1. GPS-iPaq Workshop by Verplanke / de Bie ITC Version Feb ‘03 Mobile GIS techniques with 10m accuracy !!

2. GPS-iPaq Hardware Parts

3. Pocket PC The Compaq-iPAQ pocket PC (64 MB Ram), running at > 200 Mhz under MS-Windows- CE) is able to run ArcPad and to connect to a GPS. The Pocket PC has backlight-features so that in bright sun the screen is still perfectly readable. Arc-Pad Arc-Pad is able to convert GPS readings ‘on-the-fly’ to the required coordinate system. Any image, GT-Sheet, or shapefile can be displayed in Arc-Pad ‘as is’. The GPS position is shown on the loaded maps or images. The user can save the GPS-Tracklog (as lat-long points), or use the GPS to capture shapefiles (point, line, or polygon) in the required projection system. The software allows use of forms (questionnaires), and to draw points, lines, or polygons directly by hand on the screen. Raster images must be converted to SID files using Erdas (v.8.5). Arc-Pad software comes with an extension that loads into Arc-View or Arc-Map. Some relevant info …

4. Example-1 … Pakistan 1881m 2 1038m 2 RMS boundary Digitized line of GT-Road and Circular-Road Peshawar City Points of Interest ForestGIS Office 2 Fields: Part of GT-Sheet ArcPad Menu Scale: 1:65540 DHV guesthouse Digitized “on the road” Scanned topsheet

5. Jan. 2000 Sep. 2002 Example-2 … India IRS-Image (23m Multi- spectral fused with 6m Pan) Digitized “in the field”

6. Example-3 … Iran Jul. 2001 Aster-Image (15m Multi-spectral) Digitized “in the field” and “on the road” Aster-Image, Topsheet, GPS data… All fit !!!

7. Connecting Hardware-1 USB hub Power

8. Connecting Hardware-2 GPS physical connection A GPS serial connector wire needs to be linked to a serial connector wire attached to the iPaq. Both ends are female and need to be connected through a null-modem connector in which pins 2 and 3 are reversed (home made…).

9. Connecting Hardware-2 GPS physical connection A GPS serial connector wire needs to be linked to a serial connector wire attached to the iPaq. Both ends are female and need to be connected through a null-modem connector in which pins 2 and 3 are reversed (home made…).

10. Connecting Hardware-2 Connection precaution While cycling, walking or running, the connections must remain firmly in place. Use tape to provide the required solid ‘fix’.

11. Connecting Hardware-2 Power Watch your battery life On the road, a cigarette-lighter wire provides recharge options for the iPaq. Use rechargeable A4 batteries for the GPS. Carry spares with you at all times.

12. USB hub Activesync  use your CD  will establish the required ‘communication’ Software installation-1

13. Software installation-2 Arcpad on your PC run:

14. Software installation-3 USB hub Arcpad from your PC to your iPaq  install from [Start] - [ArcPad]

15. Hardware settings: GPS GPS settings units’ settings: position format: hddd.ddddd o, map datum: WGS 84, and units: metric ‘interface’ settings: i/o format: NMEA out, and baud rate: 4800.

16. Hardware settings: ArcPad Arc-Pad settings GPS: NMEA protocal, WGS84 Datum GPS Port: port com1, Baud 4800, Parity none, Data bits 8, Stop bits 1, Break 0.

17. To convert ‘on-the-fly’ coordinates send by the GPS to Arc-Pad, at least one Arc-View shapefile must be loaded as Arc-Pad layer for which a projection file (*.prj) exists in the same directory as from where the shapefile was loaded. Example “Enschede” : PROJCS["ED_1950_UTM_Zone_32N",GEOG CS["GCS_European_1950",DATUM["D_Euro pean_1950",SPHEROID["International_1924", 6378388,297]],PRIMEM["Greenwich",0],UNIT[ "Degree",0.0174532925199433]],PROJECTI ON["Transverse_Mercator"],PARAMETER["Fa lse_Easting",500000],PARAMETER["False_N orthing",0],PARAMETER["Central_Meridian",9 ],PARAMETER["Scale_Factor",0.9996],PARA METER["Latitude_Of_Origin",0],UNIT["Meter", 1]] Projection settings-1

18. Then, when applicable, the correct datum shift must be selected within ArcPad. Example “Enschede” : Projection settings-2

19. Prepare projection file-1 Select in ArcView a shapefile and start the “ArcView Projection Utility”. ArcPad 6 supported projections: Geodetic coords. (Lat-Long) Alberts Equal Area Conic Cylindrical Equal Area (Double) Stereographic UTM (TM; Gauss-Kruger) Lambert Conformal Conic New Zeeland National Grid

20. Prepare projection file-2 Start in ArcMap the “ArcPad Tools” wizard and export a *.SID image.

21. Images can be compressed by a factor 25!!! No need is left to prepare clumsy JPG's for ArcPad. MrSID images will do!! They hardly suffer from resolution loss when compressed, and can cover substantial areas ( the original IMG file must be < 50 MB). Example: an AP from Enschede is compressed from 25 to 1 MB. Shown is a fraction of the original image!! SIDIMG Compress Images

22. Performance in Hills Often, main roads are poorly mapped on GT- sheets, while (15m resolution) images of mountainous areas hardly show the roads. Digitizing roads by GPS in hills proved very useful and accurate enough to fill this shortcoming. Digitizing administrative boundaries in hills on foot using a GPS is not considered practical. Roads digitized in Ghazi RMS on top of a GT sheet and on an Aster image (Febr.2001; scale 1:25,000). Mapping in the Field-1

23. Mapping in the Field-2 Performance under trees Cycling to work during a cloudy morning provided the yellow line. It is projected on AP’s, an Ikonos image and the Top-10 of Enschede. Where high trees were present, tracking with the GPS give visible errors. ArcPad can provide accuracy warnings !!!

24. Mapping in the Field-3 Part of an old GT sheet and the new feeder canal under construction at Tarbela on a recent Aster image (Febr.2001); scale 1:25000. Use of GPS to check Image Geo-Referencing quality Outdated GT-Sheets can create problems while georeferencing images. Through the GPS-Ipaq set, digitized roads can be used to check if images are properly geo-referenced. The geo-referencing of the Aster image (Febr.’01) is clearly not matching required standards.

25. GPS-iPaq Warnings Not for GIS amateurs Requires user to know facts on projection systems ‘properly’ Requires proper preparation: of geo-referencing images of compressing images of converting shapefiles of preparing symbologies of preparing forms Requires proper GPS-ArcPad software settings Once all is done well….experience shows too many advantages and even a dependancy of using the equipment during fieldwork !!! The ArcPad manual is only 390 pages thick !!!

26. GPS-iPaq Hardware Parts

27. Hardware Alternative/future Trimble's GeoXM™ GPS CE handheld, from the GeoExplorer® CE series, combines a Trimble GPS receiver and a powerful Windows CE operating system into one rugged unit. The result is a convenient and versatile handheld that's perfect for mobile GIS applications. Prices starting at $2895. - 0.72 kg with battery 7 hrs battery life USB connectivity 128 MB Flash data storage 2–5 meter accuracy

28. Try-out files for Enschede