So you have collected your sample site locations with a Garmin GPS 60 and now you want to process them in ArcGIS or MS Excel?
On your own computer: Install a converter
To convert the data from the GPS unit to ArcGIS we recommend the “DNR Garmin” converter. On University PCs it is already installed. For your own PC, download it from http://www.dnr.state.mn.us/mis/gis/tools/arcview/extensions/DNRGarmin/DNRGarmin.html. Installation instructions are provided on the website.
Download and convert the GPS data
- Connect the GPS device to your PC’s USB port and switch it on.
- Wait for a minute to give the driver time to install.
- Start DNR Garmin (Start > All Programs > DNRGarmin)
- Go to GPS > Set Port and make sure the USB port is selected. DNR Garmin should show GPS60 Software Version… as above. This verifies that the GPS is detected. If it is not detected, go to GPS > Open Port, and if that does not help, close and restart DNR Garmin.
- If you want to download waypoints from the GPS, go to Waypoint > Download.
- If you want to download tracks from the GPS, go to Track > Download.
- Click the Data Table button, then select the Waypoint or Track option to list the data.
- With your type of data selected (waypoints or tracks), go to File > Save To > File…, a Save As window opens
- Navigate to the folder where you want to save the data, e.g. My Documents.
- At the bottom of the window select the file type you want to save your data to:
- For ArcGIS select ArcView Shapefile (Unprojected) (*.shp).
- For MS Excel select Text File (comma delimited) (*.txt)
- For databases select Text File (comma delimited) (*.txt) or whatever format your database software can read.
- Enter a filename, e.g. MyGPSdata
- Click Save.
View the data
Start the application you want to use the data with (ArcMap, MS Excel, MS Access, etc.) and load the file.
With ArcGIS: convert coordinates to British National Grid
Note that your coordinates are geographic (decimal degrees), referring to the WGS 84 datum.
If you want to overlay your data in ArcMap with data that uses a different datum, like UK Ordnance Survey data, follow these steps:
- In ArcMap or ArcCatalog open the toolbox and start the Project tool (Data Management Tools > Projections and Transformations > Project)
- For Input Dataset select your Shapefile containing the GPS data, e.g. gpsdata.shp.
- The Input Coordinate System may be set automatically to WGS1984, otherwise select it (Geographic Coordinate Systems > World > WGS 1984).
- Set a location and name for the Output Dataset, e.g. gpsdata_BNG.shp.
- Set Output Coordinate System to British National Grid (Projected Coordinate Systems > National Grids > Europe > British National Grid).
- For Geographic Transformation select the first option. Do not leave blank.
The output file contains coordinates in British National Grid, referring to to the BNG’s underlying datum OSGB 1936. It will overlay correctly with UK Ordnance Survey data that uses the same datum.
Very technical note: the DNRGarmin software also allows you to download the data in a projected coordinate system, saving you the ArcGIS projection steps. However, the DNRGarmin software by default uses a geographic transformation for WGS84 > BNG that is different from the ones used by the OS. Therefore data downloaded as ‘projected’ will not overlay correctly with OS data.
Alternative converter: GPSBabel
GPSBabel does not support shapefile creation, but more other output formats than DNRGarmin.
- Go to www.gpsbabel.org, download the gpsbabel*.zip file, and extract it to any directory, e.g. My Documents\gpsbabel\.
- Connect the GPS to the PC’s USB port and switch it on.
- If a driver installation starts, wait until it completes.
- Open the folder where you extracted GPSBabel, e.g. My Documents\gpsbabel\ and double-click the file GPSBabelGUI.exe.
- In the Input section:
(1) Tick the Device option.
(2) Select Garmin serial/USB protocol
(3) Select USB
- In the Output section:
(4) Select whichever output format you require, e.g. Keyhole Markup Language for Google Earth KML/KMZ files.
(5) Type a path and filename for the output file or use the (6) button to specify the output file
- In the What? section:
(7) Tick the Waypoints and Tracks options. (Depending on output format not all options might be available.)
(8) Click the let’s go button to start processing the data
- After the data is processed GPSBabel displays a message. Close this message and also close GPSBabel.
- Switch the GPS device off and disconnect it from the PC.