isce-framework
Copernicus DEM for ALOS-2 ScanSAR coregistration
By default, ISCE2 uses the SRTM DEM whenever no input DEM is specified. If a Copernicus DEM is to be used, it must first be corrected, converted to ISCE format, and properly referenced in the input configuration file.
I obtained a Copernicus DEM for the area of interest using SARDEM and applied geoid correction, then converted it to an ISCE-compatible format. Despite this, the software does not accept the DEM for geocoding and coregistration. Previously, I tested a Copernicus DEM with topsApp.py, which worked correctly; I recall having to manually flag the WGS84 datum in the DEM XML file to prevent ISCE from reapplying geoid corrections. However, I am unsure why the same approach is failing for ALOS-2.
Any insights or suggestions would be greatly appreciated.
<property name="dem for coregistration">/copernicus-ALOS2/DEM_ALOS2.wgs84</property>
<property name="dem for geocoding">/copernicus-ALOS2/DEM_ALOS2.wgs84</property>
Error log
The remaining steps are (in order): ['slc_match', 'dense_offset', 'filt_offset', 'geocode_offset']
Running step slc_match
2025-09-10 12:30:37,970 - isce.zerodop.topozero - WARNING - Default Peg heading set to: -2.900164920415836
Polynomial Order: 0 - by - 0
0
Polynomial Order: 0 - by - 1
833456 8.58253
GDAL open (R): DEM_ALOS2.wgs84.vrt
ERROR 4: DEM_ALOS2.wgs84.vrt: No such file or directory
terminate called after throwing an instance of 'std::runtime_error'
what(): Cannot open the file DEM_ALOS2.wgs84.vrt in read mode.
Aborted (core dumped)
The directory and vrt files are both available though
