ECDIS

3 Bach NW Samenvatting ECDISp. 1/24

IntroductionIntroduction

What is ECDIS

ECDIS = Electronic Chart Data Display Information System Requirements specified in SOLAS Electronic chart = map or geographically related information displayed on screen

Production of electronic charts

Two wayso Rastero Vector

Raster charts

Electronic facsimile of existing paper chart Like a scan Electronic image = exactly same as paper chart Size of chart limited to size of screen Only small part of chart visible Zooming in => lines become small squares

Vector charts

Technology more sophisticated List with information to draw chart = stored, not image itself Includes all positional information in latitude and longitude All objects described by vector data Detailed information View of chart changeable Chart projection changeable Automatic detection of approach toward potentially hazardous situation Performance standards defined for system using vector charts Vector data to be used defined by IHO Use of Electronic Navigational Chart Based on standard S-57 Unofficial vector system = Electronic Chart System ECDIS in place of paper chart only if adequate back-up arrangements are present Regions without ENC => Raster Navigational Chart


Electronic chart system

Essential componentso Datao Hardwareo Softwareo Interface facilitieso Electronic interconnections

Electronic chart dataElectronic chart data

Electronic navigational chart data

Is basic data for ECDIS Compiled to strict rules

Format of ENC data

Object classo Unique name (= acronym)o Numeric code

List of feature object attributeso Acronymo Numeric codeo Divided into 3 groups

A: individual characteristic B: information for use of data as needed for displaying C: administrative information

Positional information not an attribute Linear boundaries shown as succession of small lines Loading can take long

System ENC

Database in internal ECDIS format Transformation of entire ENC Accessed by ECDIS for display & other navigational functions Equivalent of up to date paper chart May contain information added by mariner & other sources

Raster navigational chart

Facsimile of paper chart Can be single chart or collection of charts


Private data

Available from number of companies Most vector data Not official

IMO requirements concerning ECDISIMO requirements concerning ECDIS

SOLAS

Chapter V Recognizes if used with official data & appropriate back-up

SOLAS Chapter V regulation 2

Definition nautical chart/nautical publicationo Book, map or databaseo Issued officially by Government or Hydrographic Officeo Meet requirements of marine navigation

SOLAS Chapter V regulation 19 paragraph 2.1.4

All ships Charts & publications to plan & display route & plot & monitor positions on board

SOLAS Chapter V regulation 18 part of paragraph 4

ECDIS must be conform to relevant performance standards Definition ENC

o Database standardized to content, structure & formato For use with ECDISo Conform to IHO standardso Issued by authorized institutiono Contains all chart information necessary for safe navigation

Paragraph 1.9o ECDIS may operate in raster chart display system mode

Paragraph 1.2 appendix 7o When in RCDS mode => appropriate portfolio up to date paper charts on board

Paragraph 3.7 appendix 7o Appropriate portfolio up to date paper charts = paper charts of sufficient scaleo Provide adequate look-ahead capabilityo Coastal states provide details of charts meeting requirements


SOLAS Chapter V regulation 19 paragraph 2.1.5

All ships Back-up arrangements meet functional requirements of subparagraph .4 if fulfilled by

electronic means

SOLAS Chapter V regulation 19 paragraph 2.10

Ships engaged on international voyages fitted with ECDISo

o Exemption if ship permanently taken out within 2 years of specified implementation date

IMO equipment requirements

Permanent label if equipment meets requirements Wheel Mark in Europe

o For all EU approved bridge instruments

o


IMO back-up requirements

Capable of prompt access to charting facilities Latest edition of information Following functions in route monitoring mode

o Plotting ship’s positiono Taking courses, distances & bearingso Displaying planned routeo Displaying time labelso Plotting adequate number of points, bearing lines, range markers …

Separate power supply Possible solutions

o Paper chart folioo Second ECDISo Integrated navigation systemo Chart radaro Solution approved by flag state

IMO chart data requirements

Data must be up to date Chart information of latest edition S-57 format!!!!

IMO training requirements

Users properly trained Requirements of Model Course Appropriate familiarization training on actual equipments on board


Operational principles of ECDISOperational principles of ECDIS

ECDIS configuration

Critical aspects

o Interconnected with back-up position fix systemo ECDIS back-up systemo Primary ECDIS connected to emergency power supply

Input of sensor informationo ENC always based on WGS84, private data could be differento Speed input over water / groundo Bearings magnetic / trueo Target information relative / true

ECDIS not used as collision avoiding system

Data loading

Permits

Data of majority of charts = encrypted Permits needed to read information Permits need to be loaded

o ECDIS newly installedo More charts neededo Loading charts from unused sourceo Permit expiredo Data supplier sends new permit

Contains equipment identification data (= user permit)o Must be on board

Covers specific charts or areas over specific time period Warning when about to expire

Base data

Chart data base loaded after installing permit Can take some time


Chart updates

Apply latest updates Most recent disk inserted Updates all charts & new editions ECDIS displays record all ENC updates including

o Identification number of updateso Date & time of application / rejectiono Anomalies encounteredo Type of application

Raster charts state of updating permanently availableo Chart number & origino Edition dateo Reference to last Notice to Marinerso Date of publication of update CD

Possible to update while in route monitoring mode Updates should be applied in port

Remote updating

Could be directly communicated to ship Updates should be permitted by user Better no direct link because of viruses

Manual updates

Object will not disappear but deletion shown by orange lines Numerous of reasons for manual update

Viewing charts on ECDIS

Modeso Route planningo Route monitoring

Single operator action to route monitoring display with ship’s position Position shown on largest scale available in centre of screen Possibility to enter coordinates any position & display on demand

Basic display settings

Main viewing modeso Daytimeo Dusko Night-time

Daytime colours similar to paper chart colours


Projection

Normally fixed 2D Some 2D & 3D

Symbolism

Two formats One based on traditional symbols Other simplified Defined within IHO

The ? symbol

Magenta Any object not sufficiently described / no existing symbol

Display detail

Main options for setting detailo Display base

Coastline Ship’s safety contour Isolated underwater dangers Scale, range & north arrow Units of depth & height Display mode

o Standard display Display base Drying line Buoys, beacons, aids to navigation & fixed structures Boundaries of fairways, channels … Visual & radar conspicuous features Prohibited & restricted areas Chart scale boundaries Indication cautionary notes Ships’ routeing systems & ferry routes Archipelagic sea lanes

o All other information Submarine cables & pipelines Details isolated dangers Details aids to navigation Contents cautionary notes ENC edition date Most recent chart update number Magnetic variation Graticule Place names

To standard display by single operator action


Scrolling and zooming

Smallest allowable chart display: 270 mm x 270 mm Not including non-chart data ENC

o Bar visible to focus on zoom level RNC

o Only displayed at compilation sizeo Equal to real imageo Sometimes as overview showing whole chart zoomed out

Displaying detailed information

Much available information not displayed Easily accessible by clicking object of interest

Displaying orientation mode

North up mode is required Other modes also allowed

Displaying motion modes

Route monitoring mode True motion / relative motion

Own ship settings

Own ship dimensions

Physical parameters Chart of sufficient scale => vessel shown in scale Position fix reference point defined Position radar antenna defined

Depth indication

To identify safe & unsafe water depth Depth data normally referred to LAT Safety contour

o User-entered depth giving adequate safety allowanceo Bold black line

Safety deptho User-supplied deptho Affects appearance of spot soundings

Deep & shallow area indicationo By use of colour


Safety domain

Automatic check for approaching hazards to navigation Route monitoring mode always turned on Route planning mode can be turned on to check Minimum requirement

o Alarm when ship will cross safety contouro Alarm / indication when ship will cross boundary of prohibited area or area

with special conditionso Alarm when limit for deviation from planned route is exceededo Indication when ship will closer to danger shallower than preset safety contour

All alerts generated from relevant chart at largest scale available Safety domain by following parameters

o Depth (safety contour & depth)o Forward extent (look-ahead time / range)o Lateral closeness (specified distance)

Units and legend

Legend general information is displayed Minimum

o Units for deptho Units for heighto Scale of displayo Data quality indicatoro Vertical & horizontal datumo Value safety depth & contouro Magnetic variationo Date & number last updateo Edition number & date of issue of ENCo Chart projection

ECDIS tools

Mandatory navigational toolso Indicating fixed geographical position on display by input of coordinateso Presenting coordinates of selected pointo Method to calculate range & bearing between positionso Method to calculate position given range & bearing from known positiono Methods to incorporate relevant geodetic calculationso Electronic bearing lines with resolution of 0,1°o Variable range markers with resolution compatible with range scale in useo Capability to enter & plot manual bearing & distance LOPs

Reference to user manual for exact procedures


Navigational elements and parameters

ECDIS required to display navigational elements & parameterso Past track with time markers for primary & secondary tracko Vector for course & speed made goodo Variable range marker & electronic bearing lineo Cursoro Dead reckoning position & timeo Estimated position & timeo Fix & timeo LOP & timeo Transferred LOP & time (predicted & measured tidal stream / current vector)o Danger highlighto Clearing lineo Planned course & speed to make goodo Waypointo Distance to runo Planned position with date & timeo Rising & dipping range of lightso Position & time of wheel over

ECDIS marine information overlays

Additional types of non chart data useful for safe navigation Removable by single operator action Can be

o Tracked radar targets & radar imageso AIS targetso Predicted current vectorso Safety informationo Meteorological data

Not yet international standards for overlays

Data quality

Data might be inaccurate Reasons

o Physical changes since latest surveyo Changes to position of navigational aids (intentional / accidental)o Survey may be inaccurateo Original survey based on sparse number of spot soundingso Chart may contain compilation erroro Chart not suitable for purpose in hand

Zone of confidence

Indicates that ENC data meets minimum criteria for position & depth accuracy


Can be seen as survey accuracy

Use of ECDIS for route planningUse of ECDIS for route planning

Preliminary tasks

Basic information must be known to officer Includes

o Conditions & state of vessel, stability & equipmento Dimensions, draught & manoeuvring characteristic datao ENC data at appropriate scaleo Latest updateso If RNC => updated paper chartso Notices to Marinerso Up to date sailing directions & pilot bookso Up to date port informationo Details shore-based emergency response arrangementso List of lights and fog signalso List of radio signalso Tide tables for relevant areaso Tidal stream atlases and/or tidal stream MIOs for ECDISo Latest maritime safety information (NAVTEX)o Ships’ routeing guideso Waypoint listso Weather & climate data including weather routeing planso Radio signal informationo Information relating to pilotageo Load line requirements

Notices to Mariners

Efficient for providing correct information on paper charts Much of information only for use on paper charts Not true for all included information Vessels navigating solely on ECDIS still able to access Notices

Temporary & preliminary notes

Important items within Notices Information only valid for limited period Preliminary notices early notification of intended changes Many objects in ENC data time varying attribute Usable as part of ENC update to give timely information NAVTEX messages geographically displayed shows latest information Doesn’t cover all T&P information


Preparing the first cut route

New route based on existing routes Starting from scratch

o Basic route plan between arrival & departureo Rhumb line / great circleo If great circle: break circle into number of rhumb lineso Consider safety & environmento Insert waypointso Work on ever increasing scale

Basic toolso Adding waypointo Deleting waypointo Changing position of waypointo Reversing waypoint order

Possibility to enter waypoints manually by coordinates Entry of waypoint lists on removable media Waypoints also visible as table

o Input information from keyboard

Mariners notes and critical points

Proper detailing of route Check that route has taken intro account all safety information When underway & NAVTEX message => changes to plan Insert maritime safety information into correct position Allows placing of

o Text noteso Any symbolo Simple lines or areas with or without colour

Presence of text note by “!” or “I” Some ECDIS connected to NAVTEX Mariners notes include place of VTS calls, planned speed changes & warnings Critical points when specific action is required Alarm generated within specific time before critical point


Detailing and checking the route

In largest scale alignment with visual / radar charted features Automatic checking facility based on

o Safety contour & deptho Safety heighto Safe passing distance

Route closer to following geographic areaso Traffic separation zoneo Inshore traffic zoneo Restricted areao Caution areao Offshore production areao Areas to be avoided (existing & user-defined)o Military practice areao Seaplane landing areao Submarine transit areao Anchorage areao Marine farm / aquacultureo Particularly sensitive sea area

Time varying objects

Can be included in ECDIS Specific requirements

o Obtain information about date of implementation & contents of updateo Update displayed during time of validityo Used by internal checking facilities

Tabulated route plan

More detail added by showing in tabular form Typical entries

o Waypoint numbero Waypoint nameo Waypoint coordinateso Leg course & lengtho Speedo Turn informationo Date & time for ETA @ waypoint

Pilotage information

Inputting pilotage information Include

o Clearing lineso Parallel index lines


o Mariners’ Notes

Final checks and procedures

Automatic safety checking facility Bridge instructions followed Approved route saved and copied to back-up system

Use of ECDIS for route monitoringUse of ECDIS for route monitoring Major aid for route monitoring

Basic route monitoring features on ECDIS

Own ship scaled on large scale display Own position not precise Course & speed vector Single arrowhead if water stabilisation Double arrowhead if ground stabilisation

Executing the route plan

Select planned route Also alternative routes Progress along route automatically monitored

Checking integrity of the navigation solution

Navigational information never assumed correct unless verified Alerts if problem with connected navigational equipment Many problems not automatically detected Comparing displayed position with all other navigational information Plotting manual fixes on ECDIS Coastal passages good visibility => visual bearings Restricted visibility => RADAR

Lines of position

Plotting on ECDIS possible Don’t forget compass errors

Estimated position

If automatic positioning fails Rely on estimated position between each manual fix


Position offsets

Facility for fixed offset of position Not recommended!

Parallel index lines

Often available

Maintaining situational awareness

Charted hazards and alerts

Display should show appropriate detail Alert given when charted hazards enter safety domain

o Alarm if ship crosses safety contouro Alarm / indication if ship crosses boundary area of special areao Alarm if too much deviation from planned routeo Indication when distance from danger shallower than safety contouro Alarm in advance of critical point

Alerts generated not of concerno Planned turn before hazardo Safety contour crossed but route plan includes sufficient tidal heighto Crossing safety contour towards deeper watero Passing closer intentionallyo Entering non hazardous special purpose area

Display of radar and AIS targets

Enhances situational awareness ECDIS is no collision avoidance system!!!

Radar target overlays

Watch out for non matching vector types Useful when radar without chart overlay facilities See geographical area of targets Track ground fixed targets Isolated targets out of position =>

o Targets wrongly identifiedo Targets moved out of positiono Charted errorso Observed target = false echo

Fixed position offset all targetso Position-fix equipment vessel faultyo Position-fix equipment hydrographic organisation faultyo Position-fix system spoofedo Due to fault combined radar / ECDIS system


Radar image overlay

Distracting Establish whether coastlines appear at expected position (integrity check)

AIS target overlay

Many radars not able to display AIS ECDIS as main AIS target display

Track keeping autopilot

Track information Control for autopilot Cautions

o Ship close to desired track & no possible conflicts with other vesselso Position-fix system automatically monitored (alarm if discrepancy too big)o Wheel-over indication given => switch to manualo Alarm at wheel-overo Alarms for cross-track error, course difference & low speed generated

automatically

Voyage recording

Inbuilt voyage recording facility Preserving detailed record for previous 12 hours at one minute intervals

o Timeo Positiono Headingo Speed

Record of track of entire voyage at four hourly intervals Possible to review recorded data Impossible to manipulate information

ECDIS failure

Can fail / give misleading information Relies on other navigation sensors

Transfer to back-up

Ensure safety not compromised due to ECDIS failure Timely transfer possible during critical situations


Back-up using dual ECDIS

Routes & tracks stored in second ECDIS & kept up to date Both units switched on in normal circumstances

Back-up using other electronic systems

Approved ECS or chart radar Flag state gives Certificate of Compliance Must be able to accept routes from planning process

Back-up using paper charts

Appropriate paper chart readily available on chart table Corrected charts Current position plotted at suitable intervals Planned routes pre-plotted

Emergency charts

Back-up system = electronic => carrying set of small scale charts as emergency back-up

Allows vessel to proceed to area of safety

System maintenance

Doesn’t need planned maintenance schedule for hardware Failures rectified by authorized service engineer Software subject to revisions Requirements embedded in standards

o Software maintenance arrangements provided by manufacturerso Current software version displayable on demando Means available to update software

Timely access too List current IHO standardso Status of compliance of extant software versionso Regulatory approval status of software in use


AIS basicsAIS basics

System concepts

Automatic Identification System = digital communication system that allows other ships & stations to exchange positional & other information automatically

Enhance safe navigation Provides information for use by authorities for safety & security purposes VHF IMO states that IAS intended to enhance

o Safety of life at seao Safety & efficiency of navigationo Protection marine environment

Purposeo Help identify vesselso Assist target trackingo Simplify information exchangeo Additional information

Stations include ships, shore stations, non SOLAS crafts, SAR aircraft & aids to navigation

Transmit up to date data includingo Non changing data as name & lengtho Dynamic data as position, course & speed over groundo Voyage related data as destination, ETA & draught

Transmitted data received by all stations within range of transmitting station Displayable in numerous ways Transmission

o Burst of data in time-ordered sequenceo Avoids transmitting at same timeo Two VHF channels usedo Consecutive transmissions alternateo Mostly used

87B (161,975 MHz) 88B (162,025 MHz)


Self-organising time division multiple access

Each station uses defined time slots Time slots aligned to UTC (GNSS used for precise UTC) One minute divided into 2 250 equal slots Individual ships at sea transmit once every 6 seconds System allows distribution data between large number of stations using limited portion

frequency spectrum Determination transmission slots

o Initially listening to existing traffico Establish free slotso Algorithms to choose suitable slots

Degrades when increasing number of stations (range of contact decreases)

Modes of operation

Self organising mode = Autonomous and Continuous Two other modes AIS equipment switches automatically Assigned mode

o Assign individual ship stations intervals & slotso Useful in circumstances causing overload (e.g. SAR operation near busy port)o Revert to A&C after random interval between 4 & 8 minuteso Re-switching is possible

Polledo Requesting specific data directly from ship stations

Regional operating settings

In range of shore station, broadcast parameters remotely controlled Parameters

o Coordinates where settings are to be usedo VHF channels to be usedo Transmit powero Transitional area

AIS can store at least 8 regions Also manual input by users possible


Ship borne equipment

Two AIS receivers One DSC receiver One VHF transmitter Digital processor

o Controls everythingo Collects signals from inbuilt GNSSo Monitors interface with operator & other equipmento Controls inbuilt integrity tests

Propagation of AIS channels

Basically VHF operating on marine-band frequencies Behaves similarly to VHF radios Transmission power

o Differso 2 watt & 12,5 watto Range reduction of 25%

Range around 30 miles if not overloaded Not affected by weather conditions Affected by shielding by land & buildings

AIS data

Communication by standard message types Internationally agreed types by International Telecommunications Union AIS equipment turns relevant received data to understandable information Conversion to correct message type = automatic Relevant groups

o Static datao Dynamic datao Voyage related datao Safety & security related messageso Other user-relevant AIS messages


Static data

Entered only once Remains generally constant Consists of

o Maritime Mobile Services Identity numbero Ship’s nameo Call signo IMO numbero Type of vesselo Length & beamo Location of position fixing antennao Height over keel

Broadcast every 6 minutes Location antenna important in close quarter situations

Dynamic data

Automatically supplied by navigation system Consists of

o Positiono Time in UTCo Course over groundo Speed over groundo Headingo Rate of turn

Manual input concerning navigational status Transmitted at regular time intervals depending on dynamics of vessel

o


Voyage related data

Manually entered & kept up to date Consists of

o Draughto Destinationo ETAo Type of shipo Hazardous cargo typeo Number of people on board

Broadcast every 6 minutes

Safety and security messages

To individual station / all stations Max 160 characters Automatic response if to individual station

Binary messages

Flexible message facility All messages available on digital interface Two categories

o Internationalo National

AIS class B

Non-mandatory fittings Less expensive Detects unused transmission slots Lower power level Number of issues

o Update rate at twice / minute Less effective situational awareness Automatic fusion with radar inappropriate Manual association more difficult

o Increased amount of garblingo Some areas too many Class B targetso Poor education & training of users


AIS limitations

Other ships might not be fitted with AIS Other ships might switch off AIS Not complete picture of situation around ship Transmission of erroneous information Poor sensors Doubtable quality

Use of AIS information in collision avoidance

Less radar assisted collisions Access to dynamic information Surpasses radar in 3 aspects

o Positional accuracy better than 10 mo Less delay for position & course over ground changeso Supplementary information

Passing distance determined with higher accuracy & reliability Manoeuvring restrictions immediately evident More complete information than radar Even better in conjunction with radar

ECDIS

Documents

ecdis o o exemption

database o

europe o

ecdis ecdis

o appropriate portfolio

structure format o

iho standards o

planned route o