Co-registeration of multi-temporal PolSAR datasets

Microwave Toolbox
1

Hi everyone:
I’m confused about the co-registration when dealing with multi-temporal PolSAR datasets. Should I register each channel(VV, VH) individually and extract polarimetric parameters such as H, A, Alpha after that? I think the solution above is a little complex, do you have other better ideas?
Thanks for your reply in advance.

2

Sorry for asking, but why do you need them coregistered to a stack?

3

Sorry for my ambiguous description, I would like to do the classification by employing time-series polarimetric parameters. It seems that tutorials I find are aiming at single channel. So I want to find a solution about multi-channels.

4

I would then proess all products individually, apply Terrain Correction and then use the “create stack” tool.

5

Thanks for your reply, i’ve tried you method, it worked. But I still have 3 questtions:
1.I applied target decomposition to extract parameters after Terrain Correction, was that right?
2. Images were geo-coded after TC, did TC contain the back geocoding process?
3. Were the products after TC collocated accurately enough for creating stack? Or the errors could be ignored?

6
  1. No, Terrain Correction involves resampling. That means you no longer have information on the scattering mechanisms within your pixels. I would terrain correct after decomposition.
  2. I don’t think so but they have a coordinate reference now
  3. In many cases yes, but sometimes, you need to co-register the terrain corrected products to achieve good matches between your rasters.
7

Thanks.
I think terrain correction are intended to reduce the errors about topographical distortions, could the polarimetric parameters be used as the input? By the way, there are 3 kinds of methods in SNAP(range doppler TC, SAR simulation and SAR simulation TC), which one is applicable in this case?

8

SAR simulation TC only works when there is topographic pattern in your SAR image. This is not the case for polarimetric features so I recommend Range Doppler Terrain Correction. This should reduce the topographic distortions in your polarimetric features but keep in mind that information on layover or foreshortening areas is still considered lost.