Fail to run sar-simulation terrain correction

Hi, I tried to geometric correct cosmo-skymed data using sar-simulation terrain correction technique but my output is black (nothing). Could anyone tell me why?

this can have several reasons. Please give us information on the following questions.

  • No auto-download DEM is available in your area (where is it located?)
  • SNAP cannot access the DEM directory (some things changed recently, are you sure you have installed all updates?)
  • No topographic patterns are reflected in your intensity (do you have topography within your area?)
  • The spatial resolution of the downloaded SRTM doesn’t reflect the variations in the image (which one did you select and what’s the spatial resolution of yur CosmoSkyMed data?)
  1. DEM is available at Skudai, Johor, Malaysia
  2. Yes, I ave installed recent updates
  3. Yes, my area have topography
  4. I downloaded the 90m SRTM and my spatial resolution of COSMO-SkyMed is 3m

you could reduce this discrepancy by using the SRTM 1 ArcSec (AutoDownload) which has a spatial resolution of 30 meters. If the patterns in the image are not represented by landforms in the simulated image, the coregistration fails. As a check, you can run the SAR Simulation (without TC) and have a look at the simulated SAR image. If it is comparable to your input data the terrain correction should work.
Otherwise you will have to go for Range Dopper Terrain Correction.