RTK/GPS inject - Vertical datum

Sorry if this was asked before, but I can’t seem to find the answer in the forum. What vertical datum do we have to use in Mission Planner when using RTK/GPS inject? Ellipsoid (WGS84)? Ortho height (EGM)?

Use the WGS84 datum.

Ok thanks! However, I found that the Mission Planner uses Ortho height with the “Point camera Coords” function. It’s a bit misleading.

so this one is tricky.

if your using RTK, then the reported datum of the autopilot will likerly be the RTK datum, ie the standard non rtk is egm96

ie MP does no datum conversion, it what the gps device/datum source is telling the autopilot

all MP elevation data is in egm96(srtm)

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My mistake for making an assumption. I didn’t realize it was potentially a bit complex!

Thanks Michael. Follow up question, where can I see what vertical datum the autopilot is reporting? Looking at the flight log, the GPS altitude seems to be Orthometric unless the autopilot is internally making a conversion.

I thought that MP had something to do with it, but as MO said, MP just reads the GPS data.

You can login into your GPS (ie U-Center) if you have ublox and check the vertical datum from there. Most propably it is set to use EGM96, you can change it to ellipsoid heights or another vertical datum.


the autopilot does no conversion, the gps will be doing it. elipsiod wgs84, geoid egm96, this is assuming a standard ublox setup. if you do have a different gps, then its is whatever the gps is configured for. i have seen logs in pure wgs84, with no geoid