UNSD - Mapping and Sensus Workshop: Lusaka, Zam bia 8 -12 October 2007 Slide 1 Mobile GIS UNSD Workshop Pieter van Jaarsveld An Overview to a professional GPS/Mapping collection solution Mobile GIS Specialist
Mar 31, 2015
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 1
Mobile GISUNSD Workshop
Pieter van Jaarsveld
An Overview to a professional GPS/Mapping collection solution
Mobile GIS Specialist
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 2
Survey
Recreational GPS users?In-car navigation users?Capturing GPS data in the field for GIS use?Plan to in the next year?
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 3
Global Positioning System
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 4
Global Positioning System
• Where on earth am I ?
Constellation of satellites
Handheld devicesVarious ApplicationsAccuracy
What is GPS?
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 5
1
Correct for Atmosphere & Ionosphere
Differential Corrections
43
Trilateration using speed of light
Accurate clocks are required2
Use ephemeris for satellites’ location
5
GPS in 5 Basic Steps
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 6
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 7
Control SegmentProvides worldwide coverage and control
• 365/24/7
Master Control station• Colorado
Four support stations• Hawaii• Kwajalein• Diego Garcia• Ascension Island
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 8
Space SegmentGPS satellite constellation
• 24 satellites• Replenishment occurring
Satellite design • Lifetime 7.3 years• 16 satellites over 9 years old
28 Satellites in GPS Constellation
0
2
4
6
8
10
12
Under 3 3-4 5-6 7-8 9-10 11-12 13+
Age (Years)
Nu
mb
er
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 9
User SegmentEquipment produced by Military and Private
companies
Receives signal and computes• Position• Time• Velocity
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 10
How do we position ourselves?
Simple Geometry• Velocity times vs travel time
Determine Radio Wave Time Travel • Accurate timing
Measure Distances• Known orbit locations
Trilateration• Distances not angles
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 11
Sources of Positioning ErrorIonosphere and Atmospheric delays
Satelite and receiver Clock Error
Multipathing
Dilution of Precision
Receiver Issues
Selective Availability
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 12
• Two receivers track the SAME signals and errors at the SAME time
• Derived corrections are then applied to the data during postprocessing
– GPS Analyst contains tools for DC• Does not correct multipath
Base
Data Collector
Differential GPS
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 13
Red = Uncorrected GPS
Green = GPS after differential correction
Differential Correction
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 14
Selecting a GPS
Recreational versus Professional GPSAccuracy
• Tens of meters versus sub meter
GIS data integration• Format conversion
Attribute collection• Customised forms, business rules
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 15
Data Collection Software
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 16
Data Collection Workflow (server to server)
ServerServer DesktopDesktop MobileMobile DesktopDesktop ServerServer
Enterprise Geodatabase
Export to PGDB
Check out
Copy to device
ArcPad
Copy to Desktop
Check In
Post process
Import to Enterprise
Data validation
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 17
Check out and post processing is performed on a personal geodatabase NOT directly from enterprise. WHY?•GPS detail not required in enterprise•Topology not supported in GPS Analyst
Carefully choose extents. WHY?•Large extent limits the amount of data capture
Current only personal geodatabase support, efforts to supporting file geodatabase underway.
UC 2007 Tech SessionsUC 2007 Tech Sessions 1717
Data - things to remember
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 18
What is ArcPad?•Part of ESRI overall mobile strategy•A mobile GIS application for field mapping applications
•Designed for broad range of mobile systems•Allows input from GPS receivers, rangefinders, digital cameras and other devices
•Provides a generic set of mobile GIS functionality •Extensive customization capabilities•Extends Geodatabase to the field through disconnected editing
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 19
What can you do with ArcPad? • Use your existing data • Add data from the Internet• Move around your map• Query your data• Edit your data• Measure distance, area, and bearings on your map• Navigate with your GPS• Customize ArcPad to streamline your workflow
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 20
ArcPad BenefitsStreamlines the workflow
• Smart, task oriented solutions
Increases productivity• Reduces office work and data entry time • Improves the accuracy of data• Resulting in more accurate and current data for
analysis and decision making
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 21
ArcPad FunctionalitiesImproved performanceEnhanced editing tools
• Snapping• Undo• offsets for points, lines, polygons• repeated features• segmented line features
Camera and rangefinder supportImproved symbology and labelingSupport for Graphics layer
• for redlining or mark-upImport/export tools for ArcGISCustomization
• wizard for creating custom forms
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 22
ArcPad FunctionalitiesSignificant performance gains on startup time
• Pre-buffering input• Affects Applets, Layers, Scripts etc. (i.e ALL XML and
Scripts)• Delayed loading of projection data
Usability enhancement• Datum conversion wizard• Picture browsing capabilities on Windows Mobile 5 devices• Additional language packs available
Quality improvements• About 80 bugs have been identified and fixed!
Minor feature improvements• Object model improvements (Picture chooser, File object ,
Inter-process methods)
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 23
Configuring the GPS
Protocol = “Trimble GPSCorrect” or “NMEA0183”Port = “COM3: TSIP Serial Port (GeoExplorer)Port = “COM7: TSIP Serial Port (JunoST)Port = “COM2: TSIP Serial Port (Recon XC)
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 24
Streaming and AveragingAveragingnumber of incoming GPS position
coordinates that ArcPad uses for calculating an average coordinate
StreamingPosition Interval = How frequently
ArcPad uses incoming GPS coordinates
Distance Interval = ArcPad uses incoming GPS coordinates only when greater than this distance from LAST coordinate used
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 25
GPS PreferencesQualityMinimum and maximum values can be
predefinedCan be made compulsory to ensure
data integrity
Warning and AlertsVisual and Audio alertsConstantly warns the user if not
complying to presetsWill inform the user of GPS statusCan be annoyingCan be switched off
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 26
Editing using the GPSFirstly, make layer
editable (one point, line, polygon, at a time)
Then select feature type
Then select GPS capture tool
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 27
UC 2007 Tech SessionsUC 2007 Tech Sessions 2727
DOPDOPSV GeometrySV GeometryHigh = BADHigh = BAD
Low = GOODLow = GOOD
SNRSignal to
Noise Ratio
High = AccurateLow = Productive
Elevation MaskElevation MaskDefault 15Default 15
No. of SatellitesMin of 4 SV’s
Ensuring data quality
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 28
ArcPad with other devicesArcPad can be used with:
• Digital Cameras• WiFi enabled cameras• BT enabled camerasUse “Camera” tool• Photo Layer• Custom Form
• Laser Rangefinders• What is your accuracy needs?
• External GPS
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 29
Where are the Satellites? • Your Body is an obstruction!
Point Data Collection • Position First and Attributes Second
Polyline & Polygon Collection • Streaming (less accurate but dynamic)• Vertex Averaging (more accurate and static)
UC 2007 Tech SessionsUC 2007 Tech Sessions 2929
Data Collection Techniques
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 30
•Do you understand Sticky Keys?•Have you used appropriate colours and line thicknesses?
•Is your device locked?•Don’t you pick on me! (Avoid clicking on the map)•The art of using a stylus•Slow down and smell the flowers!
UC 2007 Tech SessionsUC 2007 Tech Sessions 3030
ArcPad Tips and Tricks
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 31
Mobile GIS
ArcPad Orientation Demonstration
Mobile GIS
UNSD - Mapping and Sensus Workshop: Lusaka, Zambia 8 -12 October 2007
Slide 32
Thank you
Mobile GIS [email protected]
(011) 238 6300