Calculate the ratio of the backscatter coefficients


I have three S1 SLC datas(different times),and I want to calculate the ratio of the backscatter coefficients between them.The processing steps I am using is as follow:

  1. calibration
  2. Deburst
  3. Multilook
  4. speckle filtering
  5. Terrain Correction
  6. DEM-Assisted Coregistration

But there would be a error ‘0’ when I run DEM-Assisted Coregistration.What’s wrong with my processing steps?And what should I do next?

Thank you!

what DEM did you use for the coregistration? Maybe your images are outside the SRTM coverage?

image source

SRTM 3Sec.And my study area is In China,Altai Mountains .


I found if I input the images (calibration->Deburst->Multilook) when I run DEM-Assisted Coregistration, there wouldn’t be a error ‘0’.And now it is running slowly,I haven’t got the results yet. :flushed:

If it works fine,can I keep doing Speckle filtering and Terrain Correction?And compared to the DEM-Assisted Coregistration,maybe I can also run coregistration->stack tools->create stack ?(I saw this from other post)

for SLC data, this is not exact enough. I suggest using GRD products, apply Calibration and then Coregistration and in the end Terrain Correction.

SLC data is only suitable if you need the complex pixel information.

Thank you for your answer!
Because I also want to run H/α decomposition,so I choose to use SLC data.
And for SLC,if now I need to calculate the ratio of the backscattering coefficients between three images(different times),could you tell me a complete processing procedure?

you find suggestions for both products here: Radiometric & Geometric Correction Workflow

Thank you!