Android oS in particular, C2
functionalitiesshouldbeimplementedattheapplicationlevel,
whereapplicable, toallow thedevelopedC2software tobe
portedtothelatestfirmwareversionwithminimaleffort.
d) Regular Reviews - The PMT should keep abreast of
technological improvements and development in market
trendsinordertoassesstheevolutionofCoTSsmartdevices
andoS trendsat regularpre-planned reviews. If there is an
anticipatedshift in theoSmarket shareorobsolescenceof
existing hardware that could impact the project severely,
the obsolescence management plan should be updated
accordingly.
FUTURE TECHNOLOGIES
TheintroductionofiLITEhasputtheArmyattheforefrontof
soldier digitisation. It is imperative to stay updated on new
technologiesthatarebeingdevelopedconstantlythroughout
theworld.Thesenewtechnologiesneed tobeharnessedat
appropriate junctures to enhance mission effectiveness for
soldiers. Several emerging technologies that could possibly
seeapplicationintheACMSareasfollows:
a) WearableTechnologies -Thecommercialmarkethasa
varietyofwearabletechnologies,rangingfromsmartwatches
toeyewearsuchasthegoogleglass.Althoughthesewearable
19DSTA HORIZONS | 2015
technologieshaveyettogaintraction,itremainsaninteresting
andexcitingareatomonitor.Figure4highlightssomepotential
applicationsofwearabletechnologies.
b) SimultaneousLocalisationandMapping(SLAM)-SLAM
allowssoldierstoconstructamapofanunfamiliarenvironment
as they are navigating through it. This technologywould be
extremelyusefulwhensoldiersnavigatethroughbuildingsand
internal spaces. This could be achieved by networking the
iLITE to a SLAM-enabled unmanned ground vehicle (ugV).
Thistechnology,whilestillinitsinfancy,wouldfurtherenhance
thecapabilitiesofthenetworkedsoldier.
c) VoiceandGestureRecognitionApplications-Voiceand
gesturerecognitionapplicationswouldenhancetheabilityof
soldierstocontrolsensorsassetssuchasugVs.Inaddition,
voicerecognitionwouldenablesoldierstoperformthedesired
functiononthesmartphonewithouthavingtogothroughthe
processmanually,thusgivingrisetoquickerresponses.
d) WirelessCharging-Wirelesschargingcouldbeexplored
toprovideadditionalchargingoptionsfortheArmy.Potential
applicationsincludewirelesscharginginvehiclesthatenables
the batteries on soldiers to be charged while in vehicles.
Vehiclescouldalsoserveashot-spotsforwirelesscharging,
allowingsoldierstochargetheirdevicesincloseproximityto
thevehicle.
e) Energy Harvesting - As soldiers carry more electronic
gear,thegrowingenergydemandsposeanenormousburden
onthelogisticssupportsystem.Soldierswillalsohavetocope
withtheweightofextrabatteries.Energyharvestingtechniques
could be explored to improve the sustenance of soldiers in
the battlefield. one promising technique is biomechanical
harvesting, inwhichelectricity isgeneratedviabodymotion
suchaswalking.
CONCLUSION
The PMT’s decision to design the iLITE based on a CoTS
smartphonewas forward looking. The iLITE hasmet its key
objectivesofweightreduction, improvedsystemergonomics
andintuitiveness.ThisenhancedACMSvariantimprovesthe
Army’sfightingcapabilitiesgreatlybypackingmorepunchata
lowerweightrequirement.
The successful implementation of CoTS technologies in
iLITEhasproventheviabilityofleveragingCoTSsolutionsfor
operational equipment. Trade-offs were managed to deliver
cost-effective CoTS solutions that not only met the Army’s
requirements, but were also highly adaptive to the dynamic
paceoftechnologicaladvancement.
ACKNOWLEDGEMENTS
TheauthorswouldliketothankMrNgyuenCheongandMs
Ang Chai yit for their guidance and valuable inputs in the
preparationofthisarticle.
Figure4.Potentialapplicationsforwearabletechnologies
1. Eyewear − Augmented reality
technology to enhance soldier’s situational awareness
− Potentially guide soldiers to objectives/targets
3. Smart Watches − Could be paired with
smartphone to alert the user to incoming messages
2. Smart Clothing − Comes with sensors to
keep track of soldier’s health indicators e.g. heart rate, and alert medics when soldier is injured. In-built flexible batteries would power these sensors
− Able to switch camouflaging pattern according to environment
− Sensors to detect the presence of chemical agents in the environment
INNoVATIVEAPPRoACHESFoRTHEADVANCEDCoMBATMANSySTEM
20 DSTA HORIZONS | 2015
ENDNOTES
1 ARMprocessorsareafamilyof32-bitReducedInstruction
SetComputer(RISC)microprocessorsdevelopedbyAdvanced
RISCMachines.
2 SmartphonesareCoTSproductswithdesignsthatcannot
bemodifiedeasily.
3 TES is a laser-based system currently used in combat
trainingexercisestosimulatetheeffectsofweapons.
BIOGRAPHY
LIM Wei Qiang is an Engineer (Land
Systems) involved in identifying and
leveraging technologies to enhance power
managementandloadreductionforsoldiers.
Hewaspartoftheteamthatdevelopedthe
Advanced Combat Man System (ACMS)
and the iLITE. Wei Qiang graduated with
a Bachelor of Engineering (Mechanical
Engineering) degree from Nanyang Technological university in
2010withspecialisationinEnergyandtheEnvironment.
PEHHanYongLesterisaProjectManager
(Land Systems) currently overseeing
the development of the ACMS iLITE. In
particular, he is involved in leveraging
technologies of interest to further enhance
the capabilities of the ACMS iLITE. under
the DSTA undergraduate Scholarship,
Lester obtained a Bachelor of Science in
Engineering (Electrical Engineering) degree from the university
ofMichigan,uSA,aswellasaMasterofScience(Management
ScienceandEngineering)degreefromStanforduniversity,uSA,
in2007and2008respectively.
21DSTA HORIZONS | 2015
INNoVATIVEAPPRoACHESFoRTHEADVANCEDCoMBATMANSySTEM
22 DSTA HORIZONS | 2015
TECHNoLogICALADVANCEMENTSANDINNoVATIoNSINCoMBATENgINEERINgEQuIPMENT
INTRODUCTION
Combat engineers play an essential supporting role in any
force as they enhance forcemobility for friendly troops and
hinderthemobilityofadversaries.Someactivitiesundertaken
bycombatengineersincludebridging,obstacleclearance,soft
groundmobilityenhancementaswellasmineandimprovised
explosivedevice(IED)neutralisation.
Traditionally,combatengineeringtaskshavebeenmanpower
intensive, time-consuming, logistically demanding and
dangerous.Now,technologicaladvancementsandinnovations
havecontributedtocombatengineeringinthreemainareas:(a)
automation toenable leanermanningofcombatengineering
equipment;(b)reductionoftimespentoncombatengineering
tasks; and (c) improvement of man-machine interfaces and
ergonomicstomakesystemssaferandeasiertouse.
This article presents and explores the role of technological
advances and innovations in the evolution of combat
engineeringequipment,withafocusonthreeareasofcombat
engineering tasks: fixed bridging, wet bridging, and mine
clearing.
PHUAZhengqiDaryl,TANChun,WONGYeeYinKimberly
ABSTRACT
Combatengineeringisessentialinenablingforcestoovercomediverseobstacles.Traditionally,combatengineeringtaskshavebeenmanpowerintensive,time-consuming,logisticallydemandinganddangerous.Now,moderncombatengineeringequipment requires less manpower and logistics to operate, features people-centric designs and allows tasks to becompletedinasaferandfasterway.
Thisarticleillustratestheroleoftechnologicaladvancementsandinnovationsincombatengineeringequipment,andshareshowcombatengineeringequipmentisexpectedtoevolveovertime.
Keywords:combatengineering,militarybridges,mechanised,mineclearing
FIXED BRIDGING
Military fixed bridges are required to be strong enough to
transportheavymilitaryvehicles,lightenoughtobetransported
easily and simple enough to be constructed quickly. Bridge
engineers use the concepts of bendingmoments and shear
forces to design efficient bridges to achieve the optimal
balancebetweenspan,strengthandweight.
ClassificationofBridges
Military bridges are classified by their Military Load Class
(MLC)inaccordancewithNATo’sStandardisationAgreement
20211. The MLC is a single number which represents the
strengthofthebridgeandclassofvehicleitcantransport,and
isproportionatetothemaximumbendingmomentandshear
forcethebridgecanwithstandwithoutundergoingirreversible
yield.
VehiclesaresimilarlyassignedanMLCratingdependentonthe
maximumbendingmomentandshearforceitexertsonabridge.
This isdependenton thevehicle’sweight, length,numberof
23DSTA HORIZONS | 2015
axlesandwheelloading.Thedeterminationofavehicle’sMLC
rating involves tedious calculations of the maximum shear
forceandbendingmomentover44predefinedbridgespans
foratotalof88testcases.DSTAhasdevelopedanin-house
applicationtoautomatethesecalculations,allowingengineers
toestimateavehicle’sMLCquickly.
InnovationsonModernFixedBridges
Modernfixedbridgeshavecomea longwaysince theearly
days, when crudely bundled brushwood called fascines
and one-piece bridges were used to cross tank ditches.
Technologicaladvancementsinweldingandthedevelopment
ofstrongermaterialshaveenabledmodernbridgestobelonger,
strongeranddeployedquickly.Someoftheseinnovationsare
asfollows.
Launching of Long Bridges
Carryingbridgessignificantlylongerthanthelaunchingvehicle
hampers the mobility of the vehicle and makes launching
unwieldy. To enable the launching vehicle to carry longer
bridges,thesebridgeswereinnovativelyfoldedinhalf,andthen
launchedbyunfoldingthemwithascissor-launchmechanism
(seeFigure1).However,scissor-launchedbridgeshavealarge
visualsignatureduringlaunching–posingchallengesforthem
Figure1.Scissor-launchmechanismonaM60A1AVLB(©Quihuis/File:M60A1ArmoredVehicleLandingBridge.jpg/http://www.news.navy.mil/view_single.asp?id=5015/PublicDomain)(left)andhorizontal-launchmechanismona
Leopard2ArmouredVehicleLaunchedBridge(ong,2013)(right)ReprintedwithpermissionfromDefenceMediaCentre(DMC)
tobelaunchedinareaswithoverheadobstaclesandmakingit
easierforenemiestospotthem.
Further improvements have been made to the designs of
assaultbridgesandahorizontal-launchmechanismhasbeen
developedinstead.TheLeopard2ArmouredVehicleLaunched
Bridge (AVLB), introduced into theSingaporeArmedForces’
(SAF)servicein2010,usesthehorizontal-launchmechanism
(seeFigure1).Anotheradvantageofthisdesignistheabsence
of hydraulic components in the bridge that improves its
reliabilityandservicelife.
Automation of Bridge Systems
Earlyfixedbridgeswereconstructedmanuallywhichcalledfor
significantmanpower and time.Thenewgenerationbridges
are launched by bridge layer vehicles with fully automatic
launching and retrieval modes operated by a crew of two,
whichcanlauncha26mbridgeinlessthaneightminutes.In
theLeopard2AVLB,thisismadepossiblethroughtheuseof
anelectronicallycontrolledhydraulicsystemandanarrayof
sensorsandactuatorsonboardthebridgelayervehicle.With
thesesensorsandcamerasmonitoringthelaunch,theoperator
isabletolaunchthebridgewithouttheneedtocomeoutofthe
vehicleandopenthehatch,making itsafer for theoperator.
24 DSTA HORIZONS | 2015
Figure2.M3g’sSchottelPumpJetup-close(C.Teuert,2014)(left)SchottelPumpJet360°movement(Schottelru,2011)(right)
forma100mbridgein25minutes-ascomparedtotheHeavy
AssaultBridgewhichrequired30trucks,60menand4hours
toconstruct.This isasignificantdecrease in themanpower,
logistics and construction time required. The technological
innovationsareasfollows.
Propulsion Systems
The earlier amphibious vehicles used a propeller for water
propulsion. The latest M3g utilises pump jets instead.
Traditionalpumpjetdesignsutiliseareversingbucketattached
totheendofthenozzletoachievereversethrustandbraking
ofthevehicleinwater,andplatestomanipulatethedirectionof
thejetforsteering.TheM3g’spumpjetisaninnovativedesign
where the nozzle can be rotated 360° to providemaximum
manoeuvrabilityofthevehicleinwater(seeFigure2).
Control System
The M3g has one pump jet at the fore and aft of the
vehicle, allowing the system to achieve a very high level of
manoeuvrability which a traditional propeller is unable to
achieve.Inordertocontrolthefullrangeofcomplexmotions
of the dual pump jets, an innovative control system was
implementedontheM3g(seeFigure3).Thisintuitivecontrol
allows the coxswain to retain full control over the complex
motionoftheM3gwithminimaltaskloading.
WET BRIDGING
Wet bridging (also known as float bridging) is a solution to
overcome long wet gaps which fixed bridges are unable to
overcome. This is done through the construction of float
bridges or forming of ferries. Wet bridges build upon the
principles of fixedbridging, but add a degree of complexity
withflotationconsiderations.
OriginsofWetBridgesandFerries
Wetbridginginvolvesthelinkingupofpontoonsorboatsuntil
thewetgapisbridgedoraraftofarequiredsizeisformed.The
traditionaltypesofwetbridgesolutionswerelogisticintensive,
and required multiple trucks to transport the pontoons,
tugboats, decks, ramps and associated accessories. For
example, a100massaultboatbridge requireda teamof60
men,20logistictrucksandover90minutesforconstruction.
InnovationsonModernFloatBridges
Compared to assault boat bridges and early amphibious
vehicles,modernfloatbridgesaremoreeffectiveandeasierto
operate.Forexample,theM3g,whichwasintroducedintothe
SAF’sservicein2008,requiresonlysixvehiclesand24mento
25DSTA HORIZONS | 2015
Furthermore, multiple vehicles connected together to form
a ferry canbenetworked for operationbya single console,
allowingasingleoperatorcontrolovertheferry.Thisimproves
thecontroloftheentireferryandenablesleanmanningofthe
system.
Reducing the Logistics Requirement of Float Bridges
PriortotheSAFacquiringtheM3g,thedesignoftheoriginal
equipment manufacturer (oEM) included three ramps per
vehicle. While this was adequate for the construction of a
Figure3.DemonstrationofthemarinecontrolsoftheM3g.Thelevelcontrolsthepowerandprimarydirection,andthe“horns”controltherelativerotationoftherig.
floatbridge, itwas insufficient for theconstructionofatwo-
vehicleferryinopen-coupleconfiguration2.Alogisticsvehicle
to transport the three additional ramps is required for this
configuration.
The SAF’s M3gs were modified to accommodate an extra
rampeach(seeFigure4).Modularpanelscanalsobeplaced
laterallybetweentworampstoformthethirdramp(seeFigure
5).Thisinnovationeliminatedtheneedforthelogisticsvehicle,
reducing the logistics footprint and achieving manpower
savings.
Figure4.oEM’sM3bridgewithonerampontheeachsideversusSingapore’sM3gwithtworampsoneachside.ThethirdramponoEM’sM3bridgeisstowedinthecentreofthevehicleandisnotvisible.
TECHNoLogICALADVANCEMENTSANDINNoVATIoNSINCoMBATENgINEERINgEQuIPMENT
26 DSTA HORIZONS | 2015
MINE CLEARING
Mine clearing is an important component in a combat
engineer’s tool list. The ability to clear a minefield quickly and
safely offers significant strategic and tactical advantage to the
force.
Mine Clearing Methods
Manual Methods – Mine Prodders and Metal Detectors
The most rudimentary method of clearing mines involves
personnel using mine prodders or metal detectors. These
methods relied on human operators to detect buried mines
before they could be neutralised, typically using a bomb-
disposal operator. Due to the close proximity of operators to
potential mines, these manual methods are time-consuming
and dangerous.
Figure 5. The modular panels of the M3G as a third ramp. The modular ramps are stored as seen on the right.
Mine Rollers and Mine Ploughs
Mechanised methods of mine clearing include using mine
rollers to trigger pressure sensitive mines, or mine ploughs to
push aside surface and shallow mines. However, mine rollers
are ineffective against mines which are not pressure activated,
and mine ploughs are only effective against shallow buried
mines on relatively soft ground.
Mine Flails
The method which provides the highest assurance of clearing
mines is the use of mine flails (see Figure 6). This method
employs a flail system to impact the ground physically to
neutralise mines. Modern mine flail vehicles have incorporated
the latest technology and innovations to allow soldiers to
clear a minefield faster, with less manpower and a high safety
margin. The SAF has two types of mine flailing systems – the
Mine Clearing Vehicle MCV910 and the Trailblazer Counter
Figure 6. Mine flail system on Singapore’s Trailblazer (Ong, 2013)Reprinted with permission from Defence Media Centre (DMC)
27DSTA HORIZONS | 2015
Mine Vehicle. The former was procured off the shelf with
customisationwhilethelatterwasdevelopedjointlybyDSTA
andSingaporeTechnologiesEngineering.
Mechanised methods enable the clearing of mines with
remarkably little effort compared to manual methods. The
latest innovations in mine clearing vehicles have made the
dangeroustaskofmineclearingsafer,fasterandpossiblewith
lessmanpower.
InnovationsinModernMineFlails
ThemineflailthattheSAFusescurrentlyincludesnumerous
innovationswhichmakeitsafetooperateandmoreefficientas
comparedtooff-the-shelfmineflails.Somemajorinnovations
areasfollows.
Hydro-Mechanical Continuously Variable Transmission
Whilemineclearingoperationsareconductedat lowspeeds
oflessthan1km/h,normaldrivingspeedsareupto70km/h.
Conventional vehicle transmissions are normally unable to
performwell at both low (less than 1km/h) and high (up to
70km/h)speedranges.
Instead of using two separate transmission systems3which
wouldrequireadditionalweightandspaceontheplatform,the
Trailblazerwasequippedwithahydro-mechanicalcontinuously
variable transmission which consists of a hydraulic pump
for the low speed range and a mechanically geared torque
convertor forhighspeed rangewithinasinglehousing.This
compactandlighttransmissionsystemenabledtheTrailblazer
tobecapableofboth extremely lowandhigh speedswhile
contributingtoweightandspacesavings.
Lane Marking System
ThelanemarkingsystemspeciallydesignedfortheTrailblazer
possesses pneumatically fired rods. Compared with other
systemsthatemploypyrotechnicfiring,thepneumaticsystem
enables safer andmore accurate lanemarking. Tominimise
the workload on the operators, the lane marking system is
deployed hydraulically and can be retracted with ease for
stowagefromthecrewcabin.
Fully Automated Control
ThefullyautomatedsoftwarecontroloftheTrailblazerreduces
the operator workload and sustains the operator for longer
missions. The software control achieves auto-contouring
effect for complete mine clearing. This creates operational
flexibility for theoperator toclearundulatingcontourswhen
necessary.Coupledwiththepneumaticlanemarkingsystem,
theTrailblazer is able to clear andmark the lane for follow-
onforcesautomaticallywithsignificantly lesseffortandtime
comparedtopastsystems.usingdigitalcontrolalsoenables
mobility to be controlled with a joystick, presenting better
ergonomicsfortheoperatoroverlongmissions.
FUTURE TRENDS
Combatengineerequipmenthasbenefittedfromtechnological
advancements and innovations over the years. This section
exploresthepotentialevolutionofcombatengineerequipment.
AdvancedMaterials
The advancement of materials technology will play a
significantroleinthefutureofcombatengineeringequipment.
one promising area is the use of composites in float and
fixed bridges which will bring about lighter, stronger and
longerbridges.However,theuseofcompositesisnotwithout
disadvantages.otherthancost,theuseofcompositesposes
severaltechnicalchallenges.
The maintenance of composite material structures is more
challenging than conventional material structures used in
bridges like steel or aluminium alloys. While conventional
materialscanberepairedbywelding,therepairisconsiderably
more complex if a delamination occurs between the fibre
and matrix in a fibre composite structure. Furthermore, the
delaminationmay not be visible to the operatorwhowould
not be able to sense the need formaintenance even when
potentially severe damage has occurred. Hence, more
experienceandexpertisearerequiredtomaintaincomposite
structures. Composites are also very sensitive to flaws
sustained during the manufacturing process as compared
to metals. Any deviation from a tightly controlled process
may lead to a compromise in thematerial properties of the
composite. These factors contribute to the high cost of
incorporatingcompositesincombatengineeringsystems.
However,asmoreadvancedcompositesaredeveloped, the
useof composites couldbemore cost effective. This could
resultinatrendtowardstheuseofmorecompositesincombat
engineeringsystems.
TECHNoLogICALADVANCEMENTSANDINNoVATIoNSINCoMBATENgINEERINgEQuIPMENT
28 DSTA HORIZONS | 2015
REFERENCES
C.Teuert(personalcommunication,September1,2014)
ong, H. T. (2013, June 3). Engineers roll out. Retrieved
from http://www.mindef.gov.sg/imindef/resourcelibrary/
cyberpioneer/topics/articles/features/2013/jun13_cs.html
Quihuis,K.,Jr.(2003,February6).File:M60A1ArmoredVehicle
Landing Bridge.jpg. In Wikimedia Commons. Retrieved
october 7, 2014, from http://commons.wikimedia.org/wiki/
File:M60A1_Armored_Vehicle_Landing_Bridge.jpg
Schottelru. (2011, November 16). Schottel SPJ [Video
file]. Retrieved from http://www.youtube.com/watch?v=c_
F4uZ5BKHy
ENDNOTES
1 The Standardisation Agreement 2021 MILITARy LoAD
CLASSIFICATIoN oF BRIDgES, FERRIES, RAFTS AND
VEHICLES is a standard for NATo forces that provides
methodsforcomputationofMLCforbridges,ferries,raftsand
vehicles(bothtrackedandwheeledvehicles).
2 Thisconfiguration is ideal as it notonlyprovidesa larger
deck space for ferrying vehicles, but also increases the
metacentricheightforadditionalstability.
3 The transmission systems comprise a mechanical
transmissionforhighspeedtravellingandahydrostaticdrive
for low speedmine clearing. This is because a mechanical
transmissionisunabletoprovidehightorquesandisinefficient
at lowspeeds,whereasahydrostaticdrive suffers from low
efficiencyandexcessivelossesathighspeeds.
AutonomousEquipment
Althoughunmannedtechnologyisrelativelymature,ithasnot
beenwidely implemented incombatengineeringequipment.
onemainfactor iscost.Asunmannedtechnologiesbecome
morecosteffective,therecouldbemoredrive-by-wirecombat
engineering systems to enable the development of remote-
controlledandautonomoussystems.
Fully autonomous equipment will require sufficient artificial
intelligence(AI).AsAItechnologyimprovesinthefuture,it is
likely that systems for dull, dirty and dangerous tasks such
asmineclearingwillmakethefirstpushtofullyautonomous
systems.
ImprovisedExplosiveDeviceNeutralisation
Inthefuture,IEDswillpresentoneofthebiggestchallengesfor
combatengineers.Currenttechnologyincludesradiojammers
and ground penetrating radar systems, but these solutions
havetheirshortcomings.Futuredevelopments in theareaof
IED neutralisationwould likely include high energyweapons
suchashighpoweredmicrowavesand lasers todisrupt the
electronicsanddetonatorsinIEDs.
CONCLUSION
There have been great technological advances in combat
engineering equipment over the years. These advances,
particularlyinautomation,havebeenleveragedinthesystems
used by the SAF. The benefits include a leaner operating
force,more ergonomic systems, aswell as safer and faster
completion of combat engineering tasks. Besides utilising
technology, innovations in design have also played a role
in reducing the logistic requirements of the systems. While
technology continues to advance, it would take time for
these advancements to be adopted in combat engineering
equipment, due to the difficulties and high cost associated
withimplementationcurrently.
ACKNOWLEDGEMENTS
The authors would like to express their appreciation to
MrPatrickDRozario andMr Teo Tiat Leng for their patient
guidanceandinputsinpreparationofthisarticle.
29DSTA HORIZONS | 2015
BIOGRAPHY
PHUA Zhengqi Daryl is a Project
Manager (Land Systems) involved in
the acquisition of combat engineering
systems. He was formerly involved in
armoured vehicle projects and was a
System Manager in Headquarters,
Maintenance andEngineeringSupport in
theArmy.Daryl graduatedwith aMaster
ofEngineering (MechanicalEngineering)degreewithFirstClass
Honours from Imperial College London, uK, in 2009 under the
DSTAundergraduateScholarshipprogramme.
TANChun isaProgrammeManager(Land
Systems) overseeing the acquisition of
combat engineering systems for theArmy.
He has extensive experience in managing
projects in the areas of military bridges,
mine clearing vehicles, engineering plants
and lightseavessels.TanChungraduated
withaBachelorofEngineering(Mechanical
Engineering) degree from the National university of Singapore
(NuS) in1993.HefurtherobtainedaMasterofScience(Military
Vehicle Technology) degree from the Royal Military College of
Science,uK, in2001undertheDSTAPostgraduateScholarship
programme.
WONG Yee Yin Kimberly is an Engineer
(Land Systems) who is currently involved
in the acquisition management of combat
engineer systems. Kimberly graduated
withaBachelorofEngineering(Mechanical
Engineering)degreefromNuSin2013.
TECHNoLogICALADVANCEMENTSANDINNoVATIoNSINCoMBATENgINEERINgEQuIPMENT
30 DSTA HORIZONS | 2015
DELIVERINgNEWMINECouNTERMEASuRECAPABILITIESToTHERSN
INTRODUCTION
AnondescriptcargoshiptraversestheStraitofSingaporeand
releasesacylinderdiscreetly intothewater.Later,aRepublic
ofSingaporeNavy(RSN)MineCountermeasureVessel(MCMV)
RSSBedokisperformingaroutinesurveywhenitsminehunting
sonar1 detects a cylindrical object lying on the seabed. A
lightweightunderwaterinspectionvehicleisdeployedremotely
to investigate and visual confirmation via its fibre-optic link
showsthattheobjectisindeedaseamine.
ThisinformationissentbacktotheMaritimeSecurityTaskForce
Headquarters and patrol vessels are dispatched immediately
tocordonoff theaffectedarea.RSSBedok then launchesa
lightweightexpendableminedisposalvehiclewhichdetonates
theminesafely.
ThisisahypotheticalbutpossiblescenariothattheRSNMine
CountermeasureSquadronmayfaceintheirmissiontokeep
theStraitofSingaporesafeforshipping.
TheMCMVsplayanimportantroleinthemaritimesecurityof
Singaporebyensuringthatitssurroundingsealanesandthe
GOHYongHan,LAMSuYingAudrey
ABSTRACT
AnymineincidentintheSingaporeStraitwouldseverelyimpactSingapore’seconomy.Assuch,theRepublicofSingaporeNavy(RSN)MineCountermeasureVessels(MCMV)formthemainstayoftheSingaporeArmedForces’underwaterminecountermeasurecapability.TheBedok-classMCMVsoftheRSNwereoperationalisedin1995.In2009,amodernisationprogrammewasintroducedtoupgradetheMCMVs’minecountermeasurecapabilitiessoastoenhancetheirminehuntingandneutralisationrate.Thisarticlediscussesthethreatswhichseaminescanpose,theprojectandtechnicalchallengesindeliveringtheminecountermeasurecapabilitytotheRSN,andthesystemengineeringbasedapproachadoptedbytheprojectmanagementteaminovercomingthesechallenges.
Keywords:minecountermeasure,minehunting,minedisposal
SingaporeStrait are freeandopen to international shipping.
Thelayingofminesbypotentialadversariesorterroristsinthe
SingaporeStraitor inoursealinesofcommunicationscould
leadtoportclosure,whichwouldresultindirecttradelosses
amountingtomorethanS$2billiondaily2.
THE SEA MINE THREAT
Seamines are explosivedevicesplaced inwater todestroy
surface ships or submarines (Wikipedia, n.d.). They range
frombottommines,mooredmines,driftingorfloatingmines
to limpetminesattacheddirectly to thehullsof targets.Sea
minesare laidand left towaituntil theyare triggeredby the
approachof,orcontactwith,anenemyvessel.Theseamine
is a lethalweapon that datesback to themid-19th century.
They are low-cost weapons which are extremely difficult to
detect, identify and destroy, presenting a significant threat
eventothemostsophisticatedwarshipstoday.Figure1shows
apictureofaBritishMk14seamine.Seamineshaveevolved
over time from the early low-cost contactmines tomodern
influencemineswithmagnetic,acousticandpressuresensors.
Advanced influence mines with modern signal processing
31DSTA HORIZONS | 2015
capability can be triggered by pre-determined logic or pre-
programmed characteristics of a particular class of ship or
submarine’ssignature.
TheCommitteeforMineWarfareAssessmentoftheuSNaval
StudiesBoard(2001)describesthestrategicuseofmines in
thedenialofpassagethroughconfinedwatersandtheentryor
exitofportsofcoastalnations.Minesareasymmetricweapons
and can influence a war campaign greatly. For example, in
WorldWarII,miningbytheAlliesachievedsomeremarkable
successes. During the Atlantic War lasting five years, the
RoyalAirForce(RAF)flew20,000mine-layingsorties,sinking
638 shipswith the loss of 450 aircraft. In comparison, RAF
bombsand torpedoessank366shipsover thesameperiod
withthelossof857aircraft.DuringtheTankerWar3in1988,
theguidedmissilefrigateuSSRobertswasheavilydamaged
byadrifting Iranianmineand theuSNavyspentmore than
uS$90 million to repair the damage (see Figure 2). In the
1991gulfWar, Iraqimines hindereduS amphibious assault
planningandheavilydamaged twouSwarships,preventing
them from further operations. For inferior forces, mines are
particularlyvaluabletodefendagainstasuperiornavalforce.
Sea mines are available widely and are often more difficult
Figure1.BritishMk14SeaMine(©oxyman/File:BritishMk14SeaMine.jpg/WikimediaCommons/CCBy-SA3.0)
andtime-consumingtoneutralisethanairandmissilethreats.
SinceWorldWarII,14uSNavyshipshaveeitherbeensunkor
damagedbymines,ascomparedtoonlytwowhichhavebeen
damagedbyairormissileattacks.
DELIVERING NEW MINE COUNTERMEASURE CAPABILITIES TO THE SINGAPORE NAVY
The RSN’s four Bedok-class MCMVs were acquired from
Sweden and commissioned in 1995. In view of their ageing
systems and the advent of new technologies, DSTA
embarked on a modernisation programme for the MCMVs.
Thisprogrammecommenced in2009with the installationof
an advanced and integrated mine countermeasure combat
system,comprisingaMineInformationSystem,HullMounted
MineHuntingSonar (MHS),TowedSyntheticApertureSonar
(TSAS) and Expendable Mine Disposal System (EMDS)
(see Figure 3). The approaches taken by the DSTA project
management team (PMT) to deliver these new capabilities
successfullyaredescribedinthefollowingsections.
32 DSTA HORIZONS | 2015
Figure3.Newminecountermeasuresystemsinstalled
Figure2.Theeight-metreholeinthehullofguidedmissilefrigateuSSRobertscausedbyanIranianM-08mine(©Mussi/File:Ffg58minedamage2.jpg/u.S.Navy/ID:DNST8902266/PublicDomain)
33DSTA HORIZONS | 2015
ManagingaComplexUpgradingProjectWithaLeanPMT
The conventional approach to managing a Life Extension
Programme (LEP)ofanaval vesselof suchcomplexity is to
form a core integrated PMT of more than 10 engineers to
overseemajorcombat,platformandshoresystems.ThePMT
adoptedaprimecontractorapproachtominimisethesizeof
theteamafteracarefulstudy.Theprimecontractorsupplied
themajorityofthesystems,installedandintegratedthemwith
existingsystems,andwasresponsiblefortheperformanceof
thetotalsystem.ThisallowedacorePMTofhalf thetypical
sizetomanagetheentireLEP.
ManagingDevelopmentalItemsDuringContracting
During the tender exercise in 2008, all submitted proposals
had some key systems that were still in the high risk
development phase due to the demanding technical
performance specifications of the tender. By applying the
procurement principles of competition and value formoney,
thePMTemployedcompetitivebiddingexercisesandincluded
contractual clauses to protect our interests in the event of
possible failure of the developmental systems. This ensured
thetenderreturnswouldbecosteffective,withacceptablerisk
managementmeasuresputinplacebyeachofthetenderers.
AchievingCostEffectivenessDuringContracting
ThePMThadoriginallymandatedalltendererstoengagethe
originaldesignerof theMCMVas theplatformconsultant to
oversee theplatformmodificationworksasa riskmitigation
measure. Subsequently, the PMT conducted a thorough
technicalriskassessmentandexploredengaginganalternate
platform consultant with the tenderers to achieve greater
costeffectiveness.ThePMTconducteddetailedshipsurveys
on each MCMV, reviewed the existing documentation and
drawings,anddeterminedthatminimalplatformmodifications
wererequired.Allrequiredinformationcouldalsobeobtained
throughmeasurements.By systematically going through the
risks of modification and integration, the PMT selected an
alternate platform consultant with experience in managing
MCMVplatformupgradingandachievedfurthercostsavings.
Withtheaddedriskassessmentandmanagementprocesses
putinplacecontractuallyandthroughprojectmilestonereview
meetingsandprogressivemonitoring,thisapproachledtothe
effectiveandsuccessfulexecutionoftheprogramme.
ManagingIntegrationRiskWithLegacySystems
The delivery of the upgraded programme capability was
heavilydependentonthesuccessfulintegrationoftheexisting
systemswiththenewsystems.This isamorecomplextask
comparedtonew-builtprogrammesassomeoftheinformation
required for integration is not available for some legacy
systems. To mitigate this risk, pre-condition assessments
(PCA) were performed to establish and record the baseline
configuration of the ship through a series of inspections
and tests.Thisenabled the reconstructionandextractionof
missinginformation.Atthesametime,thePCAservedtoverify
thelegacysystems’performanceandinterfacespecifications
tofacilitateintegrationwiththenewsystems.
DeliveringImprovedMineHuntingCapability
underwater mines are located using sonar which is
traditionally a slowand tediousprocess.With the advent of
new technologies, e.g. the synthetic aperture sonar (SAS),
minehuntingcanbeperformedbetterandfaster.Theprinciple
ofSASistocombinesuccessivepings4alongaknowntrack
coherently inorder to increase the resolutionof theazimuth
direction(along-track).Hansen(2011)explainedthatwiththis
increased “synthetic aperture” length, the sonar is able to
obtainhigher resolution imageswith respect toconventional
sonarprocessing.
ThecoveragerateforaTSASisaboutfivetimesfaster than
the legacy hull-mounted MHS. This is achieved due to a
highersurveyspeedandwidersonarswathwidths(seeFigure
4). Being hull-mounted, the one-sidedMHS array limits the
MCMV speed during survey,while the TSAS is a two-sided
arrayabletocovermorearea,andcanbetowedatahigher
speed to achieve amuch higher coverage rate. In addition,
theTSASprovidessignificantlyhigherresolutionforimproved
classification capability5. The new TSAS also offers an
automaticdetectionandclassificationcapability to ease the
operator’sworkloadinminedetectionandclassification.
DELIVERINgNEWMINECouNTERMEASuRECAPABILITIESToTHERSN
34 DSTA HORIZONS | 2015
Compared to the previous sonar system which was
hull-mountedandnottowed,thePMTconductedanextensive
safetyreviewontheproceduresprovidedbythecontractors
for the launching, recovery and towing operations. All the
emergencysafety featuresof theTSAS, suchasemergency
surfacing, cable breaking tensions and emergency stops,
were individually analysedduringdesign reviewsand tested
thoroughly during sea acceptance tests to ensure safe
operations. The launch and recovery procedures were also
improvedandsimplifiedthroughnumerousseatrials.
DeliveringImprovedMineNeutralisationCapability
Theminedisposalsystem(MDS)hasbeenusedbytheRSN
for mine neutralisation since 1995. The vehicle used in the
MDSweighsabout900kgandrequiresacraneandhandling
systemforlaunchingandrecoveryduringmineneutralisation
missions.AspartoftheMCMVmodernisationprogramme,a
newEMDSwasacquiredandinstalledonboardtheMCMVs.
TheK-Ster6EMDS is capableof identifyingandneutralising
mine-like objects to support the mine clearance operations
of the RSN. It is a remotely operated vehicle that consists
of a lightweight vehicle and supporting shipboard systems.
The vehicle has two configurations – the K-Ster Inspection
for identification of mine threats, and the K-Ster Combat
for neutralisation of mines. The expendable K-Ster Combat
vehicleisdesignedtoneutraliseaminewithasingleshot(see
Figure5).
This vehicle has led to vast improvements in mission
effectivenessasitislightweight,simpletooperateandeasyto
deploy.At50kg,itislessthan10%theweightoftheprevious
MDSvehicle,and its lighterweightsimplifiesthe launchand
recoveryprocess. It isestimated that theoperation timeper
mine is reduced by about half. Equipped with just a small
charge,thevehicleisdesignedwithatiltablewarhead,sonar,
sighting laser, video camera and searchlights to locate and
attackminesaccuratelyandefficiently.
TheK-SterCombatvehiclesarestoredintheEMDSmagazine
onboardtheMCMVs.Tominimisemanualhandlingofvehicles,
thePMTworkedcloselywiththeprimecontractortodesigna
setofcustomisedjibsandfixturestofacilitateamoreefficient
transferofK-SterCombatvehicles.
Figure4.(a)MHStransmissionpattern(b)TSAStransmissionpattern
(a) (b)
35DSTA HORIZONS | 2015
TheRSN is the first navy in theworld to conduct live-firing
using this vehicle. As this is a new weapon system, there
were no previous firing templates or references. The PMT
collaboratedwiththeRSNtodeveloptestscenariosandsafety
firing templates. Subsequently, with the knowledge gained
fromthefirstfiring,thePMTworkedoutanewweapondanger
area template which significantly reduced the safety radius
comparedtothefirstfiring.Thisachievedfurthercostsavings
intermsofassetsandtimerequiredforsafetyclearance.
Inaddition,overtheseveralseatrialsandlive-firing,thePMT
enhanced the preparation procedures progressively, and
implemented additional instrumentation to further automate
thepre-launchprocess.Theseservedtoreducethepreparation
timeneededbeforeeachfiring.
CONCLUSION
Through the application of the system engineering based
approach, the PMT had successfully completed the
MCMVmodernisation programme for the RSN in 2014 in a
cost-effectivemanner.Thishasresultedinnewandenhanced
mine countermeasure capabilities to keep Singapore’s sea
lanesmine-freeandsafe.
Figure5.K-Stervehicleapproachingatarget
REFERENCES
Bedokclassminecountermeasurevessels.(n.d.).InWikipedia.
Retrieved July 14, 2014, from http://en.wikipedia.org/wiki/
Bedok-class_mine_countermeasures_vessel
Committee for Mine Warfare Assessment, Naval Studies
Board,DivisiononEngineeringandPhysicalSciences,National
ResearchCouncil.(2001).Navalminewarfare:operationaland
technicalchallengesfornavalforces.Retrievedfromwww.nap.
edu/openbook.php?record_id=10176
Hansen,R.E.(2011).Introductiontosyntheticaperturesonar.
InN.Z.Kolev(Ed.),Sonarsystems(pp.3-27).Rijeka,Croatia:
InTech.doi:10.5772/23122
Mussi, C., PH1. (1988, May). File:Ffg58minedamage2.jpg.
InWikimediaCommons.RetrievedJuly14,2014,fromhttp://
commons.wikimedia.org/wiki/File:Ffg58minedamage2.jpg
oxyman.(2007,December1).File:BritishMk14SeaMine.jpg.
InWikimediaCommons.RetrievedJuly14,2014,fromhttp://
commons.wikimedia.org/wiki/File:British_Mk_14_Sea_Mine.jpg
DELIVERINgNEWMINECouNTERMEASuRECAPABILITIESToTHERSN
36 DSTA HORIZONS | 2015
ENDNOTES
1 Sonar stands for sound navigation and ranging, and is a
techniquethatusessoundpropagationtodetectobjectsonor
underthesurfaceofthewater.
2 Singapore’stotaltradein2013wasS$980billionbasedon
theMinistryofTradeandIndustryfigures,ofwhichabout80%
orS$784billionwastransportedviaseabornemeans.
3 TheTankerWarreferstotheanti-shippingcampaignsduring
the Iran-IraqWar (1980-1988). In1981, Iraq initiatedattacks
onshipstoweakenIran’swarfightingcapability,startingwith
ships carryingmilitary supplies to the groundwar front and
subsequentlyattackingmerchantshipscarryingIran’sexports.
Iranretaliatedinasimilarfashion,attackingshipsbelongingto
Iraq’stradingpartnersandtocountriesthatsupportedIraq’s
wareffort.In1987,theuSjoinedthewaruponKuwait’srequest
toofferprotectiontoKuwait’stankerfleet.WithuSwarships
patrolling thegulf, Iranstarted tosowthegulfwithanti-ship
mines. This resulted in severaluS ships beingdamagedby
Iranianmines,includingtheguidedmissilefrigateuSSSamuel
B.Roberts(FFg-58)inApril1988.
4 Thetransmissionofsoundwavesunderwateriscommonly
referredtoaspings.
5 Withthehigherresolution,betterclassificationisachieved
as there are more pixels associated with the object under
investigationtocomputeitssizeandshapemoreaccurately.
6 TheK-SterEMDSisaproductofECARobotics,France.
BIOGRAPHY
GOHYongHan is aProgrammeManager
(Naval Systems) managing the Mine
Countermeasure Vessel (MCMV) upgrade
programme. He has worked on the
Challenger-class submarine upgrade,
undertaken defence R&D at DSoNational
Laboratories and managed research and
technology projects at the Ministry of
Defencebeforeassuminghiscurrentrole.ArecipientofthePublic
Service Commission Scholarship, yong Han graduated with a
Bachelor of Engineering (Electrical Engineering)with FirstClass
HonoursfromtheNationaluniversityofSingapore(NuS)in1997.
HefurtherobtainedaMasterofEngineering(ElectricalEngineering)
degreefromNuSin1998undertheNuSResearchScholarshipas
wellasaMasterofScience(ElectricalandComputerEngineering)
degreefromtheuniversityofCalifornia,SanDiego,uSA,in2007
undertheDSTAPostgraduateScholarship.
LAM Su Ying Audrey is a Systems
Architect (DSTA Masterplanning and
Systems Architecting) currently supporting
themasterplanningandoperationsconcept
formulation with the Singapore Armed
Forces. She was previously a Senior
Engineer at Naval Systems Programme
Centre,wheresheledthedeliveryofseveral
naval systems, including naval guns on the Formidable-class
frigatesandthenewminecountermeasurecombatsystemsinthe
MCMVupgradeprogramme.Audrey graduatedwith aBachelor
ofEngineering(MechanicalEngineering)degreeandaMasterof
Science(IndustrialandSystemsEngineering)degreefromNuSin
2004and2007respectively.
37DSTA HORIZONS | 2015
DELIVERINgNEWMINECouNTERMEASuRECAPABILITIESToTHERSN
38 DSTA HORIZONS | 2015
EWoRKPLACE:EVoLVINgDSTA’SKNoWLEDgEMANAgEMENTJouRNEy
INTRODUCTION
Since embarking on its Knowledge Management (KM)
journey in 2003, DSTA has attainedmajormilestoneswhich
includedthecreationoftheeHabitatIntranetPortal,theDSTA
Extranet platform, as well as the Content and Document
ManagementSystem–DSTA’srecordsrepositorythatarchives
enterprisecontent,collaborationtools,andActionandIssues
ManagementSystemmeetingtools.
From2003 to 2009, thegrowthofKM inDSTAwasevident
from the usage of different KM applications and tools, to
thecontributionofdocumentsandsharingof information.A
community of Knowledge Managers, who acted as change
agentsfortheirrespectiveentities,wasalsoestablishedtohelp
proliferatetheground-upadoptionofKMintheorganisation.
ThefollowingphaseofDSTA’sKMjourneywasintransforming
its eHabitat Intranet platform from an information-centric
to a social-centric workplace. This involved implementing
enterprise social collaboration through the use of modern
web technologies and user-centric design. Enterprise
social collaboration describes the technologies and
processes used to boost collaboration in the workplace.
KOOYihLiangKevin,LIMLayHarEvon,HOWeiLingAngela,SOHYunLinJason
ABSTRACT
It has been more than a decade since DSTA embarked on its Knowledge Management (KM) journey in 2003.The next step in DSTA’s KM journey lies in the evolution of its Intranet portal from an information-centric to asocial-centric workplace.
ThisarticledescribeshowDSTAimplementedenterprisesocialcollaborationinitsIntranetportalthroughtheuseofmodernwebtechnologiesanduser-centricdesign.Thishascreatedaconduciveenvironmentto improveengagement, learning,collaborationandproductivitywithintheorganisation.
Keywords:collaboration,knowledgemanagement,sharepoint,socialcollaboration
Thisnewwaveshifted theparadigmofhowpeoplecreated,
stored and shared knowledge by leveraging Web 2.0 and
socialcomputingtools.ItwasthustimelyforDSTAtorideon
theseemergingtechnologiestoaddressexistinggapsinKM,
redefineitslandscapeandtransformthewaystaffwork.
At the same time, there were significant changes in the IT
landscape of DSTA and the Ministry of Defence (MINDEF).
These changes included network separation1, heightened
security concerns and an increased need for cross-domain
collaborationtosolvecomplexandlarge-scaleproblems.
These were the driving factors behind the transformation
of DSTA’s eHabitat Intranet platform into its current form –
eWorkplace.
eWorkplace is DSTA’s next-generation digital workplace
designed to transform how people create, organise, store,
search,useandshareknowledge.Asaresult,itwillenhance
workeffectiveness,knowledgesharingandengagementwithin
theorganisation.
39DSTA HORIZONS | 2015
EWORKPLACE STRATEGY
ThebasisoftheeWorkplacetransformationinvolvedamove
fromacontentstrategytoaconnectionstrategy(seeFigure1).
ContentstrategyfocusesoncodifyingknowledgeinDSTAinto
reusableknowledgeassetsthatarestoredintorepositoriesto
beretrievedatalatertime.Italsofocusesonthemanagement
ofenterpriserecords.Codifyingknowledgeassetsmaximises
knowledge retention and the efficient reuse of knowledge
assets.
Figure1.DSTA’sknowledgestrategyshift
Connection strategy focuses on connecting people to
collaborate and solve problems by tapping their collective
wisdom. Italso involvesconnectingpeopletocontent inthe
repositoriesthroughefficientsearchandretrieval.Connection
strategyemphasises thecreationofnewknowledgethrough
the building ofDSTA’s enterprise social network to facilitate
people-to-peopledialogueandcollaboration.
EWORKPLACE PARADIGM OF SPACES
The basic tenet of eWorkplace is thus centred on DSTA’s
paradigmofthreemainspaces:corporatespace,teamspace,
andpersonalspace(seeFigure2).
Figure2.DSTAeWorkplaceparadigmofthreespaces
40 DSTA HORIZONS | 2015
Corporate space is the authoritative source of all official
enterprisecontentandan importantcommunicationchannel
for staff. In addition to information dissemination, it should
leverage social computing tools to provide a role-based,
seamlessandmultimodalworkexperiencefortheenduser.
Team space is a contextualised one-stop page for staff
to collaborate, store, access and work on shared content
together.
Personal space is a personalised page for staff to manage
theirownproductivity.Italsoservesasaone-stopchannelto
providespecific informationtostaffbasedontheiractivities,
memberships and subscriptions within the workplace. In
addition,staffusethisspaceasaplatformforsocialnetworking.
DESIGN PRINCIPLES
To ensure a simple and secure platform, eWorkplace was
designedwiththreemainprinciples:
a) One-stopSecured and Integrated Front – Staffwould
be able to find information they need quickly and easily via
aone-stop integratedfrontwhichpools together information
fromdisparatesources.
b) Person-centric – The emphasis would be on the
individualandhowheor sheworks.Staffwouldexperience
ahighlypersonalisedexperience via intuitiveuser interfaces
andreceivecontextualised informationthrough, forexample,
subscriptionsandnotifications.
c) Process-centric – As a large part of work in DSTA
revolvesaroundprocesses,therewasaneedforeWorkplace
toenablestafftocomplywithprocessesviaacontextualised
andpersonaliseduserinterface.
TRANSFORMING DSTA’S WORKPLACE USING ENTERPRISE SOCIAL COLLABORATION
Locating a subject matter expert, social commenting and
accessingnewsfeedsandenhancedsearchfeaturesaresome
of the newnorms that have changed thewaypeoplework,
shareinformationandincreaseproductivityinanorganisation.
Therewas a lackof social tools inDSTA’sprevious Intranet
platform.Theprojectteamthusevaluatedseveraltechnologies
and selected a reliable and powerful platform that could
providecollaboration,socialmedia,search,enterprisecontent
managementandbusinessintelligencefeatures.
Collaboration,LearningandSharing
Communitiesofpracticeandteamsitesallowstafftoshareand
acquirenewknowledgeandinsightseasily.WithineWorkplace,
staff can share tacit knowledge through noteboards, blogs
anddiscussionforumswithinthecorporateandteamspaces.
An examplewouldbe the eLibrary, a central repository that
consolidates and shares technical documents authored by
DSTAstaff2.Itenablesstafftoconductwork-relatedresearch
into technicaldocuments thatareeitherproducedbyastaff
through thecourseofaprojectorby independent research.
eWorkplace provides a proper underlying file structure and
classification system for the sharing of these technical
documents.
AseWorkplace isan integratedenterpriseproductivitysuite,
the user experience in performing co-authoring and review
duringcollaborationisenhancedgreatly.Withofficewebapps
and different service applications powering eWorkplace and
the enterprise productivity suite, multiple authors are now
able to review and edit different segments of a document
simultaneously.
For traditional users accustomed to checking in and out
files, eWorkplace has transformed the way they work.
Building on existing versioning conventions, eWorkplace
allows differentiation between published and draft versions
of documents. Workflows can also be put in place if there
is a need to set up a formal approval process for sensitive
documentsthatrequireapprovalbeforepublication.
Staff can also keep up to date on documents that are of
importance to them by subscribing to alerts via e-mail and
newsfeedspushedtotheirpersonalpagesandteamsites.
Wikipage isanothersocialcollaboration toolwhichcollates
authoritativeandinformativecontenttopromotestafflearning.
TheeaseofuseofaWikipageasacontentpublishingtool
encouragesuserstocreateandsharecontentwiththerestof
theorganisation.
41DSTA HORIZONS | 2015
StaffEngagement
onefundamentalshiftforeWorkplacewasfromaninformation-
centrictoasocial-centricparadigm.Managementblogswere
developedtoallowmanagementtosharetheir thoughtsand
engagestaffinaninvitingandaccessibleenvironment.Through
social networking capabilities, staff are able to comment on
theseblogpostsandcontributeopinionsandfeedback.They
canalsosubscribetotheseblogstokeepabreastofanylatest
development.
Communitydiscussion forumscanalsobeusedtogenerate
social conversations and feedback related to specific
organisation initiativesandevents.Forexample,prior to the
DSTAStaffConference, a community discussion forumwas
usedtogatherfeedbackfromstaffonpertinentengagement
issues which were subsequently addressed during the
conference.
Thisallowsmanagementtosensethepulseoftheorganisation
constantlyandreceivefeedbackdirectlyfromtheground.
PersonalProductivity
one key innovation and a cornerstone of eWorkplace was
the consolidation of disparate information into a one-stop
personalpage.Previously,usershad tonavigate todifferent
pages of interests to retrieve information. Now, they can
receiveupdatesfromthesepagesinstantlythroughnewsfeeds
andnotifications.
The new personal page feature in eWorkplace also serves
as a directory that profiles each individual staff within
the organisation. Staff can list down their expertise and
competencies,whicharecombinedwithpertinentinformation
suchassecondaryappointments.Thisenablesstafftolocate
subjectmatterexpertsandalsoprovidesaplatformforstaffto
developsocialnetworkswithintheorganisation.
The newsfeed and notifications features allow staff to stay
updatedonlatesthappeningsinaproductiveandinteractive
manner.Staffmembersareable to subscribe to siteswhich
theyareinterestedinandreceivenewsfeedsonupdatesmade
to these sites. Staff can also receive notifications regarding
eventstheyhaveregisteredfor,taggeditems,socialactivities,
upcomingmeetingsandassignedtasks.
Furthermore,eWorkplaceprovidesTwitter-likefeaturestostaff
microblogs. Inaddition toallowing imagesandvideos tobe
postedwithstatusupdatesforricherinteraction,eWorkplace
alsointroducedhashtagsandmentionstocreateanimmersive
digitalequivalentofa real-timeconversationandnetworking
session.
When staff follow a hashtag, they will be notified via their
newsfeedoncurrentconversationsofinterestforthemtojoin.
New anddirect connections can also bemade among staff
throughtheuseofmentionswithinconversations.
Tofurtheraugmentproductivity,eachstaffwasprovidedwith
apersonalrepositorytostoreprivatefiles.Thisallowsstaffto
accesstheirfilesfromanywherewithinDSTA.
CorporateinformationontheIntranetwasreorganisedintoa
newlydefinedinformationarchitecture.Policiesandguidelines
were consolidated into a one-stop site instead of disparate
corporate portals. Access to services, like transactional
applications and online forms, was also centralised. This
improved information architecture enhanced information
findabilityandoveralluserexperienceandproductivitygreatly.
InnovationandCrowdsourcing
Socialcollaborationtoolsprovidecrowdsourcingcapabilityto
complementproblem-solvingandidea-generatingprocesses.
Through the use of discussion forums, tags and ratings
features, staff can contribute ideas and opinions on various
contentthroughouttheworkplace.Thisinfluencesthevisibility
of salient information and contributes to the innovation
process.
Introduction of implicit (hashtags) and explicit (mentions)
waysforstafftonetworkandengagewithoneanotherwithin
eWorkplacealsoallowsmulti-dimensionalchannelstopromote
crowdsourcingandinnovationintheorganisation.
ReliableInformationatOne’sFingertips
ThesearchfeatureineWorkplaceusesanewrankingmodelto
determinetheitemstodisplayandtheorderinwhichresults
aredisplayed.Behindthescenes,theanalyticscomponentin
eWorkplace tracks and analyses how content is connected
continuously,howoftenanitemappearsinsearchresultsand
whichsearchresultspeopleclickedtodetermineandimprove
the relevance of search results. Previously searched results
EWoRKPLACE:EVoLVINgDSTA’SKNoWLEDgEMANAgEMENTJouRNEy
42 DSTA HORIZONS | 2015
Though thepreviously released versionwouldbe supported
until 2020, the project team recognised the importance
of harnessing advances in technology to optimise current
investments and future-proofDSTA’s IT landscape. Thenew
product version would also improve user experience and
provide better performance. Hence, the decisionwasmade
toupgradeto thenewversionandreuseexistingdeveloped
modules.
ChangeManagementandUserEngagement
With a large-scale implementation catering to more than
3,000users,userengagement throughchangemanagement
was key to the success of the project. The team was able
to solicit feedback on eWorkplace quickly and improve the
systemdesignthroughthehelpofKnowledgeManagersand
AssistantDirectors(PlanningandControl)aschangeagents.
Walk-inclinics(insteadoftheusualclassroom-basedtraining)
wereconductedaftereWorkplacewentliveandservedasan
avenueforuserstorequestforassistanceorprovidefeedback
easily.
Itwasalso important topromote theuseof thesystem ina
funandinformalway.Quizzes,logodesigncompetitions,blog
articles, feedback sessions and various other engagement
campaigns were organised throughout the first year of
implementation. This encouraged users to discover more
about eWorkplace and familiarise themselves with its new
features.
GOING FORWARD
Since its implementation,eWorkplacehasachievedsuccess
as DSTA’s next-generation information work space. This is
evident fromthecontent thathasbeenaccumulated–more
than1,000teamsites,7,000wikipages,1.4milliondocuments,
46,000photosand25,000announcements.
eWorkplace implemented a secure and robust content
infrastructureandleveragedWeb2.0technologiestoachieve
thegoalofconnectingpeopletopeopleandpeopletocontent
via person-centric workspaces. These include a one-stop
personalised space, team spaceswithworkflows for simple
approvals and proper filing of project documents, and a
reorganised corporate Intranet based on the information
architectureandtaxonomydevelopedinPhase1.
are also displayed as query suggestions at the top of the
page.Staffcanfurtherrefinetheresultsbytogglingbetween
thedifferentsortoptionssuchas relevance,date (newestor
oldest),lifetimeviewsandrecentviews.
Crawlerswere also configured to look for entities (words or
phrases)within titles, headers,metadata and contentwithin
documents. Dictionaries can be created and deployed to
searchandstoretheseentitiesasmanagedpropertiesinthe
searchindexeswhichcanbeusedtocreatesearchrefinersfor
moregranularfiltering.
Visual improvements such as displaying an application
icon next to the title of search results and previewing of
documentcontentwhenacursorisplacedonasearchresult
is “highlighted”, also improved the speed inwhich staff can
locatecontentrelevanttothem.
CHALLENGES
ShorteningofITImplementationCycle
A typical IT implementation cycle in DSTA would require at
least18to24monthstodeliverthefirstmilestone.Theteam
was faced with the challenge of delivering key eWorkplace
capabilities in less than a year. The team’s strategy was to
tap an internal pool of resources to prioritise and proceed
with the system implementation for key collaboration and
engagementcapabilities.ThisalsoallowedDSTAtobuildup
and sharpen its competencies in KM technologies quickly.
Spiral developmentwas another strategy undertakenby the
teamtoshortentheprojectdeliverytime.Insteadofthetypical
waterfall model3 to deliver all capabilities in a ‘big bang’4
approach,theteamdeliveredeWorkplaceusingacommercial
off-the-shelf software with minimal customisations. This
helped to reduce the risk of implementation caused by
evolvingbusiness requirementsandallowedrequirements to
bevalidatedthroughaprototypingapproach.
Future-proofingAgainstTechnology
In themidstof theproject, the teamhadtodecidebetween
upgradingthesoftwaretothenextproductversion,whichwould
provideenhancedenterprisesocialcollaborationfeaturesand
in-memorycapabilities,orstayingwithapreviously released
version.
43DSTA HORIZONS | 2015
Figure3.ThefutureofeWorkplace
HIGHLY-CONTEXTUAL CONTENT
INTRICATELY-NETWORKED STAFF LIMITLESS PRODUCTIVITY
PEOPLE-TO-CONTENT
PEOPLE-TO-PEOPLE
NETWORKED-PEOPLE TO
INTELLIGENT WORKSPACE
“Building a robust content infrastructure”
“Constructing staff-centric workspaces”
Corporate Intranet
“Intelligently connecting people to achieve shared goals”
Project-focused Workspace
Community-driven Workspace
Personal Space Information Governance/Architecture
Contextual Search
Extensive Repository
Enterprise Social Network Analytics
External Collaboration
Focus for the next phase will be on the infrastructure,
processes and strategies needed to build social channels
for communication and collaborationwithin andbeyond the
organisation. Enterprise social technologies combined with
dataanalysisandmobiletechnologieswillconnectpeopleto
spottrendsandleveragetheknowledgeoftheorganisationto
completetasksrapidlyandsurfacepreviouslyhiddenpockets
ofvaluableinformation(seeFigure3).
ENDNOTES
1 Network separation refers to the initiative to secure the
organisation’s work environment by means of information
segregation.
2 DSTA-authored technical documents include trip and
studyreports,conferencepapers,post-gradthesesandcase
studies.
3 The waterfall model is an approach used in software
development.Itisasequentialdesignprocessthatcomprises
thephasesof Initiation,Design,Testing, Implementationand
Maintenance.
4 Big bang adoption is a software release method that
involvesgettingridoftheexistingsystemsandtransferringall
userstothenewsystemsimultaneously.
EWoRKPLACE:EVoLVINgDSTA’SKNoWLEDgEMANAgEMENTJouRNEy
44 DSTA HORIZONS | 2015
SOHYun Lin Jason is a Senior Engineer
(EnterpriseIT)fromtheBusinessInformation
Analytics and Database Services team.
He isresponsibleforthedevelopmentand
adoptionofsentimentanalysis,datamining
andvisualisation.Hewaspreviouslypartof
theEIT-DSTASystemsteaminvolvedinthe
supportofoperationsforeHabitatandops-
SupportNet,andtheireventual transformation intoeWorkplace.
JasonobtainedaBachelorofComputing (InformationSystems)
degree,withspecialisationinServiceScience,Managementand
Engineering,fromNuSin2011.
BIOGRAPHY
KOO Yih Liang Kevin is the current ops
Manager of eWorkplace in DSTA’s Chief
Informationoffice (CIo).He is responsible
fordrivingtheadoptionofeWorkplaceand
thecontinual improvementoftheplatform.
Hewasalsopartof theEnterprise IT (EIT)
teamthattransformedthehumanresource
IT landscape for the Ministry of Defence
and the Singapore Armed Forces. Kevin obtained a Bachelor
of Science (Electrical andComputer Engineering) degree and a
Master of Engineering (operations Research and Information
Engineering) degree from Cornell university, uSA, in 2002 and
2003respectively.
LIM Lay Har Evon is Assistant Director
(Planning and Control) from Enterprise
IT Programme Centre. She led a team
to implement eWorkplace and other
Knowledge Management (KM) projects in
DSTA to deliver the nextwave ofKMand
social enterprise capabilities. She was
previously involved in business development and planning as
well as in competency development programmes to drive the
development of SAP Enterprise Resource Planning capabilities
andcompetencybuildupwithinEnterpriseITProgrammeCentre.
EvonobtainedaBachelorofScience(ComputerandInformation
Sciences)degreefromtheNationaluniversityofSingapore(NuS)
andaMasterofTechnology (SoftwareEngineering)degree from
theInstituteofSystemsSciencein1999and2004respectively.
HO Wei Ling Angela is Head Design
Thinking(EnterpriseIT).Shewaspreviously
theopsManagerofeWorkplace inDSTA’s
CIo. She co-created DSTA’s KM vision
and strategic roadmap, and oversaw
the successful roll-out of eWorkplace.
A recipient of the DSTA overseas
undergraduate Scholarship, Angela graduated with a Bachelor
of Science (Computer Science) degree with Honours, with a
focus on Human-Computer Interaction from Carnegie Mellon
university,uSA,in2004.ShefurtherobtainedaMasterofScience
inTechnologyandPolicy,withafocusonAeronauticsandHuman
Factors,fromtheMassachusettsInstituteofTechnology,uSA,in
2006.
45DSTA HORIZONS | 2015
EWoRKPLACE:EVoLVINgDSTA’SKNoWLEDgEMANAgEMENTJouRNEy
46 DSTA HORIZONS | 2015
MoDEL-DRIVENARCHITECTuREAPPRoACHFoRENTERPRISESySTEMS
INTRODUCTION
The Model-driven Architecture (MDA) is a software design
approach defined by the object Management group
(oMg). TheoMg is an international, openmembership and
non-profit computer industry standards consortium that
developsenterpriseintegrationstandardsforawiderangeof
technologiesandindustries.
Modelsarekey toMDA inasoftwaredevelopmentprocess.
TheMDAapproachusesPlatform-IndependentModels(PIM)
whichincludebusinessprocessestodefinethefunctionalities
of a system. A strong foundation and institutionalisation of
Enterprise Architecture (EA) practice within the organisation
enforcesacommonmodelling language tocaptureallPIMs.
These PIMs are then translated and linked electronically
to Platform-Specific Models recognised by computers for
execution. This process of planning, design, development
and testing is termed theApplicationLifecycleManagement
(ALM). Tools that integrate across the ALM processes help
ensureclear traceability,controlofchangesandassessment
ofchangeimpact.
LAIKokKee,NGWendy,LOWKweeBoon
ABSTRACT
TheModel-drivenArchitecture(MDA)approachhasbeenrecognisedasamethodologythatcanhelpenhanceagilityandspeed in the implementationof enterprise IT systems. This article introduces the concept ofMDAandhow it helps inmanagingthecomplexitiesofintegrationandimprovingbusiness-ITalignment.IthighlightshowDSTAusesvariousMDAtechniquestoachieveaprocess-orientedsoftware implementationparadigm,wherebusinessrequirements (captured inprocessmodels)are linkedtoactual ITsystemconfigurationstoshorten implementationcycles.ThisarticlealsoshareshighlightsandlessonslearntintheMDAjourney.
Keywords:model-drivenarchitecture,softwaredevelopment,applicationlifecyclemanagement
DEFINING MODEL-DRIVEN ARCHITECTURE AND APPLICATION LIFECYCLE MANAGEMENT
Model-drivenArchitecture
InDSTA’scontext,MDAisdefinedasanapproachtoorganise
andmanagebusinessrequirementsinPIMs,whereautomated
tools can be reused for design and implementation into
IT systems. The principle is to separate the specification of
functionalityfromthatofimplementation.
Thisapproachleveragesthestrongfoundationandmaturityof
EApractice.Since2006,EAhasbeenadoptedasameansto
strengthenbusiness-ITintegrationinDSTA.TheEAframework
was developed to ensure that business requirements
(operationalview)andITimplementation(systemandtechnical
views)arereflectedaccurately inanarchitecturalmodel (see
Figure1).
TheMDAapproachentailstwospiralsofEAdevelopment(see
Figure2).Thefirst isat thebusinessparadigmlevel (what is
modelledversuswhat isbuilt). It isabout re-engineering the
47DSTA HORIZONS | 2015
businessparadigmintoprocess-orientedmodelsaccordingto
EAstandards.Thekeybenefitofthisstandardisedapproach
isthatfinalbusinessmodelswillbesignificantlysimplerand
refined, yet functionally richer than traditionalmethods. The
secondisattheITparadigmlevel (what isbuiltversuswhat
is used). It is about enabling the re-usability of business
models for design and implementation into IT systemswith
appropriate toolsandservices.This integrationenforces the
mappingofrequirementscapturedinthebusinessmodelonto
actual implementation.Withsuchconsistency, thealignment
betweenbusinessandITisalsoenhanced.
The MDA concept also allows process implementations,
systemconfigurationsaswellastestscenariostobegenerated
automatically through business models. Through early
Figure1.EAview
Specifies
system
capabili/es
required to
sa/sfy
informa/on
exchange
System View (SV)
Relates systems to Operational views
Operational View (OV)
Identifies what needs to be accomplished and
who does it
Technical View (TV)
Prescribes standards and conventions
Figure2.ConsistencythroughanMDAapproach
Models Business Process Models
Logis1c + Finance + Human Resource
What is Modelled
What is Built
What is Used
prototyping and better communication across stakeholders,
issues and conflicts are reduced during implementation.
overall, systemdevelopmenteffort and timeare reducedas
compared to conventional systems development methods.
This enhances the pace and agility of how systems are
designed, built and tested in the application lifecycle of the
system.
ApplicationLifecycleManagement
ALM facilitates the coordination between the business
and development teams (see Figure 3). This includes the
managementofrequirements,building,testinganddeployment
sothatapplicationscanbemanagedeffectivelythroughoutthe
applicationlifecycle.
48 DSTA HORIZONS | 2015
ThemainstagesofALMareasfollows:
a) Requirements –The requirements foranewapplication
are gathered and expressed as business processes, events
andactionstakenbyvariousstakeholders.
b) Design – The requirements are translated into
specificationsfortheITcomponents.Theyincludethedesign
of the application or any customisation to the standard
packagedsoftwareaswellasthedesignoftheenvironmentor
operationalmodelthattheapplicationhastorunon.
c) Build – Both the application and the operational model
aremadereadyfordeployment.Applicationcomponentsare
codedoracquired,andthenintegratedandtested.Foroff-the-
shelfsoftware,requiredcustomisationswillbedoneduringthis
phase.
d) Deploy – Both the operational model and applications
are moved from the development environment to a test
environment, and finally to the production environment.
Applica'on Lifecycle Management Phases:
Requirements Design Build & Test Deploy
Business Business Process
Expert Development
Team
Figure3.ALM
Requirements
Design
Build and Test
Deploy
Operate
Op7mise
Discover and Evaluate Business Func3on Predic3on
Prepara3on and Blueprint
Landscape Verifica3on Iden3fy Technical Usages Maintenance Op3miser
Realisa3on – Install, Ac3vate
Installa3on Switch Framework Configura3on + Customisa3on Predefined Test Content
APPLICATION LIFECYCLE
MANAGEMENT
Figure4.ALMphases
The operational model is incorporated into the existing IT
environment and the application is installed on top of the
operational model. This is also typically governed through
a release and deployment management process to ensure
properconfigurationcontrol.
e) Operate – The IT services organisation operates the
applicationaspartofthedeliveryofaservicerequiredbythe
business.Theperformanceoftheapplicationinrelationtothe
overallservice ismeasuredcontinuallyagainstservice levels
andkeybusinessdrivers.
f) Optimise – The results of the service level performance
measurements are measured, analysed and acted upon.
Possible improvements are discussed and developments
initiatedifnecessary.Thetwomainstrategiesinthisphaseare
tomaintainorimproveservicelevelsandlowercost.
The key phases and the stakeholders involved in ALM are
illustratedinFigure4.
49DSTA HORIZONS | 2015
THE EVOLUTION OF MDA
MDA grew in sophistication with the maturity of EA, tools
andpeople.Itisusedto:harmoniseprocessestofacilitateIT
implementation, transform business processes, and drive IT
implementation.
MDAtoHarmoniseProcessesandFacilitateITImplementation
The MDA approach is largely driven by the successful
implementationoftheEnterpriseSystem(ES)intransforming
the logisticsandfinanceoperationsof theSingaporeArmed
Forces(SAF).
Initiated in 2003, the ESwas the first large-scale system in
whichbusinessprocessmodelsweredevelopedextensively
toanalyseandestablishbusinessrequirements.Theapproach
proved crucial in facilitating the analysis, harmonisation and
integration of the diverse business processes found in the
differentservicesandLinesofBusiness(LoB).Withoutthese
business models, it would have been extremely difficult to
visualise and understand the complexity of the business
operations. In all, theproject harmonisedand standardised
more than 90% of some 600 processes defined across the
Singapore Army, the Republic of Singapore Navy (RSN),
the Republic of Singapore Air Force (RSAF), Joint and the
Ministry of Defence (MINDEF). Based on these business
process blueprints, ES(Logs) was implemented in phases
startingwiththeRSNin2005,theSingaporeArmyandJoint
in2006,followedbytheRSAFin2007–allontimeandwithin
budget. The ability to reuse processes also resulted in cost
savings of some S$80million in systems implementation. It
alsotransformedthewaylogisticsandfinancialoperationsare
carriedouttoday(Lim,Ham,Heng,&Koh,2010).
Thiseffortwasextendedtothedomainsofplatforms,buildings
and infrastructure,medical logistics, IT andR&D, leading to
furtherbenefits.
MDAtoTransformBusinessProcesses
The Business Process Management (BPM) Department
under the MINDEF Chief Information office was set up in
February2008tofacilitateanddrivebusinesstransformation.
Inadditiontoworkingwithbusinessownerstoleadbusiness
transformationprojects,itisalsoresponsibleforbuildingupthe
DefenceBusinessMap1andfacilitatingenterpriseintegration.
The business transformation initiative is an enterprise-wide
effort. For it to succeed, strong commitment and support
from senior leadership is crucial. The existing IT steering
committee,chairedbyseniormanagementfromMINDEFand
theSAF,extended its termsof referenceto includebusiness
transformation initiatives. The steering committee, together
with LoB leaders, provide overall leadership in transforming
business capabilities. It reviews and endorses business
transformation proposals, and also plays the critical role of
identifyingandresolvingownershipissuesforbusinessareas
whereclearownershipislacking(Limetal.,2010).
A four-phase Integrated Methodology for Business
Transformation was also established and practised. This
approach starts off with the prioritisation and selection of
business functions for process mapping, followed by the
developmentoftargetbusinessarchitecture,andsubsequently
the development of the conceptual solution. The last phase
involvesimplementationofthesolution.
usingthisapproach,variousbusinessprocesstransformation
projects have since been successfully implemented with
enhancedcapabilitiesacrossthemanagementofareassuch
ashumanresource,buildingandinfrastructure,transportand
ammunition.
MDAtoDriveITDevelopment
Withthematurityofapplicationsinthemarket,itisnowpossible
to translate requirements frommodels intoapplications (see
Figure5).ThetrendofadoptingMDAtodriveITdevelopment
hasbeenconsistentacrossotherdefenceagenciesfromother
nationsaswell.
For commercial off-the-shelf (CoTS) products such as the
SAP2EnterpriseResourcePlanning (ERP)System, theMDA
approach leverages theALM functionofSAP,wheremodels
aresynchronisedintoaSAPapplicationlifecyclemanagement
toolforapplicationdevelopment.
Forcustomisednon-CoTSsystems,theMDAapproachutilises
BPMSuite(BPMS)totranslatebusinessprocessmodelsinto
executableapplications.
MoDEL-DRIVENARCHITECTuREAPPRoACHFoRENTERPRISESySTEMS
50 DSTA HORIZONS | 2015
ThethreekeyareasofMDAimplementationareasfollows:
Model-driven Documentation and Development
DSTAhastakenona leadershiprole in thetechnicalareaof
EA to ensure architectural alignment and sound technology
implementation. In 2008, DSTA successfully delivered a
central repository of businessmodels called AVATAR3 using
the Architecture of Integrated Information Systems (ARIS)
platform.Thesemodelswerecreated inaccordancewithEA
modellingstandardsdefinedbyaDSTAteam.
Inearly2011,aproof-of-conceptwasconductedtoascertain
that the existing business process models captured in
AVATAR could be synchronised with SAP SolutionManager
(SAP SolMan). The synchronisation mechanism was tested
to work both ways. First, business requirements defined
as process models in AVATAR should be transferred and
translated automatically to SAP systems so that developers
canbeginconfiguration.Second,SAPreferencemodelsand
implementationinSAPSolManshouldalsobeimportedback
intoARIStoolstojump-startorupdatethebuild-upofunique
businessrequirementsinAVATAR.Thiswouldhelptoreduce
thedevelopmentleadtimeandallowchangestobemanaged
properly.
Figure5.MDAtodriveITdevelopment
Model-driven Testing
Extensivetestingisrequiredforeverypieceofsoftwareduring
the various phases of software development. The scope of
testing usually involves conducting some form of change
impact analysis which requires a good knowledge of the
business,softwarearchitectureanddesigndetails.
Model-driven testing is a new and promising approach for
software testing as it reduces effort and turn-around time
significantly. It enables efficient test scope planning by
accurately identifying the affected business models due to
changes introduced. This is made possible because of the
betterbusiness-ITalignmentoftheMDAapproach.
Withbusinessprocessesdocumentedintheformofbusiness
processmodels,softwaredevelopmentteamscannowmake
useofthesemodelstocreatetestcasesbasedonstructured
scenarios.Eachtestscriptproposedwillcorrespondtoagiven
scenario,thusenablingeasytrackingandverification.Thisnew
methodology and toolset was pioneered in the Centralised
Corporate Services (CCS) BPMS project and has proven to
reducethetimetorolloutnewapplications,whilemaintaining
highstandardsinsoftwarequality.
Business Model
Synchronisation and generation of system
configuration specifications
Model-‐Driven Development
Generation of business Process documents
Model-‐Driven Documenta3on
Generation of business scenarios for testing
Model-‐Driven Tes3ng
Analysis of business process performance
Process Intelligence and Performance Monitoring
51DSTA HORIZONS | 2015
Process Intelligence
CCS comprises a suite of services in the areas of human
resource, corporate finance and budgeting, logistics and
procurement and IT support. The aim of CCS is to bring
together common corporate functions performed across
entities to create synergies and leverage the competencies
of respective professional agencies for greater efficiency.
Theintentisalsotoautomateasignificantnumberofmanual
processessuchasassetstocktakingandcondemnation.
To help CCS overcome the need to automate manual
processes, DSTA piloted a BPMS tool that enables timely
andaccuratemonitoringandanalysisofbusinessprocesses,
thus enhancing efforts in streamlining, tuning and exception
handling. The BPMS platform also serves as a common
workflow tool to integrate existing disparate processes and
reducemanualprocesshand-offs.
usingtheMDAapproach,theBPMStoolwasabletoaccept
existing business processes already mapped out under the
EA framework and translate them into executable business
workflows with minimum development effort. This helped
to reduce the implementation lead time for ITsystemswhile
meetingbusinessrequirements.
CHALLENGES
Although the MDA approach is still at its infancy, several
challengeshavebeenencounteredsofar.
PracticalityofaSingleModellingStandard
TheMDAapproachwaspiloted inthe implementationofthe
EnterpriseSystemandCCSBPMS.Forbothplatforms,there
were significant efforts to ensure that the models captured
in AVATAR were usable by SAP and BPMS for subsequent
application development. Through the pilot tests, it was
concludedthatasingleprescribedEAstandardandmodelling
toolmaynotbeable tomeetbothSAPandBPMSplatform
specific requirements. Hence, a hybrid model will have to
be developed to better meet the needs of both CoTS and
bespokedevelopments.
IndustryCompetencyandReadiness
When the MDA approach is fully operationalised, all
IT implementations will need to comply with the MDA
requirements. This means that System Integrators (SI)
undertakinganyprojectimplementationwillneedtohavethe
necessarycompetencyinMDA.AstheadoptionoftheMDA
approachisstillnewintheITindustry,thismayposeariskto
the projects’ timeline and cost.DSTAhas taken a proactive
approachtoaddressthisbyprovidingthenecessarytraining
and guidance on the MDA approach to SIs engaged in IT
projects.ThecompetenciestotakeontheMDAapproachis
alsoexpectedtomatureasmoresoftwarefirmsandSIsadopt
theMDAapproachacrosstheITindustry.
MOVING FORWARD
ThefirstphaseadoptionofMDAhasmetits intendedgoals.
The next phase will be to proliferate the practice across
CorporateIT(CIT)systemsprogressively.Todothis,thecurrent
MDAapproachwillbereviewedinordertobemoreeffective
andefficientincateringtodifferenttypesofITsystems.
The focus will also be centred on further enhancing the
integrationofAVATARwithSAPERPapplications.Thiscould
be achieved through further automation of themanagement
oftheapplicationlifecycle,aswellastheenhancementtothe
qualityofexistingmodelscapturedwithinAVATAR.
Beyond the objectives of achieving business agility and
shorteningthedurationfromapplicationdevelopmenttoroll-
out,theMDAapproachalsoensuresbusinesscontinuityinthe
eventthatthereisaneedtore-platformtheSAPERPsystem.
CONCLUSION
The concept of using the MDA approach to automate the
integration of business requirements captured in business
processmodels into actual application development is both
desirableandexciting forbusinessusersand IT teams.The
MDA approach has demonstrated the ability to reduce the
duration from application development to roll-out, for IT
systems through the use of models that drive application
development.
MoDEL-DRIVENARCHITECTuREAPPRoACHFoRENTERPRISESySTEMS
52 DSTA HORIZONS | 2015
REFERENCES
Lim,H.C., Ham,y. F., Heng,C.C. L., &Koh,C. y. (2010).
Driving Business Transformation through a Process-centric
Approach.DSTAHorizons,28-43.
objectManagementgroup.(n.d.).objectmanagementgroup
terms and acronyms. Retrieved from http://www.omg.org/
gettingstarted/save_terms_and_acronyms.htm.
ENDNOTES
1 The Defence Business Map illustrates the CIT lines of
business (such as finance management, human resource
management)andrespectivebusinesscapabilitiestosupport
the enterprise’s strategic outcomes and objectives. The
DefenceBusinessMapwillbefurthercolourcodedtoindicate
theIT-enablementstatusofeachbusinesscapabilitiesandfor
planningoffutureITenablement.
2 Systems Application and Product in Data processing,
or SAP, is an enterprise resource planning software which
comprises a number of fully integrated modules covering
virtuallyeveryaspectofbusinessmanagement.
3 AVATAR stands for “The Actionable, CollaboratiVe and
AlignedEnTerpriseArchitectureRepository”.
BIOGRAPHY
LAI Kok Kee is a System Manager
(Enterprise IT) who currently oversees the
operations and support management of
enterprise SAP systems. Kok Kee is also
a SAP Certified Technology Consultant.
He graduated with a Bachelor of Science
(Information Systems) degree from the
ThamesValleyuniversityofLondon,uK,in
2003.
NG Wendy is a Principal Engineer
(Enterprise IT) who is currently involved
in realising the Model-driven Architecture
infrastructure through the implementation
of SAP Application Lifecycle Management
(ALM)fortheMinistryofDefence(MINDEF)
Enterprise Systems(Logs). She was
previously involved in the development
of Corporate IT’s Enterprise Architecture for MINDEF and
the Singapore Armed Forces (SAF). Wendy is a certified SAP
consultant inSAPapplications and a TogAF (Theopengroup
Architecture Framework) Certified Enterprise Architecture
Practitioner. She graduated with a Bachelor of Science in
(ComputerandInformationSciences)degreewithMeritfromthe
NationaluniversityofSingapore(NuS)in1998.
LOW Kwee Boon is a Senior Systems
Architect(EnterpriseIT).SincejoiningDSTA
in2000,hehasbeeninvolvedinvariousSAP
implementation projects for MINDEF and
the SAF in areas ranging from functional,
technical tocross-applicationmodules.He
is well versed in the latest development
andevolutionoftechnologiesintheareaof
EnterpriseResourcePlanning.Hehaschartedoutstrategiesand
implementation roadmaps in areas includinggovernance,Risk
andComplianceaswellasALMforMINDEFandtheSAF.Kwee
Boon isalsoacertifiedSAPconsultant inSAPapplications.He
graduatedwithaBachelorofEngineering(MechanicalEngineering)
degreewithFirstClassHonoursfromNuSin1997.
53DSTA HORIZONS | 2015
MoDEL-DRIVENARCHITECTuREAPPRoACHFoRENTERPRISESySTEMS
54 DSTA HORIZONS | 2015
DATAANALyTICSFoRoPTIMISINgCyBERANDDATACENTREoPERATIoNS
INTRODUCTION
Data analytics is about deriving insights fromdata. Through
mathematical, statistical and machine learning methods,
patternscanbediscovered topresentbusinessesandother
operationswithamorerelatableviewoftheirdatafordecision
making.
DSTA implements data analytics for theMinistry of Defence
(MINDEF)inanumberofareas.Intheairandmaritimedomains,
analyticsisusedtoaugmentsituationalawarenesswithreal-
time interpretation of movement patterns and detection of
anomalous activity. Analytics is also applied in a variety of
Enterprise IT areas such as finance, procurement, logistics
and human resource. The rich data sets accumulated over
extendedperiodsofoperationareanalysedtoprovidesupport
inareaslikebudgetoptimisation,frauddetection,supplyrisk
managementandstaffengagement.
CHANGXuquanStanley,SIMSzeLiang,WONGMingQian
ABSTRACT
Awealthofdata isgeneratedby theMinistryofDefence’s ITnetworkswhichcanbeanalysed to improvecyber threatdetectionanddatacentreoperations.
Incyberdefence,detectionalgorithmshaveadvancedfromstaticrulestomachine-learningalgorithmsthatcanharnesstherichamountofnetworkdataavailabletodetectlowsignatureanomaliesintheenvironment.Similarly,statisticalanalysisoninfrastructurelogscanderivepatternsinsystemutilisationanduserbehaviourtogaininsightsintoincreasinglycomplexoperatingenvironments,pre-emptincidentsandoptimiseresourceallocation.
ThisarticleshareshowDSTAappliesdataanalytics toenhanceefficiencyandeffectiveness incyberdefenceanddatacentreoperations.
Keywords:dataanalytics,cyberdefence,datacentre,IToperationsanalytics
This article describes how DSTA uses data analytics in the
appliedareasofcyberdefenceanddatacentreoperations.
DATA ANALYTICS IN CYBER AND DATA CENTRE OPERATIONS
Cyber defence and data centre operations are becoming
increasingly challenging to manage due to: (a) increasing
criticality of IT; (b) growth in complexity and number of
systems;and(c)increasinglysophisticatedcyberadversaries
andthreats.
Traditionalincidentandeventmanagementtoolshaveserved
adequately in the detection, notification and reporting of
events.However,theyneedtobecalibratedmanuallytodetect
anomaliesandtoanalysecorrelatedeventsandtrends.
55DSTA HORIZONS | 2015
Dataanalyticscanbeimplementedtoautomatethederivation
ofsuchinsights.Itscapabilitiesincludeadvancedsearchand
indexingtechniquesthatalloweffectivecorrelationofevents
andanalysisofstatisticalpatterns.Machinelearningmethods
are also applied to discover topological relationships and
establishbehaviouralbaselines.
Assuch,theexistingwealthofdatacanbemined.Thedata
made available for analytics are: (a) machine data such as
utilisation and activity logs from servers and networked
devices;(b)networkdata;and(c)syntheticdata,whichisdata
generatedbyprobingthesystemwithsimulatedtestcases.
The application of these data in cyber defence and data
centreoperationscanbecategorisedinto:anomalydetection,
discoveryofhiddenpatternsandinsights,andoptimisationof
resources.
AnomalyDetection
Statistical andmachine learningmethods are used to trend
and forecast system utilisation and behavioural patterns
continuously,andbuildbaselinesthatalsoenablethedetection
oflow-signatureanomalieswithhighfidelity.
Bycorrelatingsuchanomaliesacrosssystemconfigurations,
compliancechecksandsecurityevents,preventivemeasures
can be taken to avert the potential onset of performance
degradationorhalttheprogressofcyberattacks.Theusage
of analytics thus reduces the reliance on tacit knowledge
and individual competencies to identify risks, and construct
an action planwhichwould be unsustainable in the face of
growingsystemcomplexitiesandmanpowerconstraints.
Systemutilisationandwebaccesspatternsarealsocorrelated
tounderstand,andsubsequentlyanticipatetheimpactofuser
activitieson theperformanceofapplications.These insights
allow data centre operations to prepare for planned user
activities effectively or determine the possible causes of an
unplannedsurgeinutilisation.
Anomalies can also be indicative of new exploits or freshly
compromised assets in the networks that warrant further
investigationby incident response teams.Examplesof such
anomalouseventsincludereconnaissanceactivitiesbyexternal
entitieswhoareattemptingtogaininsightsintothenetwork,
and computers infected with viruses that are attempting to
performunauthorisedactions.
Machine learning algorithms, both supervised and
unsupervised, are also being applied to pick up events that
exhibit similar behaviours from past anomalous events or
deviations. Supervised learning algorithms are used to pick
updomainnameresolution requests tosuspiciousdomains.
unsupervisedlearningalgorithmssuchask-meansclustering
areusedtocategorisenetworkandmachinedatainto“normal”
and“anomalous”clusters.Thesemachinelearningalgorithms
are commonly used in the cyber domain, especially in the
detectionofnewthreatsasthere isnoknowninformationof
thethreatthatcanbeusedtoidentifyitwithcertainty.
Alternatively,knownabnormalbehaviourscanalsobeusedin
analyticsto facilitatethecategorisationofobservedpatterns
into“normal”and“anomalous”groupsbasedonthepatterns’
similarities toknownattributesofabnormalbehaviours.This
approachcanbeusedtosupplementanomalydetectioninthe
initialphaseofdefiningthebaselineoftheenvironment,where
either insufficienttimehas lapsedtobuildareliablebaseline
orwhereitisundesirabletoassumethatlearnedbehaviouris
normalbydefault.
DiscoveryofHiddenPatternsandInsights
Advanced analytics algorithms are used for indexing,
searchingandcorrelating largedatasets todiscoverhidden
patterns, relationshipsand insights thatarenormallydifficult
forahumantoperceive.
one such example is the analysis of time intervals between
Internetrequestsoriginatingfrommachineswithinthenetworks.
Malwareoftenneedstocontactitscommandandcontrol(C2)
serverson the Internet to receive further instructions.These
requests usually occur in very regular intervals as they are
controlledbyaprogramme.Thisregularpatternisillustratedin
Figure1.Bycomparison,human-initiatedwebsurfingrequests
arerandomwithirregularintervalsbetweenrequestsasshown
in Figure 2. The standard deviation and entropy between
the differences in the time intervals are calculated, and low
standarddeviationsandentropyvaluesgive indications that
theserequestsareoccurringinaperiodicmanner.usingthis
analysis,machinesinfectedwithmalwarethatwerecontacting
C2serversperiodicallyhavebeendetectedinthepast.
56 DSTA HORIZONS | 2015
Analytics algorithms are also used to identify cyber attack
campaignsbyanalysingtheirintrusionindicators,suchasthe
sourceoftheattacksandmalwareused,againstanintrusion
attributes database. Hutchins, Cloppert, and Amin (2011)
defined a kill chainmodel1 to describe the intrusionphases
of a cyber attack and identify indicators that link individual
attacks to a campaign. using information derived from the
analysis,cyberdefenceteamscanalsodeterminethetactics,
techniques and procedures (TTP) of the attackers, allowing
themtostayaheadoftheattacks.
Fordatacentreoperations,advancedsearchingandindexing
capabilities are used to perform root cause analysis for
incidents.Thisisacriticalyettime-consumingactivityduring
theresolutionofincidents.Acommonproblemisthedifficulty
indeterminingtherootcauseeventamongaclusterofevents
thatfollowafterit.
For example, the failure of a common email gatewaywould
eventually result in transactional failures being reported by
most applications that serve user workflows. That would
generateonealert foreachapplicationservice foreachtime
itattempts tosendanemail.Amongallof thosealerts,only
onealertwouldhavebeengeneratedfortherootcause.Data
Figure1.Regularnetworktrafficpatternsofmalwarebeaconing
Figure2.Irregularnetworktrafficpatternofwebsurfingbehaviour
analysiscouldbeusedtoestablishsimilaritiesintime,volume
and textual patterns between alerts, thus removing large
amountsofnoiseandmaking iteasierto identifyanomalous
events that are unique to the time period leading up to the
incident.
Analytics is also being used to discover new relationships
between events. For example, an application error and a
shortageof disk spacemaybe considered as two separate
events that are resolved independently. yet, the shortage of
diskspacemayhavebeencausedbyapplicationerrorswhich
generatelargeamountsoflogswithinashortperiodoftime.
Analytics is being applied to discover such correlations and
causalrelationships,improvingbothassessmentandreaction
toevents.
OptimisationofResources
Analytics has become more pertinent in optimising data
centre resources in recent years. This can be attributed to
the increasing use of virtualisation technologies that enable
resourcesharingandlivemigrationofworkload.
57DSTA HORIZONS | 2015
Within the data centre, a requirement placed on server
virtualisationandstorageplatformsistoprovidetheanalytics
andautomationrequiredtoredistributeworkloaddynamically
for optimal system resource usage. This also enables the
overall distribution of virtualised application servers to
adapt constantly to changes in utilisation patterns and find
placementonphysicalserversthatcanbestservetheirneeds.
Fordatastorage,analyticsidentifiesfrequentlyaccesseddata
continuouslyforplacementonstorageresourceswhereitcan
beservedwiththebestthroughput.
Analytics also supports “right-sizing” by utilising historical
and projected patterns to anticipate the correct quantities
of resource allocation, enable reclamation and redistribution
of resources to copewith short-term surges, andmoderate
changes in demand by optimising resources within existing
capacity.
Beyondshort-termoptimisations,predictiveanalytics isalso
used tomodel the impact that projected requirementsmay
haveonexistingcapacityandanticipategrowthrequirements.
Duringthisanalysis,availabilityandperformancerequirements
are considered alongside anticipated changes in resource
demands as a result of the utilisation and growth patterns
of existing deployments. With the inclusion of planned
deploymentswithinthecapacityplanningmodel,anyresulting
shortageincapacityandtimeframecanguidethepreciseand
timelyacquisitionsofadditionalcapacity.
CHALLENGES
The following points present challenges that need to be
addressedinordertorealisethepotentialofanalyticsforcyber
defenceanddatacentreoperations.
DerivingRelevantInsights
Before analytics can be implemented, a problem statement
has to be defined to determine the appropriate data and
methods to use. It is usually not straightforward to frame a
problem statement for analysis. For example, questions
like “how to reduce operating costs” or “which servers are
infectedwithmalware”arenaturalquestionsthatarisebutare
toogeneric to initiate immediateanalysis.Apart fromhaving
familiaritywiththecontextofthequestion,framingaproblem
statementrequiresstafftobetechnicallyproficientindiverse
domains such as IT infrastructure, cybersecurity, statistics
and mathematics in order to identify suitable metrics and
methodsthatcanderivetherequiredinsights.Acquiringsuch
competenciesrequiresanorganisationalcommitmentoftime
andresources.
Inpractice,whereadesiredinsightisframedatalevelthatis
tooobscureto initiateanalysis,a thoughtprocesstoreduce
theoriginalquestion recursively intosmaller intrinsicqueries
helpstomaketherelevantdataandapproachmoreapparent.
ReliabilityofAnalyticResults
The reliability of both descriptive and predictive analysis
remainsfundamentaltotheeffectiveuseofanalytics.Indata
centreoperationswheretheproblemismoredefined,numerous
analyticaltoolsareavailableinthemarketwhichprovidenon-
traditionalmeans to collect relevant data and analyse them
forcommonly required insights.Thisnecessitatesevaluation
of the results produced by these products aside from their
technicalspecificationsorcapability.However, thechallenge
liesinvalidatingtheaccuracyoftheseresults.
In practice, the validation of descriptive analytics results
is straightforward as in the case of incident resolution and
avoidance, as erroneous analysis is usually obvious and
remediable on hindsight. However, in the case of predictive
analyticssuchasresourceoptimisationorcapacityplanning,
analytics recommendations are used to serve as inputs to
thetraditionalplanningprocessforaperiodoftimebefore it
maybedeemedsufficiently reliable to replacethe traditional
processitself.
CONCLUSION
Thisarticlehashighlightedsomewayswhichdataanalyticsis
used tooptimisecyberdefenceanddatacentreoperations.
Dataanalyticsisasignificantgame-changerthatallowsmore
effective application of insights. From the strengthening of
securityposturetoenhancementofuserexperience,atangible
impacthasbeenmadeonMINDEF’snetworks.
Dataanalyticshasalsoresultedinlessdowntimeduetobetter
predictivecapabilities,while improved insightshaveenabled
swifterandmoreeffectiveactionsagainstcyber threatsand
serviceoutages.
In addition, data analytics augments the optimisation of
resourceallocation indatacentreoperations, enabling rapid
applicationdeliveryinamorecost–effectiveapproach.
DATAANALyTICSFoRoPTIMISINgCyBERANDDATACENTREoPERATIoNS
58 DSTA HORIZONS | 2015
Tostayaheadofsophisticatedcyberattacks,dataanalytics
has become an important tool to pick up hidden indicators
of these threats. As hackers come up with new TTPs, new
measureshavetobedevelopedandthisismadepossibleby
thevaluableinsightsgainedfromanalytics.
Together, a more secure yet effective IT experience can be
deliveredtoMINDEFwhileincurringlesseffortandpotentially
loweroperatingcoststhroughtheuseofdataanalytics.
REFERENCES
Dua,S.,&Du,x.(2014).Dataminingandmachinelearningin
cybersecurity.CRCPress:BocaRaton,FL.
Hutchins, E. M., Cloppert, M. J., & Amin, R. M. (2011).
Intelligence-driven computer network defense informed by
analysisofadversarycampaignsand intrusionkill chains. In
J.,Ryan(Ed.),Leadingissuesininformationwarfare&security
research (pp. 78 – 104). Reading, uK: Academic Publishing
InternationalLtd.
Jacobs,J.,&Rudis,B. (2014).Data-drivensecurity:analysis,
visualizationanddashboards.JohnWiley&Sons:Indianapolis,
IN.
Münz, g., Li, S., & Carle, g. (2007, September). Traffic
anomalydetectionusingk-meansclustering.Proceedingsof
Leistungs-, Zuverlässigkeits- und Verlässlichkeitsbewertung
von Kommunikationsnetzen und Verteilten Systemen, 4. gI/
ITg-WorkshopMMBnet2007,Hamburg,germany.
Singhal, A. (2007). Data warehousing and data mining
techniquesforcybersecurity.Springer:Newyork.
ENDNOTES
1 Akillchainisasystematicsequenceofeventsperformed
by an adversary to select and engage a target to achieve
a desired effect. In describing a cyber attack, Hutchin,
CloppertandAmindefinedthekillchainassevenphasesof
activity comprising: (a) reconnaissance to select the target;
(b) weaponisation of the attack payload; (c) delivery of the
payload;(d)exploitationofthetarget;(e)installationoftrojanor
backdoorintothetarget;(f)establishingcommandandcontrol
channel tocontrol thetarget;and (g)executionofactionsto
achieveobjectives.
BIOGRAPHY
CHANG Xuquan Stanley is a Manager
(Cybersecurity)workingonthedevelopment
and application of analytics for cyber
threat detection. Stanley graduated with
a Bachelor of Engineering (Computer
Engineering) degree with First Class
Honours from the National university
of Singapore (NuS) in 2006. He further
obtainedaMasterofScience(DefenceTechnologyandSystems)
degreefromTemasekDefenceSystemsInstitute in2010aswell
as a Master of Science (Computer Science) degree from the
NavalPostgraduateSchool,uSA,in2011.
SIM Sze Liang is a Manager (InfoComm
Infrastructure) overseeing data centre
virtualisation and private cloud computing
initiatives for the Ministry of Defence’s
(MINDEF)Corporate IT (CIT) infrastructure.
Sze Liang has also been actively involved
inthemodernisationofITinfrastructureand
leading implementations for infrastructure
consolidation and system automation. In
addition,heisexploringtheuseofanalyticstoaugmentincident
managementandcapacityplanning forvirtualised infrastructure.
Sze Liang graduatedwith aBachelor of Engineering (Computer
Engineering)degreewithHonoursfromNuSin2009.
WONG Ming Qian is a Senior Engineer
(InfoComm Infrastructure) managing
and implementing analytics capabilities
across MINDEF’s CIT infrastructure. He
is also involved in the enhancement of
existing analytics dashboards to improve
functionalityandusabilityofanalyticaltools
and systems.MingQian graduatedwith a
BachelorofComputing(ComputingScience)degreefromNuSin
2006.
59DSTA HORIZONS | 2015
DATAANALyTICSFoRoPTIMISINgCyBERANDDATACENTREoPERATIoNS
60 DSTA HORIZONS | 2015
CHALLENgESANDDESIgNCoNSIDERATIoNSFoRRADARoPERATIoNINLoCALLITToRAL
INTRODUCTION
The Naval Doctrine of the uS Navy (2010) defines a littoral
regionastheportionof theworld’s landmassesadjacentto
theoceanswithindirectcontrolofandvulnerabletothestriking
power of sea-based forces. Singapore, being one of the
busiestportsintheworld,issurroundedbybusyandnarrow
water passages, where large numbers of vessels of varying
sizes pass through. This results in a very complex littoral
environmentfor localradaroperations,posingamultitudeof
uniquechallenges for radarsystemsto track targetsquickly,
accurately and reliably. Hence, it is important that these
challengesare identifiedand tackled throughupfrontdesign
considerations,iterativesystemtestingandoptimisation.
Thisarticlepresentsthechallengesfacedandtheconsiderations
involvedindesigningaradarforoperationinthelocallittoral
environment.Thefirstsectionofthearticledescribesthekey
characteristicsof the local littoral environmentandhow it is
differentfromanopensea.Thisisfollowedbyanoverviewof
actualobservationsfromlocalradartrialsanddemonstrations.
LOManLing,LOKEMunKwong
ABSTRACT
Due to Singapore’s geographical locality, its naval and airborne maritime surveillance radars operate in a uniquelittoral environment that poses a plethora of challenges to their system design. This article briefly describes thesechallenges, and focuses on relating experiences gained from operationalising radars that perform well in thelocalenvironment.Theseexperiencesincludethestringentprocessoffocusingonthesystemarchitecturedesignduringthe front-end definition phase, simulation and testingwith environmental data during the development phase, and theeventual fine-tuning andoptimisationphase through trials.With advancements in technology, this article alsoprovidesanoverviewofpromisingadvancedradardevelopmentsandtheexpectedbenefitsinthefuture.
Keywords:radar,littoral,surveillance
Next, thearticlepresentsbestpracticesof radardesignand
testingdevelopedfromtheseexperiencestomakethesystems
morerobustforlittoralsurveillance.Finally,itconcludeswitha
glimpseofpromisingtechnologieswhichhavethepotentialto
improveradarperformanceinthelocalenvironment.
OPERATIONAL ENVIRONMENT
Whendesigningandevaluatingasensorsystem,athorough
understanding of the chief design drivers – mission profile,
area of operation and targets of interest – is essential. This
is especially critical in a complex littoral environmentwhere
thereisalargevarietyanddensityoftargetsunderanomalous
propagation effects, multipath and radio frequency (RF)
interferences.Figure1showsasatelliteimageofthecongested
Singaporeharbour.
61DSTA HORIZONS | 2015
UrbanCoastlineandNarrowPassageways
In the open sea, target returns are large compared to
background sea and weather clutter. As such, sufficient
target strength for detection can be accomplished easily to
obtainagoodsurveillancepicture.on thecontrary, a target
hastocompetewithlandclutterandmanyothertargetsina
littoralenvironment.According to theuSEnergy Information
Administration (2014), the Strait of Malacca is one of the
world’smostsignificanttrafficchokepoints,withthePhillips
Channelnarrowingdownto1.7mileswideclosetothesouth
of Singapore. This is exacerbated by coastlines lined with
buildings and man-made structures which typically have
strong radar reflections. In addition, the presence of targets
at close proximity decreases the amount of reaction time
available. This implies a heavier demandon the radar tobe
reliableintargetdetectionandextraction.
DiversityofTargets
Due to the proximity to land, radars operating in a littoral
environmentalsoneedtocopewithagreatervarietyoftargets
whichcanbeairborne,surfaceorpop-uptargetsfromnearby
landareas.Examplesincludesmallfastcraft,helicopters,low
flyingunmannedaerialvehiclesandsubmarineperiscopes,all
ofwhichpossessverydisparatekinematicsandphysicaltraits
and are used for different missions. Figure 2 illustrates this
diversitybasedon typicalRadarCrossSection (RCS)values
andvelocitiesatmicrowavefrequencies(Skolnik,2002).
LocalPropagationConditions
Chia, Khan and Chou (1988) highlighted that the equatorial
locationofSingapore results inanabsenceofstrongstorms
and typhoons.Thewindspeeds inandoutofSingaporeare
atalowaverageofabout10knots,leadingtocalmconditions
in the surroundingwaters. The low sea states translate into
reflectiveseasurfaces,whichcouldresultinmultipatheffects.
Another propagation effect affecting radar performance
is ducting. Although young, Loke, Shui, and Chen (2010)
found thatducting is not unique to the local landscape, this
phenomenon, ifnotproperlytreated,maybeexacerbatedby
strongurbanclutterbeyondtheradar’sinstrumentedrangein
alittoralenvironment.
Figure1.Singaporeharbouron27June2013(LC81250592013178LgN01courtesyoftheu.S.geologicalSurvey)
62 DSTA HORIZONS | 2015
Interference
Compared to the open sea, a radar system operating in a
littoral environment iswithin the range of interferences from
shore-basedemitters.Figure3showsa frequencyallocation
chart that depicts a crowdedemission spectrumdue to the
proliferation of commercial communication networks for
aeronautical,landmobile,meteorologicalandsatelliteservices.
POSSIBLE OCCURRENCES
This section will provide insights into some possible
observations due to effects of littoral environment on
surveillance radar systems, the design optimisation required
andtheproposedbestpracticesthathavebeenadoptedfor
front-enddesigndefinitions.
FalseTracks
onemainchallengeofalittoralradarsystemistomaintaina
largedatabaseoftrackswhilereportingataverylowfalsetrack
rate.Forautomatictrackinitiation,averyfrequentoccurrence
is theformationof falsetracksonunwantedtargetssuchas
Figure2.TargetsandtheirtypicalRCSvaluesandvelocities
oil rigs and buoys that are swarming the already saturated
surveillancepicture.Theseeffectsareseentobemoresevere
for areas near urban coastlineswith strong reflective points
suchasbuildings.
To overcome these effects, both plot and track formation
processes have to be examined. Figure 4 is a generic
representation of a track-while-scan (TWS) radar’s tracking
flowwhereeachstepcouldbeafactorcontributingtothefalse
trackperformanceof the system.A systemcanerroneously
initiate a trackwhen there ispoorqualityof inputplots and
a lackofstringentcoherencycheckspriortoassociationsof
plotstotracks.Thisisbecausethequalityofatrackisbased
onthequalityofthetargetkinematicsmeasurementandplot
formation process which includes detection, validation and
unfolding.False trackscanalsobe formedwhen there isan
impropertreatmentofdetectionsofmajorscatterersacrossan
extendedtarget.
Shortsystem latency isoftendesired for fast trackupdates.
However,areductioninsystemlatencyalsotradesoffwaiting
timeessential forcorrectplot-trackassociation,especially in
an environmentwith high target density in adjacent azimuth
sectors.
63DSTA HORIZONS | 2015
Figure3.Spectrumallocationchart(InfocommDevelopmentAuthority,2014)
Typically, radar systems possess track elevation accuracies
intheorderofmilli-radians.However,whentargetsareflying
at lowelevationsof lessthanonebeamwidth,fluctuationsin
elevation accuracies have been observed to be as large as
twice the actual flight level. In addition, the signal to noise
ratio can be so low that there are no target detections in
the multipath nulls. Such erratic elevation measurements
decreasetheoperator’sconfidenceintargetidentificationand
engagement.Figure5showsanexampleof thepropagation
losses due to multipath effects, with increasing values of
attenuationfrombluetored.
DegradedTargetCharacteristics
Inadditiontodetectionandtracking,surveillanceradarsystems
often record the targets’ kinematics and RF characteristics.
An example is the use of the Doppler spread spectrum of
helicopterhubsandblades.TheseRFreturnsaretypicallyvery
weak,withatleast20dBlesssignalstrengthcomparedtothe
TargetMaskingandTrackLoss
It is common tohave large surface vessels in the vicinity of
one another in a littoral environment, possibly with smaller
targetsweavingamongthem.Whenasmallboatapproachesa
largersurfacetarget,thesmallertargetismaskedbythelarger
targetanditstrackdrops.Asradarsystemsarethe‘eyes’of
surveillance ships, such track loss events could place itself
orothers inperilous situations. Ingeneral, highRCS targets
can easily cause a saturation of the radar, masking targets
over an extensive range. This is also an indication of high
time sidelobes1, insufficient dynamic range and poor clutter
rejectiontechniques.
FluctuationsandDegradationsinTrackAccuracies
Propagationlossesandfluctuationsinelevationmeasurements
are the two major effects arising from multipath effects.
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64 DSTA HORIZONS | 2015
mainbodyRCS.Spread spectrumdetectionbecomesmore
challengingwhen thehelicopter is hoveringover landmass.
Additionally,ifthepresenceoftheseDopplermodulationsisa
prerequisiteforexternaltrackreporting,theremightnotbea
helicoptertrackgenerated.
DESIGN BEST PRACTICES
With the accumulation of experiences and identification of
possible areas of improvement, the following best practices
andimportantwatchareashavebeenestablishedtoimprove
front-endradarsystemdefinitionanddevelopment,sothatthe
radarismoresuitedforlittoralsurveillance.
InherentFeatures
Inagoodlittoralradardesign,robustclutterrejectionandfalse
alarm control techniques are essential. To prevent receiver
saturationandhandlestrongclutter,thereshouldbeadequate
dynamic range, sensitivity and gain control. Traditional
methodsofgaincontrolthatapplysimilarsuppressionlevels
over the full radar scan will not be able to deal adequately
with the non-homogenous clutter in a littoral environment.
Adaptiveandsector-basedgaincontrolmethodsmaybemore
effectivesolutions.Similarlyforconstantfalsealarmrate,more
sophisticatedandrigorousmethodswillbeneededtoadaptto
backgroundnoiseandclutterstatistics.
Asmediumpulse repetition frequency is often the preferred
waveformschemeforlittoralradars,thesystemdesignshould
alsoincludethetransmissionandprocessingoffill-inpulses.
Withoutthesepulses,theDopplerresponseswillbewidened,
whichcouldpossiblyleadtomorefalsealarms.However,by
assigningadefaultnumberoffill-inpulses,itispotentiallyusing
upmoreradarresourcethannecessaryforthesuppressionof
clutterreturns.
Figure4.AgenericTWSflowchart
65DSTA HORIZONS | 2015
Doppler measurement is often regarded only as a tool for
determiningatarget’sradialspeed.Infact,Dopplerinformation
can be harvested for target discrimination, false track rate
control and clutter rejection, all of which are indispensable
properties of a littoral radar. For example, in the Doppler
spectrum, surface clutter is characteristically located in the
zeroDopplerbin.Withwell-designedDopplerfiltersandgood
systemstability,surfacecluttercanbesuppressedeffectively.
Inaclusteroftargetswheredetectionsmightbewithinsimilar
range,azimuthandelevationcells,Dopplercanbe themain
discriminator and help lower the probability of track swaps
or splits. Furthermore, ensuringDoppler coherency in signal
processing makes the system more robust against active
jammers.
High tracking accuracy is highly desirable for target
engagementasitimprovestheprobabilityofkillforweapons
using radarplotsor tracksas theirprimary input forballistic
calculations.However,hightrackaccuracycouldalsosignify
adeeprunningofasingletrackmodelfilterwhichisunableto
copewith targetmanoeuvresandsustain trackcontinuity.A
goodsurveillanceradarshouldhaveanimplementationwhich
isalsoabletoprovidehightrackmaintainability.
Tocounteract the increasedriskof interference, littoral radar
systems should have adequate self-protection measures.
Thesemeasures can reside in the front-enddesign such as
low antenna sidelobes, and in signal processing techniques
suchasasynchronouspulserejection,sidelobeblankingand
frequencyagility.
DedicatedTechniquesandArchitecture
With thematurityofsolidstate transmitters, there isamove
towardsActiveElectronicallyScannedArrayradars.Thisclass
of systems is usually associated with high volume search,
flexiblewaveformmultiplexingandgracefuldegradation. This
architecturecanalso improve thesystem’sdynamic range.
Aconventionalanaloguephasedarrayperformsbeamforming
by means of phase shifters before conversion to digital
signal. As such, the analogue to digital converters have a
highriskofsaturationfromthegainoftheantenna.Fordigital
beamforming,beammanipulationisperformedonlyafterthe
signalsateveryelementaredigitallyconverted.Thisresultsin
adynamicrangegainashighasthegainoftheantenna,which
isbeneficialforhandlingstrongclutterreturns.
Littoralradarsystemsshouldalsohavewaveformstocopewith
ad-hocevents.Theclosenessoftheplatformtosurrounding
coastalareascausesittobemorevulnerabletopop-upairand
surfacetargets.Itisthereforedesirableforthesetrackstobe
initiatedwithasfewplotsaspossible,whileretainingalowfalse
trackrate.Tofurtherreducereactiontime,thereshouldalsobe
ahighdegreeofautomationintheoperationoftheradar.As
much as possible, operator actions should be required only
whentheyhaveadditionalthirdpartyinformationwhichcanbe
usedasinputstosupplementtheradar’sperformance.
Figure5.PropagationlossesindBduetomultipatheffects
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SIMULATIONS, TESTS AND FINE-TUNING
Systemdesignreviewsformthebaselinetheoreticalanalysis
of the radar’s capabilities. In order to determine the actual
integrated radar performance, different types of tests from
controlledlaboratorysetupstolocalon-sitetrialsaretypically
conducted.Toevaluatetheeffectivenessoftheimplemented
signalprocessingtechniques,simulationsofRFreturnscanbe
injected in the radar signal processing units. Depending on
thetargetscenariosimulated,parameterssuchasreporting
thresholds and classification criteria can be checked and
furtheroptimised.Fullloadscenarioisoneofthevitalsoftware
teststobeperformedforlittoralradarsystems.Inadditionto
thelargenumberofreportedtracksduetoanexpectedhigh
target density, the radar should also be able to handle the
voluminousinternaldetectionsandunreportedtracksincurred
inalittoralenvironment.
Software simulators are unable to emulate the operational
environmentwithfullfidelityasclutterandpropagationeffects
are often omitted. oneway of filling this gap is to use raw
data collected from similar systems. However, in the usage
ofrawdatafromothersystems,severalareasmustbetaken
careofbyanalysisorscalingtoensurethevalidityofoutput
results.This includes theactual testsetup fromaltitudeand
grazinganglestothescalingofRFfront-endparameterssuch
asantennapatterns,effectiveradiatedpowerandattenuation
settings.
ultimately, local radar testing is the most robust method
of performance validation. Therefore, from a project
management perspective, ample time, sufficient amount of
upfrontplanningandavailabilityofamultitudeoftesttargets
should be catered to allow for comprehensive testing and
fine-tuningof the radar. In general, performance testing can
bebrokendown into: trial planning, conducting of trial, and
analysisofcollecteddata.
In the local environment where both ducting and multipath
can be expected, learning to recognise such propagation
effects and having an in-depth understanding of the impact
ofenvironmentalconditionsarecrucial for trialplanningand
performance analysis. False alarm performance trial is also
verychallenginginalittoralenvironmentcomparedtoanopen
seaasafalsetrackcannotbeverifiedeasily.Hence,variedand
reliablesourcesofgroundtruthneedtobemadeavailableto
validatetheperformanceoftheradar.
LOOKING AHEAD
With improvements in antenna technology and software
processingcapability,manytechniqueswhichwerepreviously
deemedascomputationally intensivehavebecomepractical
toimplementinrealtime.
CognitiveRadar
Haykin(2006)identifiedthreeingredientsofacognitiveradar–
signalprocessingthatbuildsonlearningthroughinteractions
with the surrondings, feedback from receiver to transmitter,
and preservation of collected information. Limited degrees
of cognition are already manifested in many existing radar
modes.AnexampleisLeastJammedFrequency,whereradar
systemssurveythesurroundingspectralenvironmentanduse
these findings to automatically select frequencieswhich are
leastinterferedwithfortransmission.Anotherexampleisthe
mappingofclutterandplotdensitylevelstoprovidefeedback
to the detection process of the radar. For a dynamic littoral
environment,cognitioninradarsystemswillfacilitatecontinual
estimationsandadaptationstotheenvironment.Thiscanlead
tobetterperformanceandreactiontimeinthefuture.
MultipleInputMultipleOutput
Melvin and Scheer (2012) defined a Multiple Input Multiple
output(MIMo)radarasasystemthathasmultipletransmitters
emitting independent waveforms and observes the returns
of the scene of interest with multiple receivers. In a widely
separatedconfigurationasexplainedbyHaimovich,Blumand
and Cimini (2008), MIMo is able to better exploit target
reflectivity using disparate aspect angles, provide enhanced
resolutionofcloselyspacedtargetsandevenimproveDoppler
estimationswiththediversityofreceivedwaveforms.Hence,
the realisation ofMIMosystemscanbring about significant
gainsfortargetdetectionandtrackinginalittoralenvironment.
67DSTA HORIZONS | 2015
CONCLUSION
The complex littoral environment imposes a unique set of
challenges for radar systems. The accrual of experiences in
thisdemanding landscapehas resulted in the formulationof
numerous design best practices such as accurate Doppler
measurements,hightrackmaintainabilityandflexibleresource
allocation.Inadditiontotheserequirements,itisalsopivotal
to understand radar behaviour under local conditions and
validate system performance via simulations and trials
comprehensively. Looking ahead, the advent of new
technologies will enable radar systems to incorporate new
techniques that could further improve performance in the
locallittoralenvironment.
ACKNOWLEDGEMENTS
The authors would like to thank the radar community for
sharingtheirinvaluableknowledgeandwealthofexperience.
Theauthorswouldalsoliketoexpresstheirgratitudetowards
MrTngyanSiongforhiscontinualreviewofthearticle.
REFERENCES
Chia, L. S., Khan, H., & Chou, L. M. (1988). The coastal
environmentprofileofSingapore.Retrievedfromhttp://books.
google.com.sg/books/about/The_Coastal_Environmental_
Profile_of_Sin.html?id=qSIJ2uKKs88C
Dawber, B., &Branson, J. (2005). use of site specific radar
modelling to improveCFARperformance in the littoral. IEEE
InternationalRadarConference,Arlington,VirginiaUSA,161-
166.doi:10.1109/RADAR.2005.1435812
deJongh,R.V. (2005).Naval radar ina littoralenvironment.
IEEE MTT-S International Microwave Symposium Digest,
Amsterdam, The Netherlands, 1457-1460. doi: 10.1109/
MWSyM.2005.1516964
Haimovich,A.M.,Blum,R.S.,&Cimini,L. J. (2008).MIMo
radarwithwidelyseparatedantennas.IEEESignalProcessing
Magazine,25(1),116-129.doi:10.1109/MSP.2008.4408448
Haykin, S. Cognitive radar: a way of the future. IEEE
Signal Processing Magazine, 23(1), 30-40. doi: 10.1109/
MSP.2006.1593335
Infocomm Development Authority of Singapore. (n.d.).
Singapore Spectrum Allocation Chart. Retrieved September
25, 2014 from http://www.ida.gov.sg/~/media/Files/
PCDg/Licensees/SpectrumMgmt/SpectrumNumMgmt/
SpectrumChart.pdf
LC81250592013178LgN01. (2013). In U.S. Geological
Survey. Retrieved from http://earthexplorer.usgs.gov/form/
metadatalookup/?collection_id=4923&entity_id=LC81250592
013178LgN01&pageView=1
Martin,J.,&Mulgrew,B.(1990).Analysisoftheoreticalradar
returnsignalfromaircraftpropellerblades.RecordoftheIEEE
1990InternationalRadarConference.Arlington,VA,569-572.
doi:10.1109/RADAR.1990.201091
Melvin,W.L.,&Scheer,J.A.(Eds).(2012).Principlesofmodern
radar:advancedtechniques.Herts,uK:SciTechPublishing.
Myers, H., & Jarrett, R. (1995). Processing techniques for
surfacesurveillanceradarsinlittoralenvironments.Recordof
theIEEE1995InternationalRadarConference.Alexandria,VA,
33-38.doi:10.1109/RADAR.1995.522515
Skolnik,M.I.,(2002).Introductiontoradarsystems.Newyork,
Ny:Mcgraw-HillHigherEducation.
u.S.EnergyInformationAdministration.(2014,November10).
WorldOilTransitChokepoints.Retrievedfromhttp://www.eia.
gov/countries/analysisbriefs/World_oil_Transit_Chokepoints/
wotc.pdf
u.S.Navy.(2010).Navaldoctrinepublication1:navalwarfare.
Retrieved from https://www.usnwc.edu/Academics/Maritime-
-Staff-operators-Course/documents/NDP-1-Naval-Warfare-
(Mar-2010)_Chapters2-3.aspx
youngK.C.,LokeM.K.,ShuiR.C.&Chen,L.(2010).Ducting
phenomenaandtheirimpactonapulsedopplerradar.DSTA
Horizons,88-99.
ENDNOTES
1 Timesidelobesaretheresponsesfromtheoutputofpulse
compression, which is a technique used to improve radar
rangeresolutionandsignaltonoiseratio.
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68 DSTA HORIZONS | 2015
BIOGRAPHY
LOManLingisaSeniorEngineer(Advanced
Systems). She is currently involved in
the development of sensor systems for
naval platforms. Man Ling graduated
with a Bachelor of Science (Electrical and
Computer Engineering) degree from the
universityof IllinoisaturbanaChampaign,
uSA, in2009.ShealsoobtainedaMaster
ofScience (ManagementScienceandEngineering)degree from
Stanforduniversity,uSA,in2010.
LOKE Mun Kwong is DSTA’s Deputy
Director (Technology)attached to theJoint
Plans and Transformation Department
where he is involved in the strategic long-
term capability development planning
for the Singapore Armed Forces. He
has vast experience working on sensor
system applications for ground, air and
navalplatformsaswell as large-scale systems integration.Mun
KwongwasappointedSeniorAdjunctFellowofTemasekDefence
Systems institute at the National university of Singapore in
2006andhassincebeen lecturingonradarsystems.underthe
Defence Technology Training Award (predecessor of the DSTA
Postgraduate Scholarship), he also graduated with aMaster of
EngineeringdegreewithFirstClassHonoursfromImperialCollege
London,uK,in1995.
69DSTA HORIZONS | 2015
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70 DSTA HORIZONS | 2015
KABANDSATELLITECoMMuNICATIoNSDESIgNANALySISANDoPTIMISATIoN
INTRODUCTION
Various types of satellites, including geosynchronous Earth
orbit(gEo),MediumEarthorbitandLowEarthorbitsupport
beyondlineofsightcommunications.Thelinkbudgetanalysis
inthisarticleisbasedongEosatellites.AgEosatelliteorbits
atafixedlongitudinallocationatanaltitudeofabout36,000km
abovetheequator.Thetranspondersonthesatelliteprovidea
signalboostandfrequencytranslationofsignalsfortheground
terminals.Theantennasonthesatellitearedesignedtoprovide
therequiredcommunicationscoveragetotheterminalsonthe
ground.Thegroundsegmentcomprisesthehubandremote
terminals of different sizes and transmission powers. The
remote terminalscanbehostedondifferentstaticormobile
platforms.
operating intheKabandofferssomesignificantadvantages
overconventionalsatellitenetworksoperatingintheKuband
and lower frequencies.Notonly ismorebandwidthavailable
at the higher Ka band frequencies, Ka band antennas have
higher gain than antennas of comparable size operating at
lowerfrequencies.However,thedisadvantageofusingtheKa
bandisthatadverseweatherconditions impacttheKaband
LEONGSeeChuan,SUNRu-Tian,YIPPengHon
ABSTRACT
Kabandsatellitecommunications (SATCoM) frequenciesprovidenewopportunities tomeethighbandwidthdemands,especiallyforsmallaerial,maritimeandmobilelandplatformssupportingbeyondlineofsightrequirementsfornetwork-centricoperations.Thisispossibleduetotheavailabilityof3.5gHzofbandwidth,andalsobecauseKagroundsegmentcomponentsaretypicallysmallerindimensioncomparedtothoseofKuband.However,KabandlinksexperiencemuchhigherrainfadesintropicalregionsascomparedtoKubandandCband.Inthisarticle,variousfactorsinthelinkbudgetareexploredtodeterminetheirimpactonoverallsignalstrength.ThesefactorscanbetradedoffandoptimisedtoenabletherealisationofaKabandsolutionforSATCoM.
Keywords:Kaband,satellitecommunications,linkbudget,trade-offanalysis,mitigationtechnique
muchmorethanatlowerfrequencies.Itisthereforeimportant
that there is appropriate planning for the implementation of
well-designed ground systems, network links reliability and
resources so as to mitigate these adverse weather effects
(Petranovichl, 2012) (Abayomi Isiaka yussuff, & Nor Hisham
Khamis,2012)(Brunnenmeyer,Milis&Kung,2012).
This article presents a design approach and analysis of key
satellite communications (SATCoM) network parameters
for a Ka band network. Various trade-offs and optimisation
betweenoperationalparameters(e.g.linkavailability),ground
segment(e.g.poweramplifierratingsandantennasizes)and
space segment (e.g. transponderpower andbandwidth)will
be considered. In addition, mitigation techniques such as
hubsitediversity,adaptivecodingandmodulation(ACM)and
uplinkpowercontrolareexploredtomitigatetheincreasedrain
fadesatKabandandimprovetheoveralllinkavailability.This
analysisdemonstratesthatitisfeasibletousetheKabandto
supportmissioncriticalSATCoMoperationsinourregion.
71DSTA HORIZONS | 2015
KA BAND DRIVERS
TheKabandisattractiveasaSATCoMsolutionduetoafew
reasons.
AvailabilityofSpectrumandHigherThroughput
Substantially more spectrum bandwidth is available at the
Ka band than at the Ku band and other lower frequencies.
For example, Ku band allocation is around 2gHz for uplink
and 1.3gHz for downlink with actual contiguous bandwidth
allocation of less than 0.5gHz per satellite. In comparison,
the Ka bandSATCoMhas a bandwidth of 3.5gHz for both
uplinkanddownlink.Table1illustratesthemilitaryandcivilian
frequency allocation.With thewider spectrum availability at
theKaband,highertrafficthroughputcanbesupported.Full
motionvideoforexample,hasbeenidentifiedasakeydriver
inthedemandforbandwidththatcanberealisedbyKaband
satellites (Northern Sky Research [NSR], 2012). In addition,
as theKabandhascommercialandmilitarybandsadjacent
toeachother,commercialservicescanalsocomplementthe
militaryband’scapacity.
GreaterCostEfficiency
Ka band satellites feature narrow spot beams (0.5° to 1.5°
at 3dB beamwidth) which support greater frequency reuse
in geographically isolated spots. With larger allocation and
frequency reuse capabilities, using the Ka band translates
toat leasta1 to2ordermagnitude increase in transponder
throughput,thereforereducingleasingcostperunitbandwidth.
SmallerTerminals
At higher frequencies, wavelengths are smaller, allowing
proportionally smaller, lighter weight and probably less
Band Receive(GHz) Transmit(GHz)
Military 20.2-21.2 30.0-31.0
Civilian 17.7-20.2 27.5-30.0
Table1.FrequencyallocationwithintheKaband
expensiveterminalstoberealised.Thereductionofphysical
dimensions therefore allows Ka band SATCoM to bemade
available for new markets such as manpacks and mobile
platforms.TheuseofmorefocusedandnarrowKabandspot
beams provides higher equivalent isotropic radiated power
(EIRP),signalgain(g/T)andthereforebettersignallinkquality
orhigherdataratesforthesesmallerterminals.Comparingthe
KabandtotheKuband,theimprovementinoveralllinkquality
withtheuseofnarrowspotbeamsis intherangeof6dBto
10dB.
GreaterResiliencytoInterference
WithwiderKabandbandwidth,betterinherentanti-interference
propertiescanbeachieved(e.g.frequencyhoppingordirect
sequencespreadspectrum).WithKabandtranspondersizes
of 125MHz ormore over 54MHz at Ku band, the additional
interferencemarginwithtwicethespreadingcanbeimproved
byatleast3dB.
KA BAND CHALLENGES
WiththeintroductionofsmallermobileterminalsforKaband
SATCoM,morestringentlinkrequirementswillneedtobemet.
Thedesignchallengesareasfollows:
MeetingAdjacentSatelliteInterferenceRegulations
The regulatory bodies governing satellite communications
include the International Telecommunicationunion (ITu) and
the Federal Communications Commission. With the high
densityofsatellitesinorbitandmanymoreKabandsatellites
plannedforlaunch,adjacentsatelliteinterference(ASI)willbe
akeyconcern.Satellite terminals thatwish to transmitmust
meet the emission regulations. ASI is more challenging for
72 DSTA HORIZONS | 2015
smallterminalswheretheantennasidelobepowersarelarge
withrespecttotheirmainlobes,therebylimitingthemaximum
power they are allowed to transmit. When these terminals
areonthemove,allowableemissionsareconstrainedfurther
as the mechanical antenna pointing accuracy experienced
duringshockandvibrationneedstobeaccountedforduring
movementthroughland,variousseastatesorairturbulence.
LargeRainAttenuation
The SATCoM link that passes through the atmosphere is
degradedbyrain,fog,cloud,ice,snowandhail.Thebiggest
challenge in using the Ka band is the high rain attenuation
compared with the Ku band and higher rainfall rates in
the tropics. Since the electromagnetic wave absorption
componentisincreasedatKaband,theamountofattenuation
per unit length is also increased (see Figure 1). Additional
margin isneededtoensurehighsystemavailabilityortrade-
off in link availability. However, adding an additional margin
may be impractical for remote terminals with small antenna
andlowpoweramplifierthatoperatesinhighrainfallregions.
Forexample,collectedrainstatistics inSingaporegenerated
by Leong and Foo (2007) show a higher rain rate than ITu
specifications (International Telecommunications union –
RadiocommunicationsSector[ITu-R],2012).Thisresultsina
downlinkrainlossof12dBattheKabandversus2.6dBatthe
Kubandtoachieve99%linkavailability.Inadditiontohigher
attenuation,therainfaderateattheKabandwillbeverymuch
higherthanattheKuband.Thehighrainfaderatewillimpact
theoperationofmitigationmeasuressuchasACMalgorithms
builtintothesatellitemodem.
MITIGATION TECHNIQUES
The large rain attenuation at the Ka band may not be
compensatedfullybytheimprovementinKabandnarrowspot
beamsandbetter interferenceenvironment.Degradations in
linkqualitycanbefurthermitigatedbyemployingthreemain
techniques.
HubSiteDiversity
Sitediversityisafademitigationmeasurethatinvolvestwoor
morehubterminalssetuptotransmitorreceivethesignalin
realtimebyusinganalgorithmtochoosetheleastamountof
linkdegradationamongallthehubsitesatanyoneinstance.
Whenonehubexperiencesrainanddetectsthatthelinkmay
becut, thealgorithmcalls foraswitchover to theotherhub
wherethereareclearskies(seeFigure2).
Forsitediversitytobeuseful,therearetwomainconsiderations.
First,hubsitesmustbesufficientlyseparatedtoachievethe
required diversity gain or diversity improvement factor. It is
shownthatdiversitygainimproveswithdistancebutthegain
tapersoffatdistancesmorethan11kmasitcanbetreatedas
asinglesitefadeevent(Leong,Loh,Chen,yip,&Koh,2012).
Table2showsthatthediversitygain isnot justafunctionof
distancebutalsotheorientationofthelineconnectingthetwo
Figure1.Rainattenuationstatisticsat30degreeselevation
73DSTA HORIZONS | 2015
sites.ThediversitygainforSentosa-Woodlands(South-North
direction)isalmostequivalenttotheTuas-Changi(West-East)
sitecombinationalthoughthedistancebetweeneachpairof
sitesisquitedifferent.Second,whenasitediversitydecision
ismade,thedowntimeincurredfromthehubswitchoverand
the predicted duration of rain outage must both be taken
intoaccount.Due to thecomplexityofsitediversityand the
resultingcostofimplementation,itwillbemorecosteffective
touseKabandsatellitenetworks.
The hub diversity concept can similarly be extended to
remoteterminals.Inabentpipelink,whenthetransmitterand
receivers are locatedat adistanceapart, the twositesmay
notexperiencethesameamountofrainfallbuttherainfallat
thesitesmaybecorrelated.Therefore,inatypicallinkbudget
planning, the dual rain fade conditions for both the uplink
and downlink are considered when the distance between
the transmitter and receiver is less than 3km. For distances
greaterthan50km,asinglerainfadecondition,usuallyonthe
uplinkside,isconsidered.Inthesetwoplanningmethods,the
rangeofrainattenuationat99%totallinkavailabilityattheKa
bandvariesfrom12dBto39dB.Duetothislargeattenuation
range, it is therefore important toplan the attenuation value
accuratelysoastomeettheenduserservicelevelagreement
while optimising the entire ground and space resources
(Leong,2012).
Figure2.Illustrationofhubsitediversity
Primary Hub
Remote Terminal
Satellite
Secondary Hub
SelectionCombination DivGain/dB Dist/km
Tuas-Sentosa 11.2 22.72
Tuas-Woodlands 10.1 24.40
Sentosa-Woodlands 13.9 23.62
Sentosa-Changi 8.8 23.13
Woodlands-Changi 12.0 27.49
Tuas-Changi 14.8 42.44
Table2.Diversitygainimprovementoverasinglesite
KABANDSATELLITECoMMuNICATIoNSDESIgNANALySISANDoPTIMISATIoN
74 DSTA HORIZONS | 2015
Figure3.Majorlinkparametersusedinlinkbudgetanalysis
Hub + Antenna size/gain + Power -‐ Backoff -‐ Losses -‐ Intermodula<on -‐ ASI regula<ons
Remote terminal + Antenna size/gain + Power -‐ Backoff -‐ Losses -‐ Intermodula<on -‐ ASI regula<ons
Outbound Link Inbound Link
Legend:
Satellite • Satura<on Flux Density • Transponder linearity • Transponder bandwidth • G/T, EIRP • Intermodula<on
Link parameters • data rate • MODCOD scheme • Link availability
Propaga6on models • Free space • Precipita<on • Cloud
AdaptiveCodingandModulation
InACM,themodulationandcoding(MoDCoD)ofthecarrier
is altered within the modem in step sizes to increase the
survivabilityof the transmission link.Bydecreasing thedata
rate, thesignal tonoise ratio required fora lowerMoDCoD
is reduced and therefore the carrier becomesmore resilient
to rain fade. To support a varying data rate transmission
during dynamic rain conditions, the video codec running in
the application layer should allow a seamless reduction in
videoqualityorresolutiontoensurethattherecipientisable
toreceiveit. Inotherwords,byadjustingtheMoDCoD,it is
possible tooptimise the trade-offbetweenperformanceand
survivability.Applications thereforeneed tobedesignedand
testedaccordinglytotakefulladvantageoftheACMcapability.
ACMtypicallyprovides15dBofmarginacrossthefullrangeof
MoDCoDs.
AutomaticUplinkPowerControl
Automatic uplink Power Control (AuPC) is implemented by
increasing carrier power at the transmit end to ensure link
survivability. When a rain fade event is encountered, more
powerisdrawnfromthehighpoweramplifier(HPA)tomaintain
the carrier to noise ratio. Due to the need for additional
equipment, AuPC is usually employed only at larger hub
stationssincethesmallerremoteterminals’HPAmayalready
beoperatingwithnegligiblebackoffduringclearsky.AuPCat
hubstationstypicallyprovide15dBofpowercontrolmargin.
DESIGN ANALYSIS AND OPTIMISATION
Takingintoconsiderationspacesegmentparameters;ground
segmentmitigation techniques that improve the link quality;
environmentfactorsthatdecreasethelinkqualitysignificantly;
and the increased use of high bandwidth demand video
application, a more stringent design analysis approach for
link budget calculations is required. The approach will also
requireasensitivityanalysis,wherevarioustrade-offsbetween
operationalparameters(e.g.desiredlinkavailabilityforcontrol
andmissionlinks),groundsegment(e.g.poweramplifierratings
and antenna sizes) and space segment (e.g. transponder
power and bandwidth) can be analysed and optimised.
Throughthesetrade-offanalyses,thefeasibilityofusingtheKa
bandtosupportmissioncriticalmilitaryaeronautical,maritime
andlandSATCoMoperationscanbedetermined.
Therearemanyparameterstoconsiderinthelinkbudget.The
primaryparametersareasshowninFigure3.
75DSTA HORIZONS | 2015
It is recommended to start the satellite network design by
first identifying the design boundaries –which are themost
constraining factor(s) and which are the parameters that
arewithin and outside of the designers’ control. The typical
constraintsareasfollows:
Satellites
usually,theareaofoperationswilldefinethechoiceofsatellites.
If two or more satellites are able to provide the required
coverage, thenparameters suchas theavailablepowerand
bandwidthonthetransponder,receiverg/T,saturationpoints
ofthereceiversandsaturationfluxdensity(SFD)canbeused
forthetrade-offanalysis.The linearityof thetransponders is
also an indicator of their performance. Themore linear they
are,thelowertheintermodulationnoiserelativetothecarrier
will be produced, and therefore the better the output signal
whichcanbeachieved.
RemoteTerminalsandHub
Constraints for remote terminals include the infrastructureor
platformtheywillbehostedin.Iftheterminalsaretobeused
onthemove,theplatformwillverylikelylimittheantennasize/
weight, position, minimum/maximum elevation angles and/
orpoweramplifiersize.Ifthehubhasbeenimplemented,its
fixedinfrastructuresuchasantennasizeandpoweramplifier
size may be constraining factors. Transmit power back-off
(reduction in the transmit power level) and intermodulation
noiseshouldbecatered for ifmultiple frequencycarriersare
transmitted from a common power amplifier. Losses due to
cablesandinterconnectorsaswellasinaccuraciesinantenna
pointingshouldalsobetakenintoaccount.
Besides these technical parameters, the satellite network
designershouldalso takemarketavailabilityof theproducts
intoconsideration.
CommunicationLinks
a) Outbound Link - The outbound link is the overall
communicationslinkfromthehubtotheterminal.Itconsistsof
thehubuplinkandtheterminaldownlink.Theoutboundlinkis
generallyengineeredsothattheterminaldownlinkdominates
performance. Since the hub services many terminals, it is
generallycosteffectivetomakethehubantennalargeenough
toprovideextratransmitpowermarginonthehubuplink.
b) Inbound Link - The inbound link is the overall
communicationslinkfromtheterminaltothehub.Itconsistsof
theterminaluplinkandthehubdownlink.Theinboundlinkis
alsogenerallyengineeredsothattheterminaluplinkdominates
performance, since the large hub antenna provides extra
receivegainonthehubdownlink.
c) MODCODScheme-ThechoiceofMoDCoDisrelatedto
thesignaltonoiseratiorequiredbythemodemtodemodulate
the signal successfully as well as the carrier bandwidth
required. These parameters are usually referenced from the
modem specifications. The available transmit power or the
receiversensitivitymaylimitthechoiceofMoDCoDscheme.
OperationalInputs
The operational inputs consist of the information exchange
requirements, data rates and link availability required for
themission. Depending on the application andmission, the
end user may have minimum data rate and link availability
requirements.Thesewouldthenbesetasdesigntargetsand
inputs to the link budget analysis. They impact the satellite
transponderresourcesdirectlysuchaspowerandbandwidth
requiredtosupportthelink.
CASE STUDY: SATCOM ON THE MOVE
A remote terminal antenna size of 0.45m or 0.6m, power
amplifierofupto20Wandaninboundlinkofupto5Mbpsare
usedastheinputparametersinthiscasestudy.Ifthechoiceof
satelliteisstillopen,thedesignershouldlookforonewithhigh
g/Tandhighlinearitytransponderinordertomeetthedesired
link availability for the mission and minimise the resources
required.
SensitivityAnalysis
With numerous link budget parameters, sensitivity analysis
is needed to determine the critical trade-offs between size,
power, bandwidth and link availability. The key findings are
highlightedasfollows:
a) Increasing remote terminal antenna size from 0.45m to
0.60mallowsa reduction in the required transponderpower
equivalent bandwidth (PEB) by 20% to 40% per 64Kbps
link, leading to long-term savings in operating expenses. At
thesametime,itallowstherequiredpoweronthehubtobe
reducedby30%to40%.Bothdirectlycontributetoanincrease
inthenumberofremoteterminalsthatcanbesupported.
KABANDSATELLITECoMMuNICATIoNSDESIgNANALySISANDoPTIMISATIoN
76 DSTA HORIZONS | 2015
b) Itisestimatedthatasingletranspondercansupportabout
9x5Mbpsor16x3Mbpsmissionlinks.Forthemissionlink,
satelliteSFD–aparametercontrolledbythesatelliteservice
provider–andtheEIRPcontourinwhichthehubis located,
are themajor factors influencing the number of links which
can be supported per satellite transponder. Increasing the
SFD sensitivity level by 6dBW/m2 reduces the transponder
PEB requiredby60%to70%, leading tosignificantsavings
in operating expenses. It is therefore important to choose,
negotiateandestablishaservicelevelwiththesatelliteservice
providerwhichmeetuserrequirements.
c) Foramissionlinkwithhighdatarate(3Mbpsto5Mbps)but
smallantenna(0.45mto0.6m)andlimitedpower(upto20W),
themaximumlinkavailabilityisonly96%to97%.Withlower
datarates(below1Mbps),ahigher linkavailabilityofat least
98%canbeachieved.
ApplicationofMitigationTechniques
Hub Site Diversity
Hub site diversity provides a means to overcome rain fade
onthepathbetweenthehubandthesatellite.Consequently,
whenthereisnorainattenuation,thenumberoflinksthatcan
be supported per transponder/hub increases. In essence,
this increases the total capacity of the satellite network in
termsof increasing thenumberof remote terminals thatcan
besupportedper satellite transponder.For remote terminals
equipped with 0.45m antenna and up to 20W power, hub
site diversity can increase the number of remote terminals
supportedpertransponderbyupto18%.
Adaptive Coding and Modulation
ThemissionlinkavailabilitywillbeimprovedifACMisapplied.
Duringraineventswhenthelinkfunctionsindegradedmode,
forexampleata lowerdatarate,videosaretransmittedata
lowerresolution.Bydecreasingthedatarate from1Mbpsto
512Kbpsor256Kbps,thelinkavailabilityisincreasedfrom98%
to98.5%.This translatestoareduction indowntimeof43.8
hoursperyear.Commercial-off-the-shelfsatellitemodemsare
usuallyequippedwithACMthatenablethelinktobesustained
aslinkconditionsdeteriorate.
OperationalConsiderations
Besidesdesigninganetworkwiththerequiredlinkavailability,
data ratesandpower, it isnecessary toaddressoperational
concernsandplanforcontingencies.
Impact of Loss of Mission Link and Mitigation
Alinkof64Kbpscouldbelostinrainexceedingapproximately
20mm/hr.Theimpacttothemissiondependsonfactorssuch
as theperiodof linkoutageand latency requirementsof the
data.Mitigatingmeasuresforlinkoutagecanincludeastore-
and-forwardmethodwherebythedataisstoredonboardthe
platformuntilacommunicationslinkisre-established.
Link Resiliency
Thelinksshouldbedesignedtoberobustagainstintentional
or unintentional interferences. The communications security
andtransmissionsecurityfeaturesoftheSATCoMlinkdepend
toalargeextentonthemodemcapabilitiesandwaveform.The
accuracyoftrackingandpointingaswellasthedesignofthe
SATCoM antennas, especially on side lobe emissions, also
playapartinreducinginterferencesinthenetwork.
77DSTA HORIZONS | 2015
CONCLUSION
The use of the Ka band in SATCoM has allowed for new
and smaller mobile terminals that utilise high throughput
applications as compared to the Ku band to be feasible
options in operations. However, with significantly larger rain
attenuation to overcome, the Ka band link budget design
analysis ismore complex than in lower frequency bands to
achievecomparablelinkavailability.Theuseofsensitivityand
trade-offanalysisintheillustratedSATCoMonthemovecase
studydemonstratesthefeasibilityofKabandSATCoMinour
region.otherKabandoperationalconsiderations–suchasthe
possibilityof fallback to lower frequencybandduringsevere
fade conditions and change in transmission plans required
whencrossingovermultiplespotbeamstocovertheareaof
operation–mayalsobeincludedaspartofthedesignanalysis
uponfutureexploration.
REFERENCES
Abayomi Isiaka yussuff, & Nor Hisham Khamis (2012). Rain
attenuationmodellingandmitigationinthetropics:briefreview.
InternationalJournalofElectricalandComputerEngineering,
2(6),748.
Brunnenmeyer, D., Mills, S., Patel, S., Suarez, C., & Kung,
L. (2012, october). Ka and ku operational considerations
for military SATCoM applications. Military Communications
Conference,2012–MILCOM2012.
International Telecommunications union –
Radiocommunications Sector. (2012). Characteristics of
precipitationforpropagationmodelling(P.837-6).geneva.
Leong, S. C. (2012). Extraction of distance-dependent rain
rate distributions for satellite links calculation. Progress In
ElectromagneticsResearchSymposiumProceedings,Russia.
1571–1575.Retrievedfromhttp://piers.org/piersproceedings/
piers2012MoscowProc.php?start=300
KABANDSATELLITECoMMuNICATIoNSDESIgNANALySISANDoPTIMISATIoN
Leong,S.C.,&Foo,y.C. (2007,December).Singaporerain
ratedistributions.6thInternationalConferenceonInformation,
Communications&SignalProcessing,2007.
Leong,S.C.,Loh,W.J.,Chen,y.J.,yip,P.H.,&Koh,B.T.(2012).
Evaluationofsitediversityeffectivenessusingweather radar
data for Singapore. Progress In Electromagnetics Research
SymposiumProceedings,Malaysia,620–625.Retrievedfrom
http://piers.org/piersproceedings/piers2012KualalumpurProc.
php?start=100
NorthernSkyResearch.(2012).Government&militarysatellite
communications(8thed.).Cambridge,MA:NSR.
Petranovich, J. (2012). Mitigating the effect of weather on
ka-band high-capacity satellites. Retrieved from https://
www.viasat.com/files/assets/Broadband%20Systems/
Mitigating%20the%20Effect%20of%20Weather%20on%20
Ka-Band%20High%20Capacity%20Satellites.pdf
78 DSTA HORIZONS | 2015
BIOGRAPHY
LEONG See Chuan is a Development
Manager (C4I Development). He has
designed,developedandmanagedcomplex
software based command and control
systemsincludingsatellitecommunications
(SATCoM). He has published numerous
academic publications, some of which
are related toSATCoM,withabestpaper
presentationawardinanIEEEconference.ArecipientofthePublic
Service Commission Scholarship, See Chuan graduated with
a Bachelor of Engineering (Electrical Engineering) degree from
the National university of Singapore (NuS) in 1999. He further
obtainedaMasterofEngineering (ElectricalEngineering)degree
fromNuSin2002.
SUN Ru-Tian is a Principal Engineer
(Advanced Systems). She was a project
manager for ground SATCoM systems
and is currently involved in the front-end
planning in the domain of communication
switching systems and radios. A recipient
of the DSTA undergraduate Scholarship,
Ru-Tian graduated with a Bachelor of
Engineering(ElectricalEngineering)degreefromNuSin2005.She
further obtained aMaster of Science (SatelliteCommunications
Engineering) degree from the university of Surrey, uK, in 2009
undertheDSTAPostgraduateScholarship.
YIP Peng Hon is a Senior Principal
Engineer (Advanced Systems) who has
many years of experience managing
large-scale communications network
projectsforgroundandnavalplatforms.He
iscurrentlyinvolvedinthefront-endplanning
and systemsarchitectingof theSingapore
Armed Forces’ SATCoM capabilities.
Peng Hon graduated with a Bachelor of Engineering (Electrical
Engineering) degree and aMaster of Science (Communications
andComputerNetworking) degree fromNanyang Technological
universityin1993and2000respectively.
79DSTA HORIZONS | 2015
KABANDSATELLITECoMMuNICATIoNSDESIgNANALySISANDoPTIMISATIoN
80 DSTA HORIZONS | 2015
PERFoRMANCECHALLENgESFoRHIgHRESoLuTIoNIMAgINgSENSoRSFoRSuRVEILLANCEINTRoPICALENVIRoNMENT
INTRODUCTION
In the modern battlefield, high resolution imaging sensors,
typicallyoperatinginthevisibleorinfrared(IR)electromagnetic
(EM) spectrum, provide a distinct advantage by detecting
targets and offering an unambiguous means of target
identification.However,environmentalconditionscanlimitthe
performanceofsuchsystemsduetotheeffectsofatmospheric
gasesandaerosolsonEMwaves.Specifictothelocaltropical
environment,keyfactorsaffectingsensorperformanceinclude
humidity, rain,cloudsandhaze.Thesefactors, togetherwith
thebasicattenuationmechanisms,arecoveredindetailinthe
followingsections.
TYPES OF IMAGING SENSORS
Imaging sensors can be broadly classified into passive and
active imagingsensors.Apassive imagingsensor intercepts
andcollectssurroundingEMradiationreflectedofforemitted
byobjectsfoundwithinthefield-of-viewofitsdetectortoform
imagesofitssurroundings.Anactiveimagingsensoriscoupled
with an illumination source to illuminate the objects to be
LEECheowGim,EEKokTiong,HENGYinghuiElizabeth
ABSTRACT
Electro-optical(Eo)sensorsofferanunambiguousmeansoftargetidentification,albeitwithlimitationsinrangeperformanceduetoenvironmentalconditions.Specifictothelocaltropicalenvironment,factorsaffectingsensorperformanceincludehumidity,rainandclouds.Anotheremergingkeyenvironmentalfactor isthepresenceofhaze.Thisarticleexaminesthephysicsbehind theseenvironmental factorsand their impacton theperformanceofdifferentsensors. ItalsodiscusseshowspecificEocharacteristicscanbeleveragedtoenhancesensors’performanceinthelocalenvironmentandhighlightsemergingtechnologiesforfutureconsideration.
Keywords:electro-optical,targetidentification,imagingsensor,rangeperformance,attenuation
observed.Acompatibledetectorwillthencollectthereflected
energy for extended surveillance range performance and
betterspatialresolutionunderlowlightandindarkconditions.
Different detectormaterials are sensitive to radiation energy
fromdifferentportionsoftheEMspectrum.
Intheday,thedominantsourceofvisiblespectrumradiation
is thesun,whileatnight,asignificantamountofnightglow
comes from the moon and stars. Detectors that operate
in the visible spectrum typically make use of either the
charge coupled device or the complementary metal oxide
semiconductortechnologiesforimagingindaytimescenarios
when ample ambient light exists. Detectors using image
intensifier(II)technologymakeuseofphotonamplificationto
generateimagesinlow-lightscenarios.
on the other hand, thermal imagers (TI) are used to detect
heatorradiationemittedfromhotobjectsinthemidwaveIR
(MWIR) or longwave IR (LWIR) spectrums to generate two-
dimensionalimages,basedontheblack-bodyradiationcurve
and thecontrastbetween the temperaturesof theseobjects
and theirbackground.These imagersoperate independently
81DSTA HORIZONS | 2015
from ambient lighting condition and even in complete
darkness. TI detectors are further classified into two types
– one that relies on changes to the temperature-dependent
property of itsmaterial, and another that determines the IR
photon flux by measuring the electrical current due to the
generation of electron-hole pairs caused by the absorption
of incidentphotons.Commonmaterialsused to fabricateTI
detectorsareindiumgalliumarsenide(IngaAs),leadsulphide,
indiumantimonide,mercurycadmiumtellurideandvanadium
pentoxide.
BASIC ATTENUATION MECHANISMS
Atmosphericattenuationiscausedbyboththeabsorptionand
scatteringofEM radiation fromaerosolparticlesormoisture
dropletssuspendedintheatmosphere.EMradiationismainly
absorbed by gaseous agents such aswater vapour, carbon
dioxide,nitrousoxide,ozone,molecularandatomicoxygen,
andnitrogen.Theabsorptionisgenerallynegligibleinthevisible
regionandataminimuminafewatmosphericwindowsinthe
IRregion.ThewindowbandsinthevisibleandIRspectrumare
summarisedinTable1andillustratedinFigure1.
AtmosphericscatteringistheprocessbywhichEMradiation
is redirected by gaseous molecules and aerosol particles
suspendedintheatmosphere.Itisgovernedbytherelationship
betweentheradiiofthescatteringmoleculesorparticlesand
thewavelengthoftheincidentradiation.
Atmosphericabsorptionandscatteringcreateatwo-foldeffect
on luminanceandcontrast transmittance.First,EMradiation
WindowBandsinEMSpectrum Wavelength
Visible 0.4µmto0.7µm
NearIRandShortIR 1µmto2µm
MidIR 3µmto5µm
FarIR 8µmto12µm
Table1.WindowbandsinthevisibleandIRspectrum
Figure1.AtmosphericwindowsinthevisibleandIRregions
froma targetand its immediatebackground isprogressively
scattered out of the viewing path. Some will be absorbed
andwillnotreachthesensor.TheattenuationofEMradiation
followsanexponentiallawinhomogeneousair.AbeamofEM
radiationcontainingafluxFoatthetargetofrangeRfromthe
sensorwill have a residual fluxF received by the sensor in
homogeneousair,givenby:
3
Atmospheric scattering is the process by which EM radiation is redirected by gaseous molecules and aerosol particles suspended in the atmosphere. It is governed by the relationship between the radii of the scattering molecules or particles with the wavelength of the incident radiation.
Atmospheric absorption and scattering create a twofold effect on luminance and contrast transmittance. First, EM radiation from a target and its immediate background is progressively scattered out of the viewing path. Some will be absorbed and will not reach the sensor. The attenuation of EM radiation follows an exponential law in homogeneous air. A beam of EM radiation containing a flux Fo at the target of range R from the sensor will have a residual flux F received by the sensor in homogeneous air, given by:
)exp(])(exp[ RFRkbFF eoo
where b and k are the scattering coefficient and absorption coefficient respectively, and σe is the extinction coefficient of the atmosphere. Second, EM radiation, which does not come directly from the target or its immediate background, is scattered into the viewing path. This additional radiation is called airlight or path radiance, and varies with the scattering angle.
ATMOSPHERIC ATTENUATION IN THE LOCAL ENVIRONMENT
The key atmospheric elements in our local environment which attenuate the sensors’ performance in the visible and IR spectrum are rain, clouds, fog and haze. The first three elements are related to the presence of water vapour, which is the most influential absorbing gas as well as the most variable. Relative humidity and absolute humidity are the two environmental parameters associated with water vapour content.
Rain Attenuation
Rain effects are difficult to estimate because of the variation in droplet size, density, drop size distribution, phase function, raindrop shape and the different effects that the water refractive index has on different waveband portions of the EM spectrum. Rain attenuates EM radiation through absorption and scattering, with the relative amounts dependant on the ratio of raindrop radius to wavelength. In the visible and IR spectrums, attenuation by rain is independent of wavelength because the raindrop radius (typically from 0.5mm to 5mm) is much larger than the wavelength. The extinction coefficient, which measures how strongly the EM radiation is absorbed by the medium (rain), indicates that the greater the rainfall rate, the higher the absorption.
Rainfall is the most significant atmospheric element affecting sensors operating in the visible and IR portions of the EM spectrum in Singapore, where rainfall occurs every month of the year. The two main wet seasons are the Northeast monsoon season from late November to March, and the Southwest monsoon season from late May to September, which account for 48% and 36% of the annual rainfall respectively. The type of rainfall varies from drizzle, which has a rain rate of up to 1mm/hr, to
82 DSTA HORIZONS | 2015
whereb and k are the scattering coefficient and absorption
coefficient respectively, and σe is the extinction coefficient
of the atmosphere. Second, EM radiation, which does not
come directly from the target or its immediate background,
isscatteredintotheviewingpath.Thisadditionalradiationis
calledair-lightorpathradiance,andvarieswiththescattering
angle.
ATMOSPHERIC ATTENUATION IN THE LOCAL ENVIRONMENT
Thekeyatmosphericelementsinthelocalenvironmentwhich
attenuate the sensors’ performance in the visible and IR
spectrumarerain,clouds,fogandhaze.Thefirstthreeelements
arerelatedtothepresenceofwatervapour,whichisthemost
influentialabsorbinggasaswellasthemostvariable.Relative
humidity and absolute humidity are the two environmental
parametersassociatedwithwatervapourcontent.
RainAttenuation
Raineffectsaredifficult toestimatebecauseof thevariation
indropletsize,density,dropsizedistribution,phasefunction,
raindrop shape and the different effects that the water
refractiveindexhasondifferentwavebandportionsoftheEM
spectrum. Rain attenuates EM radiation through absorption
and scattering, with the relative amounts dependant on the
ratio of raindrop radius towavelength. In the visible and IR
spectrums,attenuationbyrainisindependentfromwavelength
becausetheraindropradius(typicallyfrom0.5mmto5mm)is
much larger than thewavelength. The extinction coefficient,
whichmeasureshowstronglytheEMradiationisabsorbedby
themedium (rain), indicates that thegreater the rainfall rate,
thehighertheabsorption.
Rainfall isthemostsignificantatmosphericelementaffecting
sensors operating in the visible and IR portions of the EM
spectruminSingapore,whererainfalloccurseverymonthof
theyear.ThetwomainwetseasonsaretheNortheastmonsoon
season from late November to March, and the Southwest
monsoonseasonfromlateMaytoSeptember,whichaccount
for48%and36%oftheannualrainfallrespectively.Thetype
of rainfall varies fromdrizzle,whichhas a rain rate of up to
1mm/hr,tothunderstormswithrainratesexceeding50mm/hr.
Thunderstormsareobservedduring78%of thosedayswith
rainfall.ToillustratetheimpactofrainonvisibleorIRsensors,a
moderaterainrateof10mm/hrwouldallowonlyapproximately
6.7%oftheEMradiationtopassthrougha1.8kmpath.Along
a10kmpath,thetransmittanceeventhroughalightrainwith
rain rate of 2.5mm/hrwouldbeonly 0.1%.Thismeans that
visible and IR sensors are renderedalmost useless in either
case.Table2showsthevariousrainfallstatisticsfordifferent
inputparameters(Bernardetal,2013).
Rainrate 5mm/h
(lightrain)
10mm/h
(moderaterain)
20mm/h
(heavyrain)
Extinction 0.5km-1 0.7km-1 ~1.2km-1
WaterVolume/RainVolume 320mm3m-3 588mm3m-3 1070mm3m-3
Numberofraindrop 3600m-3 4800m-3 6400m-3
Table2.Variousrainfallstatisticsfordifferentinputparameters,computedusingMarshall-Palmerdistribution
83DSTA HORIZONS | 2015
CloudAttenuation
Similar torain,cloudeffectsaredifficult to forecastbecause
of the variation inparticle size.Attenuation isdependenton
thecloudtypeandwatervapourcontent.Withinthecloud,the
attenuationofEMradiationbywaterdroplets isdue toboth
absorptionandscattering.
CloudsinSingaporetendtohavehigherwatercontentbecause
warmerairholdsmoremoisture thancolderair.Themedian
cloud cover in Singapore is 90% (mostly cloudy) and does
not vary significantly. The typical cloud forms in Singapore
are cirrus clouds (high clouds with bases above 20,000ft),
altocumulus clouds (medium clouds with bases between
7,000ft to 20,000ft) as well as cumulus and cumulonimbus
clouds (low clouds with bases below 7,000ft). The typical
cloudthicknessrangesfrom1kmto6kmwiththeradiiofthe
cloudwaterdropletsrangingfromabout0.5µmto80µm.The
extinction coefficient increases by an order of 10 for every
kilometreofcloudthickness.Hence,theverticaltransmittance
through such clouds would be less than 0.005%, and the
cloudswouldbeopaquetovisibleandIRradiation.
FogAttenuation
Water vapour in the air usually condenses high in the
atmospheretoformcloudsbutitcanalsocondensecloseto
thegroundtoformfog.Fogformswhenthedifferencebetween
atmospherictemperatureanddewpointislessthan2.5°Cand
occursatrelativehumiditynear100%,whichmeansthatthe
airwillbecomesupersaturatedifadditionalmoistureisadded.
Whentheairisalmostsaturatedwithwatervapouratrelative
humidityofcloseto100%,fogcanforminthepresenceofa
sufficientnumberofcondensationnucleiwhichcanbesmoke
or dust particles. The reason for degradation of visibility in
a foggy atmosphere is the absorption and scattering of EM
radiation by fog particles. The degradation is dependent on
thedropletsizeanditsdistribution.Foghassimilareffectsto
thatofclouds.
In Singapore, fog is most likely to occur during the inter-
monsoon periods, at times when winds are light and on
cloud-free nights with high humidity. on the average, the
dewpoint forSingaporevariesfrom22°Cto27°C,whilethe
atmospheric temperature varies from a low 25°C to 27°C
during the monsoon seasons and inter-monsoon periods
respectively.Thefogobserved inSingapore ismainlydueto
radiative cooling of the land,which causes the temperature
of the air near ground level to fall within 2.5°C of the dew
point, resulting in thecondensationofwaterdroplets. It can
beobservedthatattenuationduetoanevolvingfogdecreases
rapidlywithincreasingwavelength.Hence,IRsensorsperform
betterthanvisiblesensorsinfoggyconditions.Thesameisnot
truefortransmissionthroughstablefog,whereIRattenuation
issoseverethatIRsensorshavelittleadvantageovervisible
sensors.
DeterminingVisibleandInfraredSensorPerformanceUsingTransmittance
Visualrangeisameasureofvisibility(Malm,1999).Thelarger
thevisualrange,thebetterthevisibility.Visibilityiscalculated
fromameasurementofEMradiationextinctionwhichincludes
thescatteringandabsorptionoflightbyparticlesandgases.
Innaturalweatherscenarios,transmittancealongtheline-of-
sightbetweenthesensoranditstargetisdegradeduniformly.
Thisdegradationischaracterisedbyanextinctioncoefficient
αkm-1.Theextinctioncoefficientquantifieshowthepassage
oflightfromascenetoanobserverisaffectedbyairparticles
(Malm,1999).Theextinctionisdependentonparticlemassand
chemicalcomposition.Toestimatetheperformanceofsensors
inman-madeinducedobscurants,transmittancedegradation
in the form of a mass extinction coefficient α’ m2/g for the
obscurantisaddedtonaturalweatherdegradation.Hence,to
determine the sensorperformance, its transmittancecanbe
calculatedusingtheequation:
Transmittance,T=exp(-αR-α’CL)
Whereα = ambientatmosphereextinctioncoefficient(km-1)
R = range(km)fromtargettosensor
α’ = inducedobscurantmassextinctioncoefficient (m2/g)
CL= induced obscurant concentration pathlength
(g/m2)
Inotherwords,rangecanbecalculatedas:
R=-[ln(T)+ α’CL]/α
Therangeequationshowsanegativelogarithmicrelationship
to transmittance. However, the equation does not show a
direct relationship towavelength as it is affected to varying
degreesbyambientatmosphereandobscurant.
Whiletheaboveequationsprovideageneralguideonpredicting
sensorperformance,itmustbenotedthattheindustryemploys
more complex simulation software such as the TACoM
Thermal ImageModel, NVThermIP withMoDTRAN, NVESD
PERFoRMANCECHALLENgESFoRHIgHRESoLuTIoNIMAgINgSENSoRSFoRSuRVEILLANCEINTRoPICALENVIRoNMENT
84 DSTA HORIZONS | 2015
TimeDependentSearchParameter searchmodel for search
and detection predictions, andmost recentlyNVLabCap for
detailedanalysisandpredictionofsensorperformanceunder
differentenvironmentalconditions.Thesesoftwareareableto
evaluateimagingsensorsystemperformancecomprehensively
based on multiple factors including system design and
tolerances which cannot be adequately represented in the
equations mentioned. The NVESD Time Dependent Search
Parameter search model, NVThermIP and NVLabCap are
authoritative simulation systemsdevelopedby theuSArmy
NightVisionandElectronicSensorsDirectorateovertheyears
to improve the accuracy and repeatability of measurement
techniques,intheirefforttocharacteriseandevaluateavariety
ofEoimagingsystemsfortheuSArmy.
ImpactofHazeonSensorPerformance
Haze refers to small particles dispersed throughout the
atmospheric aerosol (Chen, 1975). Biomass burning is a
global phenomenon that releases large quantities of gases
and aerosol particles into the atmosphere, affecting the
atmospheric chemistry and climate on a large scale via
the scattering and absorption of solar radiation (Li, Shao, &
Buseck, 2010). Aerosols in regional hazes are contributed
largelybyanthropogenicsourcessuchasindustrialemissions,
coalpowerplantoperations,vehicularfossilfuelcombustion,
andagriculturalbiomassburning(ABB).Academicresearchers
in China who conducted studies about the severe haze
situation in Beijing and northern China, have defined seven
majorfineaerosolparticlescommonlyfoundinhaze–namely
mineral,soot,organicmatter,flyash,K-rich,S-richandmetal
particles (Lietal,2010).Notably, theirstudies indicated that
theageingofsootparticlesfromABBinahighrelativehumidity
environmentincreasedtheabsorptionofvisiblesolarradiation
ascomparedtosootalone.
Attenuationduetohazeisverycomplexbecauseofdiversity
intheparticletype,size,shapeandsizedistributioninahazy
atmosphere.Ingeneral,hazeattenuatesvisibleradiationmore
than it attenuates IR radiationdue to the small sizeof haze
particles.This isbecause thesmalldiameterof theparticles
typically coincides with the short wavelengths found in the
visibleportionoftheEMspectrum.Scatteringisthedominant
attenuation factor. However, in regions with high relative
humidity, aerosol liquid water absorption can increase as
moisturecancondenseontheparticles.Experimentalstudies
haveshownthatattenuationatlongerwavelengthsislessthan
thatatshorterwavelengths.Hence,IRsensorscanpenetrate
further through haze than visible optical sensors. Figure 2
showsthephotographstakeninSingaporeonacleardayand
onahazydayin2013.
Specific to Southeast Asia (SEA) is the recurring biomass
burning-inducedsmokehaze.TheparticlesintheSEAhazeare
contributedprimarilybyforestfiresburninginIndonesia.This
isdifferentfromtheparticlescontributedbyanamalgamation
of sources, including industrial emissions, coal power plant
operations and vehicular fossil fuel combustion on top of
Figure2.DaytimephotographshowingBedokSouthAve1,lookingwesttowardsMarineParadeat12:04pmon24June2013(left)(©Wolcott/File:MarineParadeRoad(2).jpg/WikimediaCommons/CCBy3.0)andviewfromthesame
vantagepointon21June2013at10:35am,whenthehazewasathazardouslevels(right)(©Wolcott/File:HazeobscuringMarineParade.jpg/WikimediaCommons/CCBy3.0).
85DSTA HORIZONS | 2015
ABBinnorthernChinathatresulted inthepersistenthaze in
Beijing.oneoftheSEA’sworstairpollutioneventstookplace
inJune2013whenthe three-hourPollutionStandards Index
(PSI) inSingapore reacheda recordhighof401on21June
2013.Figure3illustratestheseverityofthehaze’simpacton
visibilitywhenthePSIreached312.
Studies by local academic researchers noted that the
concentrations of particulate matter of 2.5µm size (PM2.5)
increasedmore than15 timesduring thehaze inJune2013
ascomparedwithnon-hazeperiods.Toexploretheparticles’
interactionwithlight,theopticalpropertiesofambientaerosols
wereexaminedintermsofbap,thelightabsorptioncoefficient
ofparticles,aswellasbsp, the lightscatteringcoefficientof
particles. Itwas found that PM2.5wasmore correlatedwith
bsp than bap. This implied that attenuation by PM2.5 was
mainly due to the scattering of light by the particles (See,
Balasuhramanian,&Wong,2006).
The studies also reported that fine particles were generally
found ingreatermassconcentration thancoarseparticles in
ourlocalenvironment.Aninterestingobservationmadeduring
hazydayswas thatwhile themass concentration increased
across theentiresize range, the increase incoarseparticles
was larger than in fine particles. A possible reason for this
couldbethatwhilebiomassburninginIndonesiaemittedmore
fineparticlesthancoarseparticles,someofthefineparticles
amalgamated to formcoarseparticlesduring the long range
transporttoSingapore.
Figure3.Daytimephotographofatrafficjunctiontakenfrom1km(left)andcloserangeof50m(right)whenthePSIreached312inJune2013.
In summary, the increase inparticles,particularly thosewith
diameter similar to thewavelength of light, is thought to be
responsibleforvisibilityimpairmentonhazydays.Sincevisible
light would be more strongly attenuated, IR sensors would
performbetterundersuchconditions.However,thescattering
andabsorptioncoefficientsofhazeparticlesincreaseastheir
concentrations increase. This could reduce theperformance
of even IR sensors, as the wavelengths at which they are
operatingcouldalsobeseverelyattenuated.
EMERGING TECHNOLOGIES FOR FURTHER CONSIDERATION
Localenvironmentaleffectsaffectsensorperformance,albeit
to different extents on different wavelengths. Multispectral
or hyperspectral detection technologies could potentially
reducesensorperformancedegradationbyapplyingspectral
signature analysis across multiple wavelengths. In addition,
sensingintheshortwaveIR(SWIR)portionoftheEMspectrum
(wavelengthsfrom0.9to1.7microns)hasrecentlybeenmade
viable with the maturity of IngaAs sensors. Image fusion
and enhancement techniques are examined in the following
sections.
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86 DSTA HORIZONS | 2015
MultispectralandHyperspectralSensors
Multispectralsensorsdetectthewavelengthsacrossdifferent
bands in the EM spectrum. The spectral signature of the
detectedtargetisthencomparedtothoseofknowntargetsto
determineifthereisamatch.Similarly,hyperspectralsensors
create a larger number of images from contiguous, rather
than disjointed regions of the EM spectrum, typically with
muchfinerresolution.Thefinerresolutionprovidesadditional
informationforthespectralsignatureanalysis(Renhornetal,
2013).Studieshaveshown that suchsensorscouldprovide
significant improvement in target detection performance as
well as improve false alarm performance over single-band
sensors.Thechallenge,however, is the requirement tobuild
acomprehensivedatabaseofthetargets’spectralsignatures
forcomparisonduringtheanalysis.onedevelopmentthathas
potentiallyspedupthedevelopmentofviablemultispectraland
hyperspectralsensors istheQuantumWell IRPhotodetector
(QWIP).
The QWIP typically consists of multiple quantum wells
sandwiched between its emitter and collector contacts
(Ting et al, 2014). By adjusting the width and depth of
the well, the sub-band transition energy and absorption
wavelength can be adjusted. The gallium arsenide-based
or aluminium gallium arsenide-based QWIP stands out
as a prime candidate for the development of Focal Plane
Arrays (FPA)due to its favourable inherentproperties.These
include its ease of fabrication, ruggedness, pixel-to-pixel
uniformity, high pixel operability, temporal stability and its
abilitytobetailoredtotheselectedwavelengths.Todate,the
industry has demonstrated themegapixel single band LWIR
QWIP FPA, simultaneous dual-band megapixel QWIP FPA,
640x512 formatspatiallyseparated four-bandFPA,aswell
asthedevelopmentofasuper-pixelQWIPFPAforanimaging
multiple wave band temperature sensor. The next bound of
development is expected to focus on harnessing the QWIP
FPAtechnologyforacompact7.5µmto12µmhyperspectral
IRimager.
ShortwaveInfraredSensors
In recent years, SWIR has grown to become a viable low
light imagingoptiontoovercomeenvironmentaleffectssuch
as haze, fog and dust for mission scenarios, where target
detailsarehighlyvaluedbutdonotshowuponMWIRorLWIR
sensorsduetonon-representationbytemperaturedifferences.
ASWIRsystemcantypicallyprovidebetterspatialresolution
thanasimilarclassMWIRorLWIRsystem,enhancingtarget
recognition and identificationwhich are critical functions on
thebattlefieldtominimisecollateraldamage.Whenoperated
at night, SWIR can also take advantage of an atmospheric
phenomenon called night sky radiance or night glow,which
emitsfivetoseventimesmoreilluminationthanstarlight,and
nearly all in the SWIR wavelengths. These wavelengths are
relativelycovertastheyareundetectablebyvisiblespectrum
cameras, II-basednightvisiondevicesaswellasMWIRand
LWIR cameras. In addition, SWIR also allows surveillance
throughglasswindowswhichMWIRandLWIRcamerasare
unabletopenetrate.
ImageFusionandEnhancementTechniques
Recent global geo-political activities have escalated the
urgent need to deploy multiple imaging sensors operating
across different spectral bands to provide timely anomaly
detection. Surveillance agencies now require situation
pictures from multiple sensors to reach their command
centres simultaneously. The use of effective image fusion
techniques would: (a) maximise the amount of relevant
informationthatisdeliveredtotheoperator;(b)cutdownthe
timespentonirrelevantdetails(e.g.falsealarms),uncertainty
and redundancy in the output; (c) prevent the occurrence
of artefacts or inconsistencies in the fused image; and
(d)suppress irrelevant featuressuchasdistortioncausedby
noisefoundinthesourceimages.Inaddition,fusedimagerythat
optimallyagreeswithhumancognitionprocessesallows the
humanoperatortograspthegistofthedisplayedinformation
quicklyandexecuteefficientandeffectiveresponsesfortime-
critical surveillancemissions.over the years,multiple smart
processing and target tracking algorithms, including edge
detection,autonomousvideomotiondetectionand tracking,
havebeendevelopedandintegratedwiththecentraldisplay
interfaceofmultiplesensorfeeds.Thishasgreatlyenhanced
collectivesurveillanceefforts.
Fused imagery has traditionally been represented in grey or
monochromatictones,duepartlytotheoutputdisplaysofthe
IRimagingsensors.Whilethehumaneyecanonlydistinguish
about100shadesofgreyatany instant, IR imagingsensors
produced in the industry today can discriminate between
severalthousandsofcolours.Theuseofcolour imagesmay
improve feature contrast and reduce visual clutter, enabling
better scene segmentation, object detection and depth
perception. This will also yield a more complete mental
representationoftheperceivedsceneforenhancedsituational
awareness.
87DSTA HORIZONS | 2015
Researchinthisfieldisongoing.Intime,thesedevelopments
will mature and systems could be deployed in the field for
improvedwideareasituationawareness.Thehigherprobability
of targetdetection, recognitionand identificationwouldalso
drivetheoptimisationofautomaticsurveillancesystemsand
alleviatemanpowerconstraintsfacedbynationalsecurityand
defenceentitiesregionallyandglobally.
CONCLUSION
Eo sensors play a critical role in detecting and identifying
targets in modern day battlefields. However, they can be
affectedbyenvironmentalconditions.Inourlocalenvironment,
the presence of water vapour due to high humidity, rainfall,
cloudsorfog,canseverelyimpactthesensors’performance.
Itisthususefultounderstandtheoperationalrequirementsof
the sensors and the environmental conditions inwhich they
operate, inorder to select themostoptimumsensor for the
situation.
REFERENCES
Anon. (1993). Protecting visibility in national parks and
wildernessareas.NationalResearchCouncil,Washington,DC.
Bernard,E.,Riviere,N.,Renaudat,M.,guiset,P.,Pealat,M.,
& Zenou, E. (2013). Experiments and models of active and
thermalimagingunderbadweatherconditions.Proceedingsof
SPIE,Electro-OpticalRemoteSensing,PhotonicTechnologies,
andApplicationsVII;andMilitaryApplicationsinHyperspectral
Imaging and High Spatial Resolution Sensing, 8897. doi:
10.1117/12.2028978
Chen,C.C. (1975).Attenuation of electromagnetic radiation
byhaze,fog,clouds,andrain.(RANDReportNo.R-1694-PR)
Retrieved from http://www.rand.org/content/dam/rand/pubs/
reports/2006/R1694.pdf
Eismann,M.T.,Schwartz,C.R.,Cederquist,J.N.,Hackwell,
J.A.,&Huppi,R.J. (1996).Comparisonof infrared imaging
hyperspectralsensorsformilitarytargetdetectionapplications.
Proceedings of SPIE Imaging Spectrometry II, 2891(91).
doi:10.1117/12.258056
Leong,S.C.,&Foo,y.C. (2007,December).Singaporerain
ratedistributions.6thInternationalConferenceonInformation,
Communications & Signal Processing, 2007. doi: 10.1109/
ICICS.2007.4449534
Li,W. J., Shao, L.y., & Buseck, P. R. (2010). Haze types in
Beijing and the influence of agricultural biomass burning.
AtmosphericChemistryandPhysics,10(17),8119–8130.doi:
10.5194/acp-10-8119-2010
Malm, W. C. (1999). Introduction to Visibility. National Park
Service and Colorado State Institute for Research on the
Atmosphere,FortCollins,Colorado.
Renhorn, I. et al. (2013). Hyperspectral reconnaissance in
urbanenvironment.ProceedingsofSPIE,InfraredTechnology
andApplicationsXXXIX,8704.doi:10.1117/12.2019348
See,S.W.,Balasuhramanian,R.,&Wang,W.(2006).Astudy
of the physical, chemical, and optical properties of ambient
aerosolparticles inSoutheastAsiaduringhazyandnonhazy
days. Journal of Geophysical Research Atmospheres,
111(D10S08).doi:10.1029/2005JD006180
Ting, D. Z., Soibel, A., Keo, S. A., Rafol, S. B.,Mumolo, J.
M., Liu, J. K., … gunapala, S. D. (2014). Development of
quantumwell,quantumdot,and type II superlattice infrared
photodetectors. Journal of Applied Remote Sensing, 8(1).
doi:10.1117/1.JRS.8.084998
Wolcott. (2013). File:Haze obscuring Marine Parade.jpg. In
WikimediaCommons.RetrievedMarch10,2015,fromhttp://
commons.wikimedia.org/wiki/File:Haze_obscuring_Marine_
Parade.JPg#mediaviewer/File:Haze_obscuring_Marine_
Parade.jpg
Wolcott. (2013). File:Marine Parade Road (2).jpg. In
WikimediaCommons.RetrievedfromMarch10,2015,http://
commons.wikimedia.org/wiki/File:Marine_Parade_Road_(2).
JPg#mediaviewer/File:Marine_Parade_Road_(2).jpg
PERFoRMANCECHALLENgESFoRHIgHRESoLuTIoNIMAgINgSENSoRSFoRSuRVEILLANCEINTRoPICALENVIRoNMENT
88 DSTA HORIZONS | 2015
BIOGRAPHY
LEE Cheow Gim is a Project Lead
(AdvancedSystems)whomanageselectro-
optical(Eo)projectsfortheSingaporeArmy.
HegraduatedwithaBachelorofEngineering
(Electrical and Electronic Engineering)
degree from Nanyang Technological
university(NTu)in2003.
EE Kok Tiong is a Project Manager
(Advanced Systems) who manages Eo
projectsfortheRepublicofSingaporeNavy.
HegraduatedwithaBachelorofEngineering
(Electrical Engineering) degree from the
National university of Singapore (NuS) in
2002 and a Master of Science degree in
ElectricalEngineering(ComputerNetworks)
fromtheuniversityofSouthernCalifornia,uSA,in2008.
HENGYinghui Elizabeth is a Programme
Manager (Advanced Systems) who
overseesEoprojectsacrosstheSingapore
Armed Forces. She graduated with a
Bachelor of Engineering (Electrical and
Electronic Engineering) degree from NTu
in 2003. She also obtained a Master of
Science(ElectricalEngineering)degreefrom
theNaval Postgraduate School, uSA, and aMaster of Science
(DefenceTechnologyandSystems)degreefromTemasekDefence
SystemsInstitutein2013.
89DSTA HORIZONS | 2015
PERFoRMANCECHALLENgESFoRHIgHRESoLuTIoNIMAgINgSENSoRSFoRSuRVEILLANCEINTRoPICALENVIRoNMENT
90 DSTA HORIZONS | 2015
SAFETyMANAgEMENToFNATIoNALDAyPARADEFIREWoRKSDISPLAy
INTRODUCTION
SIMGimYoung,LEEChungKiat,OEISuCheok,ME5ONGWoeiLeng
ABSTRACT
ThefireworksdisplayisahighlightofeveryNationalDayParade(NDP)inSingapore.Thedriveforamorespectacularandintimatefireworksexperience increases the importanceplacedon thesafetyofperformersandspectators.Thisarticledescribesthechallengesinmanagingthesafetyoffireworks.Itstartsbyintroducingthecharacteristicsoffireworksanditssafetymanagementapproaches,followedbyanexplanationofhowsafetyisaddressedthroughthefireworkslifecycle–fromproductdesigntotransportation,storage,installation,initiationanddisposal.Finally,thearticlesharesinnovativesolutionsused tocontrol the safetydistanceof fireworks.Theeventualoutcomeof theseapproaches is a safeandspectacularfireworksdisplayforNDP.
Keywords:fireworks,safety,NationalDayParade,NDP
Figure1.NDPFireworksDisplay,2014
91DSTA HORIZONS | 2015
on 9 August each year, Singaporeans come together to
celebratethenation’sindependence.TheNationalDayParade
(NDP)featuresmassperformances,aceremonialparadeand
multimedia displays that depict Singapore’s cultures and
values. The fireworks display is a highlight of theNDP (see
Figure1).
At everyNDP, a FireworksCommittee comprisingpersonnel
from theSingaporeArmedForcesAmmunitionCommand is
formedunder theNDPExecutiveCommittee toorganise the
fireworks display. This committee specifies the performance
andsafety requirements tobe implementedby thefireworks
contractor.
While the displays are highly entertaining, fireworks are
explosives and need to be treated with the appropriate
safetyprotocol.Assuch, theFireworksSystemSafetyTeam
comprising members from the Fireworks Committee and
DSTA’s armament safety specialistswork together to review
and ensure fireworks safety duringNDPs. The team adopts
a systemsafetyperspective1 toassess thehazardsof each
fireworkactivityandrecommendssafetymeasurestominimise
therisks.Thisconceptwasinitiatedintheearly1960sinthe
aerospace industryand isaneffectivewayofanalysingand
managingsafetyrisksholistically.
FUNDAMENTALS OF FIREWORKS
Fireworkswere invented inChina in the seventhcentury. Its
applications have since spread to other parts of the world
andhavebeenintegralinmanycelebrations.Despiteitslong
history, fundamentals of fireworks displays have remained
largely thesameover time.Aerialshells,mines,cometsand
variantsformthemaindisplaycomponents.Fireworkscanbe
classifiedbroadlyintotwomaingroups.
The first group, aerial shells, is builtwith a time fuse, lifting
charge, bursting charge and pyrotechnic chemicals. Aerial
shells are launched from mortar tubes into the sky using
gunpowderasaliftingchargebeforeburstingintodisplaysof
brilliant andcolourful lights.Thebrilliant coloursarecreated
from the combustion of metallic powders. The appearance,
component and effects of an aerial shell are illustrated in
Figure2.
Figure2.Aerialshell
AerialShell CrossSection Effects
92 DSTA HORIZONS | 2015
The second group comprises only lifting charge and
pyrotechnic chemicals. The effects are ejected from the
ground upon ignition. Examples are comets and mines as
showninFigure3.Bothtypesoffireworkscanbecustomised
toproducedifferentcolours,patternsandbrilliance.
CHALLENGES
The NDP fireworks display is the largest fireworks event
in Singapore and an important component of the parade’s
choreography.Thereareseveralrehearsals leadinguptothe
final event, and anymishaps would have significant impact
duetothefireworks’proximitytoperformersandspectators.
Therefore, the safety review of NDP fireworks display is
important to ensure safety of the public, performers and
fireworkstechnicianswhilemeetingthedemandsoftheparade.
Thenumerousstakeholders, regulationsandsiteconstraints
(includingweatherconditions)addtothecomplexity.Fromthe
start,theteamaddressestheintrinsicsafetyofthefireworks
productanditscompliancewithregulatoryrequirements.The
teamreviewstheindustrysafetypracticesconstantlyduringthe
preparation,setupanddisplayofthefireworks.Theestablished
safety codes of theUSNational Fire Protection Association
for Display of Fireworks and British Pyrotechnic Association
serveasbaselinesafetyrequirements.TheSingaporeArmed
Forces(SAF)andDSTAalsoengageestablishedpractitioners
to provide training to reinforce understanding and ensure
alignmentwithbestpractices.
Figure3.Cometsandmines
CometsandMines EffectsofComet EffectsofMine
ENSURING PRODUCT SAFETY
Fireworks must be designed and constructed to be safe
duringhandling,transportationanduse.InMay2000,afatal
explosion occurred during a fireworks display at Bray Park,
Australia.Threegroundfireworksexplodedand ruptured the
steellaunchertube,leadingtoonefatalityandseveninjuries.
Theinvestigationconcludedthatthefireworksmalfunctioned.
Theexplosioneffectwasworsenedbyitsconfinementwithin
thesteeltubes.
The teamensuresproductsafetybysourcingfireworks from
reputable manufacturers with strong safety track records
of supplying fireworks to major international events. The
team also requires themanufacturer to be certified by their
local authority and registeredwith auSbased independent
auditor – the American Fireworks Standards Laboratory
(American Fireworks Standards Laboratory, 2011). The
manufacturer must also be ISo 9001 Quality Management
System compliant. Furthermore, the team conducts factory
assessmentstoobservetheproductionprocessandtestthe
productperformanceandsafetyfeaturesofthefireworks.
93DSTA HORIZONS | 2015
HAZARD CLASSIFICATION OF FIREWORKS
In 2000, the Netherlands had a major fireworks accident
within the city of Enschede. The fireworks explosions were
equivalentto4000kgto5000kgofhighexplosives2.Itresulted
indamageamountingtomorethan€450million.Thisincident
was a stark reminder that fireworks could behave like high
explosives,andresultedinareviewofthehazardclassification
offireworks.Theuseofcorrecthazardclassificationenables
appropriate safety protocols to be enforced during storage
andtransportation.In2005,theunitedNations(uN)published
amethod todetermine thehazardclassificationoffireworks
basedonchemicalcomposition.
The fireworks classification system assigns the hazard
categoryoffireworksbasedontwokeycriteria:thediameter
ofthefireworksandtheproportionofflashcompositionused
inthefireworks.Flashcompositionisamixtureofpyrotechnics
chemicals that reactsmorevigorously toproduceabursting
orexplosioneffect.Ittypicallyconsistsofanoxidiser,anon-
metallic fuel and ametallic fuel. An excessive proportion of
flashcompositioninfireworkswillresultinaviolentexplosionin
theeventofanaccident.Thediameteroffireworksdetermines
the mass of pyrotechnics chemical that will combust
instantaneously. As the diameter increases, the combustion
effect becomesgreater and can increase the likelihoodof a
violentexplosion.
Figure4.Bargeforfiringaerialfireworks,2014
usingtheuNfireworksclassificationsystem,theteamreviewed
the chemical composition of all fireworks used in NDP and
identified thosewhichcanpotentiallyexplode if anaccident
occurred during storage or transportation (Russell, 2009).
These items were isolated and stored with sufficient safety
distancestothesurroundingsites.Theywerealsotransported
separatelyandprepared topreventsympatheticexplosions3
shouldanaccidentoccur.Atthefiringsite,theywereinstalled
into the launching tubes at the earliest opportunity so that
accidental ignition would launch the fireworks into the sky
instead of causing an explosion of stacked fireworks (see
Figure4).
SAFE DEPLOYMENT
Fireworks are stored in licensed explosive storehouses in
Singapore.Beforeeachdisplay, thefireworksareunpacked,
inspectedandmovedtothefiringlocations.Thefiringcircuits
aretheninstalledandtested.SinceNDP2011,fireworkshave
been launched from a barge inMarina Bay and around the
floating platform. There were also fireworks launched from
performers’personalequipmentlikemotorcyclesandtorches.
Figure5illustratesthesettingupofaerialshellsatthebarge.
Thesurroundingsarecheckedaftereachdisplayforfireworks
thathavefailedtolaunchordroppedprematurely.Thecause
of each defect is investigated and the faulty fireworks are
disposedof.
SAFETyMANAgEMENToFNATIoNALDAyPARADEFIREWoRKSDISPLAy
94 DSTA HORIZONS | 2015
SPECTATORS SAFETY
Fireworks produce debris that could hurt people within the
vicinity(seeFigure6).
There could also be fallout hazards from malfunctioning
fireworkssuchas theburstingofaerialshellson theground
aftertheyfailtoigniteintheairandtheimpropermountingof
fireworksleadingtothewrongorientationwhenfired.
Figure5.Workflowofaerialshellsatbarge
Figure6.Examplesofdebrisfromfireworks
CardboardBaseofShell PlasticWhistlingComponent CardboardDebrisofComet
95DSTA HORIZONS | 2015
of fireworks shells (see Figure 8). The wind conditions are
monitoredinrealtimeandthecommitteecaninhibitselected
fireworks if thewindspeedanddirectionthreatentoexceed
the safe limits. This ensures that fireworks displays remain
safe for the performers and spectators around the barge at
alltimes.
In addition, the team ensures that all materials used in the
constructionof theaerial shell arecombustible.Mostof the
materialwillbeburnedtoashesduringtheburstingoftheaerial
shell,minimising the amount of debris falling to theground.
Theinstallationandpositioningoffireworksmortartubesare
alsoscrutinisedtomitigatethehazardoflaunchingtheshells
intothespectators.
Figure7.Possiblefalloutdistanceatvariouswindspeeds
The team reviewed internationalbestpractices todetermine
the optimal safety distance and adopted the uK approach
whichcalculatesthesafetydistancebasedonvariousfactors
at each fireworks display scenario (Smith, 2011). The aerial
shellsafetydistanceconsidersthesizeoffireworks,firingangle
andwindconditions.Thesizeofanaerialshelldeterminesthe
launchvelocityandair-burstdiameter.Thefiringangle,wind
directionandwindspeedwoulddeterminethetrajectoryofthe
aerialshellduringtheinitialflightandthedispersionofdebris
aftertheair-burst.
Theteamalsodevelopedawindchart tohelptheFireworks
Committee address the impact of different wind conditions
on thesafetydistance (seeFigure7).Thewindchartshows
themaximumwindspeedineachdirectionfordifferentsizes
SAFETyMANAgEMENToFNATIoNALDAyPARADEFIREWoRKSDISPLAy
96 DSTA HORIZONS | 2015
PERFORMERS SAFETY
Fireworksareusedbyperformersinseveralsegmentsofthe
NDPaspyrotechnicprops.In2012,thesesegmentsincluded
the Singapore Soka Association performance, SAF Military
Police precision drills and motorbikes ride-past. To ensure
performers’ safety, the team participated actively in the
choreographies so that the fundamental safety principle of
maintainingsafetydistanceisintegratedintotheperformances.
Forperformancesthatrequirehand-heldpyrotechnictorches,
fireworksthatdonotigniteclothingareused.Theperformers
are equipped with protective eyewear, headgear and fire-
resistant clothing to further mitigate the risk of burns. The
team also worked with the show choreographer to ensure
that the amount of fireworks required to meet performance
requirementswaskepttoaminimum.
Thepyrotechnicstorchwasdesignedtoensurethatitsparts
donothurtperformers.Thefiringcircuitforthepyrotechnics
torch incorporatedmaster and safety switches. This design
required theperformer tomake twosimultaneousactions to
ignitethefireworkseffectsoastoavoidaccidentalignition.
SYSTEM SAFETY APPROACH
The team took a system safety approach to ensure and
enhance safety in dealingwith the fireworks effectively. The
priority was to use safe configurations (through appropriate
safetydesignprotocols)beforeprovidingprotectivedevices,
warning devices and relying on procedures. Some of the
considerationstakenduringtheNDPillustratethisapproach.
a) Display Design and Configuration – During the grand
finalewhichtakesplaceattheplatformandspectatorstand,
mines and comets are fired away from spectators and
performers.onlyfireworkswithouthazardousdebrisareused
onstage.Performersareallowedtouseonlyfireworkswhich
produceharmlesssparks.
b) Protection-Performersputongogglesandfire-resistant
costumes to furthermitigate the risksofburns.Partsof the
stagewhichareaffectedbysmoulderingdebrisareconstructed
withfire-resistantmaterials.
Figure8.WindchartaroundhighlevelbargeinMarinaBay,2014
97DSTA HORIZONS | 2015
c) Warning - A monitoring device is used to measure the
wind speed and direction throughout the show.Whenwind
conditionsexceedsafelimits,thefiringofselectaerialshells
wouldbecurbed.
d) Procedures - Fireworks safety distances are integral to
the choreography of the show. The control tower monitors
performers’ complianceandcanceasefiring in theeventof
deviation.
The four levels of risk mitigation are standard observations
ofthesystemsafetyapproach.
RISK ENDORSEMENT AND ACCEPTANCE
AMinistryofDefenceSafetyBoardassessestherisksposed
by NDP fireworks in accordance with the risk management
frameworkestablishedforNDPfireworksdisplay.Theresidual
risks,whicharereducedtoaslowasreasonablypracticable,
are then accepted by the NDP Executive Committee.
Subsequently, the teammonitors the fireworks performance
duringeachrehearsalandontheactualparadetoensurethat
thecontrolmeasuresareeffective.
CONCLUSION
The team recognises the benefits of the systematic hazard
identification and risk management approach in managing
the complex demands of the NDP fireworks display. It has
adaptedsafetyknowledgeonmilitaryexplosivesforfireworks
displaysuccessfully.Thesafetycontrols imposedonmilitary
explosives are usedwhen applicable to enhance the safety
ofstorage, transportation,preparation,firinganddisposalof
commercialfireworks.
The system safety approach enables the team to identify
possible hazards that are beyond product safety and
regulations. It allows the team to prescribe measures to
minimise risks to the public, performers and fireworks
technicians. This ensures safe fireworks displays during all
NDPs,fromrehearsalstothegrandfinaleonNationalDay.
ACKNOWLEDGEMENTS
TheauthorswouldliketothankMryenChongLian(retiredin
2014),ME6oliverLanChiWai,ME6AdrianLimBengBoon
and ME6 Cheong Heng Wan for contributing to the safety
practicesforNDP2012,NDP2013andNDP2014.
REFERENCES
American Fireworks Standards Laboratory. (2011). AFSL
standardsfordisplayfireworks.Bethesda,MD:Author.
Russell, M. S. (2009). The chemistry of fireworks (2nd ed.).
Cambridge,uK:RoyalSocietyofChemistry.
Smith, T. (2011). Firework displays: explosive entertainment.
uS:ChemicalPublishingCompany.
ENDNOTES
1 Systemsafetyperspectivemeansthesafetyreviewofthe
interfacesamongthefireworksproducts,displaysites,display
operators, equipment, installation, weather, NDP performers
andthegeneralpublic.
2 Highexplosivesaresubstancesormixtureof substances
whichcandetonateundernormalconditions.
3 Sympatheticexplosion is thesimultaneous initiationofan
explosivechargebyanearbyexplosion.
SAFETyMANAgEMENToFNATIoNALDAyPARADEFIREWoRKSDISPLAy
98 DSTA HORIZONS | 2015
ME5 ONG Woei Leng is one of the
Commanding officers of SAF Ammunition
Command. He is responsible for the safe
storage and maintenance of ammunitions
kept in the depot as well as the daily
operationsofthedepot.Hewaspreviously
astaffofficerintheExplosiveSafetyBranch
in the SAFAmmunitionCommand. As the
DeputyChiefSafetyofficerandChiefSafetyofficerforNDP2011
and 2012 respectively,Woei Leng ensured the safe conduct of
thefireworksdisplayduringtheshows. InNDP2014,heserved
astheDeputyChairmanoftheFireworksCommittee.WoeiLeng
graduatedwithaBachelorofArts (Psychology)degree fromthe
EdithCowanuniversity,Australia,in2010.
BIOGRAPHY
SIM Gim Young is a System Manager
(Systems Management) managing the
operationsandsupport for explosivesand
pyrotechnicsintheSingaporeArmedForces
(SAF). In 2013and2014, he led theDSTA
team supporting the National Day Parade
(NDP) Fireworks Committee in assessing
the safety of fireworks display. He also
conducts quantitative risk assessments on explosive sites and
advises on the riskmitigationmeasures. gim young graduated
withaBachelorofEngineering (MechanicalEngineering)degree
fromNanyangTechnologicaluniversityin2008.
LEEChungKiatisHeadExplosivesSafety
(Systems Management). He is a licensed
authorityonmilitaryexplosivefacilitiesand
advisestheSAFonexplosivesstorageand
transport safety. He is also the Chairman
of the Explosives Safety Technical Sub-
CommitteeofExplosivesFireandChemical
Safety Committee. Chung Kiat graduated
withaMasterofScience(ExplosiveordnanceEngineering)degree
fromCranfielduniversity,uKin2005.
OEISuCheokisaSeniorPrincipalEngineer
(Systems Management). He develops and
implementsthesafetymanagementsystem
for DSTA and the Ministry of Defence
(MINDEF).Healso supports systemsafety
analysis efforts to enhance safety through
riskmitigation.SuCheokextendshissafety
management competence beyond DSTA
inhis rolesas secretariat ofMINDEF’sWeaponSystemsSafety
Advisory Board as well as an executive committee member of
the InternationalSystemSafetySociety (SingaporeChapter).He
graduatedwithaBachelorofEngineering(ChemicalEngineering)
degreefromtheNationaluniversityofSingaporein1985.
99DSTA HORIZONS | 2015
SAFETyMANAgEMENToFNATIoNALDAyPARADEFIREWoRKSDISPLAy
100 DSTA HORIZONS | 2015
PRoTECTIoNANDRESILIENCyFoRSINgAPoRE’SCRITICALINFRASTRuCTuRES
INTRODUCTION
AfterSingaporegainedindependencein1965,itwasnecessary
tobuilduplocalprotectivedesigncapabilitiesquicklyforthe
development of key installations, defence infrastructure and
facilities. Early protective designmethodologieswere based
onprotectionagainstwell-prescribedthreats.Thesebuilding
designs were standardised and often replicated for greater
developmental efficiency. The building design philosophy
was tofirstspecify thedesign-basis threat–comprising the
weaponandstand-off,andthentodesignthebuildingbased
onspecificprotectioncriteria.Thesecriteriawereoftenrelated
to specific building responses to weapons threats, with the
assumptionthatallcriticalcontentswithinthebuildingwould
havesimilardamagethresholds.
Whilethisdesignphilosophywasadequateinthepast,society
hasseenrapidchanges,especiallyoverthelastthreedecades.
ONGKweeSiangSteve,CHONGOiYinKaren,SEEThongHwee
ABSTRACT
Theapproach todesigningcritical infrastructureso that theyareprotectedagainstdiscreteandwell-defined threats isgenerallywell understood.However, in the faceof asymmetrical threats and vague terrorist intentions, suchprotectivedesignapproachesareoflimiteduse.Theincreasingconnectivityandcomplexitiesofmodernsocietycancompoundtheproblem,thuscausingunintendedconsequences.Itisthereforenecessarytorethinkhowcriticalinfrastructuresshouldbesecured.
ThisarticledrawsfromDSTA’sexperienceindesigningcriticalinfrastructuresfortheMinistryofDefenceandtheSingaporeArmedForces.Itillustrateshowprotectionandresiliencycanbebalancedtoimprovethesurvivabilityofcriticalinfrastructures,taking into account system connectivity, vulnerabilities and themeans to enhance recovery. Diagrams are provided toillustrate ways to integrate R&D and findings from international collaborations in Protective Technology into designingforresiliency.Examplesofnumericalsimulationsandexplosivetestsarealsousedtodemonstratethenecessaryvigourneededintestingassumptions,validatingconceptsanddevelopinganimplementablesolution.Thisarticleemphasisesthatthoroughandresponsibleprotectivetechnologyworkmustbenestedwithinrealistictestsandrelevantexperience.
Keywords:protectionandresiliency,criticalinfrastructures,connectivity,survivability,protectivedesign
Advances in technology have resulted in globalisation and
increasedconnectivitythathavealsochangedthethreatspace.
These new realities call for a reviewof thewaySingapore’s
criticalinfrastructuresareprotected.
THE RISE IN MODERN SYSTEMS COMPLEXITY
The advent of the computer sparked rapid advances in
technology, enabling product research, development and
prototyping within a virtual environment. This reduced
developmentaltimeandcostsgreatly.Coupledwiththegrowth
of the Internet, the development ofwireless and broadband
technologiescatalysedthegrowthofinformationtechnology,
expanding network access. This has resulted in higher
demandsforinformationexchangeanddataconnectivity.
101DSTA HORIZONS | 2015
Theneedtocompetegloballyfurtherdrovethedevelopment
ofinterconnectedinfrastructuresystemstomeetproductivity
goals.Mostsystemstodayaredesignedto integrateasone
networktodelivercapabilitiesandhavebecomemorecomplex
as a result. This interconnectedness alsomeans that failure
in one component can result in cascading failures in other
systems clusters. New threats, such as cyber attacks, have
alsosproutedandgrown.Againstthisbackdrop,newrealities
thatchallengethewaycritical infrastructuresaretraditionally
protected have emerged. Where people, critical equipment
andfunctionswereoncehoused indiscretecritical facilities,
theyarenowhousedinconnectednetworksoffacilities.
NEW REALITIES - CHANGING THREATS AND EVOLVING NETWORKS
WhatWasDesignedinthePastMayNotBeRelevantToday…ThreatsHaveChangedandOften,WhatCountsareNetworksofThingsRatherThanStandaloneFacilities
The threats that protective buildings and infrastructurewere
designedagainstinthepasthavechanged.Theearlytypesof
weaponscompriseddifferentcategoriesofartilleryand‘dumb’
weaponsthatwereairdropped.Thismethodwasinaccurate
and had limited penetration capabilities and range. Modern
weaponrynowrangesfromguidedweaponsthatcanbefired
fromlongerdistances,tomasssaturationthreatsfromrockets,
artilleryandmissiles.Warheadtechnologyhasadvancedwith
morepowerfulexplosivesaswellasdifferentkillmechanisms
suchasshapedcharges,runwaydenialrounds,fragmentation
rounds and thermobaric charges. Fuse technology has also
progressed to facilitate the development of penetrating
warheads. These weapons of enhanced capabilities can be
developedfaster,makingitharderforprotectiveinfrastructures
to keep up with commensurate protection levels without
overwhelming costs and disruptions to operations. Adding
to this ever-evolving andwide spectrumofmodernweapon
threatsistheneedforcriticalfunctionstooperateinnetworks
ofbuildingsandinfrastructure.Thisgivesrisetothequestion
ofwhether the traditional approach to protective designwill
becomeobsoleteinthefuture.
Increasingly,ItIsWorldwideConnectivityThatEmboldensAdversaries
Beyondspurringmilitaryweaponstechnologydevelopments,
worldwideconnectivityhasincreasinglyemboldenedterrorist
activities,spinningoffemergentthreats.Terrorismhasevolved
over the years, from onewhere therewas little connectivity
andwhereknowledgeinbombmakingwasconfinedtoafew,
toahighlyconnectedenvironmentwheredecentralised,non-
hierarchal leadershipscollaborate, tapand share knowledge
onlineeasily.Furthermore,suchdecentralisedbutconnected
terrorist networks have become harder to detect. Terrorist
organisationshavethusturnedthethreatofincreasedexposure
due to the use of the Internet and telecommunications into
opportunitiestobetterthemselvesandtheiroperations.
UnintendedConsequencesCanAriseFromEver-EvolvingThreats
Threats and their effects have becomemore unpredictable.
Theresultingcomplexconsequencesmaynotbeanticipated
during the design phase. The September 11 attacks on the
World Trade Centre (WTC) and the Pentagon in 2001 used
civilianaircraftasaweapon.WhiletheWTCtwintowerswere
designedtowithstandaircraft impactanddidso initially, the
eventualcollapseofthetowersarosefromthelargemagnitude
of aviation fuel fires that weakened the building structure.
Thus,thedesignofinfrastructurehastoconsiderawiderange
ofpotentialthreats.
TheRangeofPotentialTargetsCanSpikeDramatically
Traditionally, the focus has been on the protection of key
installations and not on soft targets. The Bali bombings in
2002, aswell as the JWMarriot andRitzCarltonbombings
inJakarta in2009,allshowedthatsoft targetsareattractive
to terrorists. The mode of operation in the Bali bombings
comprised multiple attacks with the first bomb occurring
inside a night club, and subsequent car bombs outside to
cause maximum death and injury to fleeing victims. The
JemaahIslamiyaharrestsinSingaporefurtherdrovehomethe
pointofpotentialterroristattacksonthehomefront,withsoft
targetlistsextendingtoincludeselectedtrainstations.Asone
considers these recent terrorist incidents, the listof facilities
toprotectcanspikedramatically,drainingatunprecedented
ratesthealreadylimitedresourcesfordefenceandsecurity.
102 DSTA HORIZONS | 2015
ModernBuilt-upEnvironmentsarePronetoAdverseCollateralDamageFarBeyondtheImmediateVicinityofaBlast
Beyond connectivity enabled via computer networks,
connectivity arising from the need to build and operate
in dense clusters can make it difficult to anticipate where
threatscanemergefrom,andwhichthreatsshouldprotective
design be applied to. Attacks against targets can result in
collateraldamagewithwidespreadimpact.Thebombattack
inSeptember2004ontheAustralianEmbassyinJakartawas
oneagainstarelativelyhardtarget.Itresultedin11fatalitiesin
theimmediatevicinity.Whiletheembassystructureremained
intact, windows in adjacent buildings up to 500m away
shattered,injuringmorepeople.
Thedirectandindirecteffectsofablastdetonatinginatypical
urbanstreetare illustrated inFigure1.Theextentof injuries
due to primary and secondary effects in this hypothetical
scenariowasassessedusingDSTA’s in-houseconsequence
Figure1.Hazardareaunderprimaryandsecondaryblasteffects
103DSTA HORIZONS | 2015
analysistool.Fromthisillustration,itisevidentthatsecondary
effectsofblastlikeglazingdamageordebrishazardsinabuilt-
up environment resulted in human casualties in zones that
extendedfarbeyondtheimmediatevicinityofablast.
TheDiverseSpectrumofOperatingNetworksandConstituentsRequireVaryingTailoredProtection
In the past, systems were less automated with low
interconnectivity to operating networks beyond protected
facilities.Today,relativelysmallincidentscanhavewidespread
impactintermsofconnectivityandfunction.Thefireincidentat
theBukitPanjangExchangeon9october2013resultedinthe
breakdownoftelecommunicationservicesinthenorthernand
westernpartsofSingapore.Thisaffectedtelecommunications
and broadcast services to 270,000 subscribers, including
residential users, a few government agencies, financial
institutions and businesses. A similar shutdown in critical
communicationssystemssuchasairtrafficcontrolcanresult
inpotentiallywiderconsequences.
ImpactOftenExtendsBeyondInitialDesignBoundaries
Key installations have traditionally been given standalone
protection.However, thepeopleoperatingthese installations
liveaspartof thewidercommunity.TheoutbreakofSevere
AcuteRespiratorySyndrome(SARS) in2003hasshownthat
threatssuchaspandemicscandisruptallsectors,rangingfrom
airtraveltohealthservices.Likewise,whendesigningagainst
threats like those from bombs, one has to look beyond the
projectboundariestoensurethattheplacementofprotected
developmentsinanareadoesnot‘passon’threateffectsto
neighbouringareas.
Protective engineering is evolving from a unique auxiliary
capability initially meant only for specialised facilities into a
commonfeature foran infrastructurethat takes intoaccount
the protection of the community that it is a part of. This
demandsnotjustachangeintechnologyoranalyses,butalso
achangeinmindsettolookbeyondone’sowntaskarea.
Toavoidbeingunder-designedinprotectionagainstpotential
threats,radicallydifferentapproachestocriticalinfrastructure
protectionarerequired.
NEW APPROACHES TO CRITICAL INFRASTRUCTURE PROTECTION
Infrastructuresshouldnotonlybeable towithstandattacks,
butalsorecoverafteranattackandresumefunction.Assuch,
itisnecessarytobuildresiliencyintocriticalinfrastructures.
Resiliency is the ability to resume normal operations and
function after an attack. Developing infrastructure resiliency
does not only mean improving the physical protection
of infrastructures to withstand attacks. It also allows the
infrastructuresystemtosustainlimitedextentofdamage,with
recoverysystemsthathavebeenputinplacetoensurereturn
tonormalcywithinashorttime.Abalanceneedstobestruck
between providing full physical hardening and designing to
allowpartialdamagewithswiftsystemrecovery.
Designing a system with resiliency is a prerequisite for the
continued survival of communities after attacks. Systems
designedwithresiliencyhaveparticularattributeswhichenable
communitiestorecoverquicklyfromdisasters.Theseattributes
include the ability to resist, absorb, recover fromand adapt
quickly to disruptions, and to resume system performance.
Somelevelofsystemdamagemaybeacceptable.
Resilientsystemdesignbeginswithanintimateunderstanding
of how a system works as well as how it degrades and
recovers.This,togetherwiththeabilitytodeterminetheexact
levelsofsystemdamagesustained,allowscomponentstobe
enhancedwheretherepairandsystemrecoverycanbedone
withinrequiredtimeframes.
Design for resiliency can be achieved through a right
combination of protective engineering design, system
redundancy,design robustnessandcontingencyplanning to
counterasymmetricalthreatsordisruptions.
In theArt ofWar, ancientmilitary strategistSunTzu,wrote:
“知彼知己,百戰不殆”.Thisistranslatedas“Knowyourenemy
andknowyourself,andahundredbattlescanbefoughtwithout
losing a single one”. In the context of designing protective
infrastructures, knowing your enemy involves understanding
the threat. Knowing yourself involves understanding the
operationalneedsandpotentialweaknesses.
The boundaries of this paradigm can be extended. Apart
from knowing yourself and the enemy, understanding the
interconnectionswithsurroundingelementsisjustasimportant
as it raises awareness of what could potentially go wrong.
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104 DSTA HORIZONS | 2015
Theseformthebackboneofdesigningforresiliencywiththe
preservationofaninfrastructure’scorecapabilityinmind.
WhatEmergesFromtheExtendedParadigm
Protection Concept Development Without Definition of Threat
Itispossibletodesignfacilitiesforprotectionwithoutdefining
a precise threat. This is done by expanding the area of
coveragebeyondtheimmediatefacility,consideringsystems
vulnerabilitiesanddesigningtoincorporatemitigationsystems.
For example, a new annex building next to a cluster of key
buildingsmaybeconstructedandthequestionofhowresilient
or protected should the annex be arises. The base level of
protection and protective detailing can be determined by
examiningtheannexbuildinginrelationtotheexistingcluster,
and the effect of the cluster’s surroundings in introducing
threatstotheannexbuilding.Afterthis,adetailedexamination
of the annex building’s constituents can be carried out and
specificareasfurtherreinforcedifnecessary.
Beyond the design of buildings, the concept of developing
protectionoptionswithoutaprecisethreatcanalsobeapplied
to infrastructurenetworks, includingnetworks forpowerand
fuel.When an engineer designs a power or fuel distribution
network system infrastructure, factors to consider include
thetypeofcriticalfunctionthatthenetworksupportsandthe
environmentthenetworkisoperatingin,asopposedtowaiting
forthedefinitionofthethreat.Aspartofthedesigniterations,
the network design can be scrutinised and vulnerabilities
identified.
Vulnerabilities can include a single-point-of-failure, common
modes failure and areas where even rudimentary forms of
protectiondonotexist.Strategiestoovercomesingle-points-
of-failureinthesystemcanincludetheincorporationofalternate
distributionpathstocriticalnodes,orthephysicalseparation
ofcriticaldistributionnodes.Strategiestoovercomecommon
modefailurescanincludetheuseofindependentbackup.For
fueldistributionnetworks,backupcancomeasalternatefuel
supplyfromfuelbowsers.Inthecontextofpowerdistribution
networks,thiscanbestandalonebackupgenerators.
Customised Protection of Critical System and Equipment
Considering the varying damage tolerance of different
systems,physicalhardeningneedstobecustomisedtomatch
what the buildings contains. In the event that the threat is
biggerordifferentfromwhatwasanticipatedinthehardened
design,orifthecostofhardeningisprohibitive,othermeansto
ensuresystemavailabilityandquickrecoveryareneeded.For
example,thereareseveraloptionstoprotectasatelliteantenna
dishagainstweaponeffects.Tominimisethreatexposure,the
missioncriticalsystemcanbesitedawayfromareasproneto
attacks.Toreducetimeneededforrecovery,mobileantennas
canbeutilised.
Future protected facilities need to move away from mass
produced one-size-fits-all approaches to customised ones
designed not just for the individual facility, but for a larger
networkorcommunitywhichthefacilityisapartof.
Including Time Domain and Usage Pattern Considerations When Designing Critical Infrastructure Protection
Improving resiliency through system design in space alone
may not suffice. operational characteristics such as time
and usage patterns need to be considered. How people
respondplaysanimportantroleinachievingmissionsuccess.
understanding howpeople respond to crises over time and
how usage of infrastructures varies as stages of a crisis
unfoldwill beessential.Buildinghardenedshelters inpublic
undergroundtrainstationsmayprovideprotectiontomasses
of travelling commuters in times of crisis. However, people
in high-rise residential buildingsmay not able to get to the
publicshelterintime.Forthem,individualhouseholdshelters
meet their protection needs better because they can get to
thesheltersquicklyandcancarryonwithotheractivities in
betweenalerts.Thisallowsagreaterlevelofnormalcyevenin
timesoftension,withbenefitsforthepopulationtobeableto
weatherprolongedperiodsof tension incrises.Furthermore,
a shelter servesmultiple uses, including community use for
public shelters and family use for household in peace time.
However,onemustnotoveroptimisedesignsortrytosqueeze
toomanyusagepatternsintoaprotecteddesign.Inthecase
ofhouseholdshelters,iftheshelterisusedonlyasastoreroom
itmightnot fulfil itsoriginal intent toshelter familieswithout
preparationstoemptyoutmassivestores.
105DSTA HORIZONS | 2015
6
6
6
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0 10 20 30 40 50 60 70 80 90 100
1
2
3
4
Extent of Injury
Floo
r Level
Human Injury Profile at 7am
Minor Non-‐Life threatening Life threatening Fatality
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60
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8
8
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2
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4
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Extent of Injury
Floo
r Level
Human Injury Profile at 10am
Minor Non-‐Life threatening Life threatening Fatality
Threat Scenario A large bomb detonates at standoff distance of 10m from the 5-storey office building outline as shown in the diagram. Building Information Height = 30m ; Offset = 25m; Width = 50m ; Span = 50m Total Occupancy = 100pax per floor (total = 400pax in building) Assumed Occupancy = 5%(7am); 100%(10am); 25%(12pm)
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15
2
2
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1
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1
1
0
3
2
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0
0 10 20 30 40 50 60 70 80 90 100
1
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Extent of Injury
Floo
r Level
Human Injury Profile at 12pm
Minor Non-‐Life threatening Life threatening Fatality
Figure2.Expectedhumaninjuryprofileoverdifferenttimesoftheday
Checking Complex Usage Interactions in Time and Space for Emergent Vulnerabilities
The probability of threat occurrence and severity of its
consequences can fluctuate over the time-space domain.
Figure 2 illustrates the expected profile of human injury in
anofficebuildingwhena largebombdetonatesat the front
of thebuildingoverdifferent times in theday.Changing the
operational flowwithin the infrastructure facilitycanmitigate
the effect. For example, the consequences of an explosion
atanoperationalfacilitycanbereducedbyvaryingthetimes
whenpeoplemove throughabuilding such that it doesnot
coincide with times when a large bomb may be around. A
thorough understanding of the operational processes over
time is needed. Table-top exercises should be conducted
to simulate operational processes and study how people
andprocessesreact to the introductionofdisruptiveevents.
Thiswouldalsohelpplannersanddesignersappreciatehow
infrastructuresystemsandpeoplerespondtocrises.Realistic
trainingregimeswillfurtherbuildupconfidenceandknow-how
incrisismanagement.
Beyondthefocusonmodellingweaponseffectsonbuildings,
modelling and simulation can be extended to workflow
analysis,andcanenabledesignoptimisationforsurvivability
and resiliency. For facilities where mass congregation of
people or vehicles is expected during operation, modelling
tosimulatehumanandtrafficflowswillprovidecriticalinputs
toplanners,designersandstakeholderson theadequacyof
infrastructure system formission support. ground exercises
are needed to validate planning and design assumptions.
Fromthisunderstanding,anestimateofhowmuchandwhere
protectionandresiliencycanbestbe injected intoabuilding
systemcanbemade.
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106 DSTA HORIZONS | 2015
OPERATIONALISING THE NEW CRITICAL INFRASTRUCTURE PROTECTION DESIGN FRAMEWORK
Asystematicanditerativeapproachtoidentifycrediblethreats
and address the comparative risks and vulnerabilities is
illustratedinFigure3.
MissionIdentificationandVulnerabilityAssessment
The process of designing critical infrastructures beginswith
knowing the mission and identifying mission critical assets
thatneedtobeprotected.Athreat independentvulnerability
assessment is then conducted to identify single points of
failure, common modes failure, and areas of inadequate
protection.
ConsequenceAssessment
Threatsarethenintroducedandconsequencestofunctionality
and collateral effects are analysed. For a car bomb threat,
parameters of interest include the location of the bomb
in relation to the building. Consequence assessments are
performed using physics-based computational models
Define Mission Statement
Iden0fy Key
Mission Assets
Consequence Assessment
Mi0ga0on Strategy
Implementa0on
Threat-‐Independent Vulnerability Assessment
Review Design Op0ons to improve cost effec0veness of design
Measure of Effec0veness of Design Op0ons
Cost Analysis
Threat/Hazard Assessment
Iden0fy credible threats/hazards through Opera0onal Analysis, modelling and simula0on
Risk-‐based Assessment
Probability of Survivability of System
Impact to opera0on, social, security etc.
Figure3.Vulnerabilityandconsequencesassessmentframework
to derive blast loads on the building. These blast loads are
thenusedtoassesshowthetargetedbuildingrespondsand
the collateral effects on surrounding buildings. DSTA has
conductedalargebodyofresearchworkonexplosioneffects,
structuralresponseandprogressivecollapseincollaboration
withlocalresearchinstitutesandoverseascollaborators.DSTA
hasalsobuiltupcomputationalknow-howtomodelexplosion
effects.Explosivetestsareconductedtoensurethevalidityof
the research outcomes andmodels against realistic threats.
Figure 4 illustrates a collaborative explosive testing effort to
derive blast pressure data for validation against numerical
blastpredictionmodels.
Research outcomes are codified into analysis software
anddesignguides thatcanbeaccessedbyawiderpoolof
engineers.Figure5showsdatafromexplosivetestsconducted
onlocalwindowtypestoensurethatthewindowperformance
isconsistentwithpredictionsfromfastrunningtools.
Mitigation
oncepotentialconsequenceshavebeenassessed,systems
tomitigate vulnerabilities and consequences are developed.
operational analysis tools can be used to quantify the
effectiveness of different design options, thereby facilitating
designoptimisation.
107DSTA HORIZONS | 2015
Application
Physical Modelling
Mathematical Modelling
1
Conceptualization
Numerical Simulation Explosive Testing Preliminary Calculations
Model Validation
Acceptable Agreement
Blast Effect Prediction for Consequence Assessment Reality of Interest
Figure4.ValidationofnumericalmodelsthroughcollaborationwithuSCombatingTerrorismTechnicalSupportofficeonurbancanyonexplosivetests
Figure5.Comparisonbetweenwindowresponseexplosivetestresultswithin-houseengineeringtoolsforexplosionconsequenceassessment
observeddamageinthelowhazardrange
PredictionofBlastLoads WindowResponseModule
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108 DSTA HORIZONS | 2015
OptimisingResourcestoYieldCost-EffectiveSolutions
To ensure resource optimisation, cost-benefit analysis is
carried out on various implementable design options. The
relevant stakeholders must strike a balance between the
financial commitment to improve system resiliency and the
acceptanceofresidualriskassociatedwithtimeforattacks.
ClosingTechnologyGaps
DSTA is involved in researchwork toclose technologygaps
in critical infrastructure resiliency. These have evolved from
thetraditionalfocusonhardeninginfrastructurestoresistand
absorb extreme loads, to programmes that facilitate system
resiliencyandrecovery.onesuchresearchprogrammederives
data on the survivability of buried utility networks against
weaponsattack.Thedataisincorporatedintoanoperational
analysistoolthatdeterminestheoverallsystemutilitynetwork
survivabilityusingfaulttreeanalysis.
CONCLUSION
This paper illustrated how achieving a balance between
protectionandresiliencycanimprovetheoverallsurvivability
of critical infrastructures. A critical infrastructure design
framework was also discussed, which involves more effort
spentassessingone’sownvulnerabilitiesandinterconnections
than before. It is also coupled with greater efforts to look
beyondtraditionalprojectboundariesconstantly.
However,protectionofcritical infrastructuresystemscan lag
behind technological advancements and resourcefulness of
adversaries. Therefore, the design of critical infrastructures
needs dogged perseverance and an attention to detail.
Implemented protection concepts should be reviewed
periodically,orruntheriskofobsolescence.Moreoftenthan
not, lapses in protection of a critical infrastructure system
surface only after attack events. The review of protective
conceptsneedstobecarriedoutcollectivelybybothtechnical
and operational communities. Thereafter, the potential for
future upgrades should be incorporated into the protective
designwherepossible.
REFERENCES
AttackbyStratagem.(n.d.).InChineseTextProject.Retrieved
fromhttp://ctext.org/art-of-war/attack-by-stratagem
Corley,g., Hamburger, R., &McAllister, T. (2002). Executive
summary. In T.McAllister (Ed.),World TradeCenter building
performancestudy:datacollection,preliminaryobservations,and
recommendations (pp.1-7).Retrievedfromhttp://www.fema.
gov/media-library-data/20130726-1512-20490-7075/403_
execsum.pdf
Infocomm Development Authority of Singapore. (2014,
May).Fire IncidentatBukitPanjangExchangeon9October
2013. Retrieved from https://www.ida.gov.sg/~/media/Files/
About%20us/Newsroom/Media%20Releases/2014/0506_
CompletesInvestigation/Factsheet_FireIncidentBukitPanjang.
NationalConsortiumfortheStudyofTerrorismandResponses
to Terrorism. (2004). Incident Summary. InGlobal Terrorism
Database. Retrieved from http://www.start.umd.edu/gtd/
search/IncidentSummary.aspx?gtdid=200409090001
109DSTA HORIZONS | 2015
BIOGRAPHY
ONG Kwee Siang Steve is a Manager
(Building and Infrastructure) involved
in the design development and project
managementof building infrastructures for
theMinistryofDefenceand theSingapore
ArmedForces.Heisalsopartofthemulti-
disciplinary DSTA team that carries out
vulnerability assessments and mitigation
studies. Steve graduated with a Bachelor of Engineering (Civil
Engineering) degree with First Class Honours from Nanyang
Technologicaluniversityin2006.HefurtherobtainedaMasterof
Science(ProjectManagement)degreefromtheNationaluniversity
ofSingapore(NuS)in2013.
CHONGOiYinKarenisHeadEngineering
(Building and Infrastructure)who is driving
R&Defforts inProtectiveEngineering.She
has extensive experience in explosive
testing, protective systems design and
blast modelling and analysis. She won
the Defence Technology Prize Team
(Engineering) Award in 1999, 2006, 2007
and2011.KarengraduatedwithaBachelorofScience (Nuclear
Engineering) degreewith FirstClassHonours fromQueenMary
College,universityofLondon,uK,in1986.Shefurtherobtained
aDoctorofPhilosophy(NuclearEngineering)degreefromQueen
MaryandWestfieldCollege,universityofLondon,uK,in1991.
SEE Thong Hwee is Head Capability
Development (Building and Infrastructure)
who oversees building infrastructure
development of joint facilities. He also
providesprotectiveengineeringconsultancy
for critical infrastructures. Thong Hwee
hasplayeda key role in extendingDSTA’s
protective technology capabilities to
Singapore’s homeland security. He was involved in numerous
projects that improved thephysical resiliencyof critical national
infrastructures, such as the national power grid, mass rapid
transportnetwork,variousgovernmentfacilitiesandseveraliconic
buildingdevelopments.ThongHweegraduatedwithaBachelor
ofEngineering(CivilEngineering)degreewithHonoursfromNuS
in 1997. He further obtained a Master of Science (Engineering
Mechanics) with Specialisation in Explosives Engineering, from
theNewMexicoInstituteofMiningandTechnology,uSA,in2002.
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110 DSTA HORIZONS | 2015
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