This may be a bit off topic because it’s related to the SW Maps software that’s recommended for the RTK Facet, but here goes:
This software appears to only work in ellipsoid elevations. It doesn’t display or record Orthometric height, i.e. the elevations that surveyors use. The difference in my area is about 100’. Am I missing something?
Be sure to enter the ARP offset for the antenna and device height https://docs.sparkfun.com/SparkFun_RTK_ … e/#sw-maps
Then you should be able to export gtx/geoid format that includes orthometric height https://community.opendronemap.org/t/sw … at/10383/5; the last post in that thread also mentions a conversion tool if needed (‘eye4software’)
Orthometric heights don’t change much. Find out your antenna’s true geodetic position and then force that onto the fixed base station mode with orthometric heights. You can do PPP coverage across the largest extent of your site and see what the change in orthometric elevation is. It’ll likely be a constant difference when subtracted from ellipsoidal heighs.