Height
Ellipsoidal and orthometric heights.
This group converts between a GPS height above the ellipsoid, a height above mean sea level, and a height above the ground you give. Drone operators, surveyors, and GIS analysts use it to line up GPS heights with maps and terrain. Start with the height conversion. The classic mistake is reading a GPS height as elevation, which can be off by tens of meters: about 28 m in central Kansas.
I want to turn a GPS height into a height above sea level, or back
- Ellipsoidal and orthometric height
Converts a GPS ellipsoidal height to height above mean sea level (orthometric) or back, with h = H + N and the EGM96 geoid height N.
Guides that use these tools
- GNSS control to OPUS to state plane: An OPUS position in ITRF2020 to NAD83(2011), then state plane coordinates, the orthometric height, and the combined factor for ground distances.