How do I process satellite image stereo pairs with an RPC model?
Posted: Thu Feb 05, 2026 9:23 pm
by yoshihiko_nakanishi
I created a DSM by inputting a satellite stereo pair with an RPC model, but the output is in ellipsoidal height.
How can I output it as elevation?
Re: How do I process satellite image stereo pairs with an RPC model?
Posted: Fri Feb 06, 2026 11:27 am
by David Alamillo
When generating a DSM from satellite stereo imagery using RPCs in Correlator3D, the output elevations are initially referenced to the ellipsoid because the RPC sensor model is based on an ellipsoidal height system (typically WGS84).
To output the DSM as elevation (orthometric height), you simply need to apply a geoid correction so the heights are referenced to mean sea level rather than the ellipsoid.
In Correlator3D this can be done during export:
Go to the DSM export settings.
In the vertical reference section, select the option to apply a geoid model.
Choose the appropriate geoid for your project area (for example EGM96 or EGM2008).
Export the DSM — Correlator3D will automatically convert ellipsoidal heights to orthometric elevations using the selected geoid.