I am trying to generate DIGITAL HEIGHT MODEL (DEM) using KOMPSAT 5 interferometric sar image pairs in SNAP 9.0.0 version. However, I encounter errors up to 100 meters in all the products I produce. My process steps to generate DEM; Import-Coregistration-Interferogram Formation-Goldstein Phase Filtering-Snaphu Export (TILE 10-10)-Snaphu Unwrapping-Snaphu Import-Geometric Terrain Correction Range-Doppler Terrain Correction consists of these. Are there steps I am doing wrong or generating a different DEM for KOMPSAT 5 Sar satellite?
I have not used KOMPSAT5, you can first do some literature survey about using KOMPSAT5 for DEM generation.
I have used Sentinel-1 for generating DEM, from my experience and other papers, Sentinel1 is not suited for this application, the error is large especially in mountain area, even if short perpendicular baseline and short time baseline are satisfied.
One of the main problems is the acqusition time difference of the two images( at least a few days), which causes discorrelation and may influence dem results a lot. If you look at the current DEM products, like STRM and TanDEM, they all have two sensors, the discorrelation caused by time baseline is negeiable.
So I am not optimistic about good dem results generated by KOMPSAT5, if you really want to do this, choose perpendicular baseline between 150-300m, and time baseline as short as possible. And if the area you choose is coverd by trees, sometimes the discorrelation with be severe especially for your X band data, no good results are expected