I have two GPS units - a Garmin Colorado and a eTrex. Both of them allow me to choose between different datums. Which datum should I use for OpenStreetMap? asked 06 Jul '10, 17:44 Andy Allan |
All Garmin GPS devices always record the tracklog and waypoints in WGS84, no matter what you have the datum set to. All the datum setting changes is the numbers displayed on the screen, and the NMEA output. So unless you are using the NMEA output, you can set the datum to whatever you like, eg you can set it to your local grid and datum to relate to other maps. If you're using the NMEA output, you should know what you're doing, and have your receiving software set to the correct datum. Note: while this is true for Garmin, other brands may vary, and might record the tracklog in different datums. So check this before using with Openstreetmap. answered 10 Jul '10, 22:45 Vclaw |