Height bug

From OpenTom
Jump to: navigation, search

Some Tomtom GPS-Chips (see table below) tell the height above WGS84 ellipsoid instead of producing the height above sea level (ASL). The difference between the height ASL and that above WGS84 ellipsoid is not constant (varies between -106 m and +85 m [1]) although it varies quite smoothly. The correction for a particular position can be obtained with the online geoid calculator.


TomTom Models with the height bug
Model height bug Option for TTTracklog Option for Height Option for GPSBabel
TomTom ONE 3rd Edition YES --agc h-48.4 -x height,wgs84tomsl
TomTom GO 520/520T NO none h0.0 none
TomTom GO 720/720T NO none h0.0 none
Note: the option for Height is an example where the correction needs to be -48.4 m.
Personal tools