Hello,
I am trying to create a SAR coherence image over some glaciers in the Himalayas in order to map debris-covered ice. I have downloaded two Sentinel 1 images of my area in IW format. When I am co-registering the data before carrying out all the steps to make a coherence image, what is the appropriate method to choose? I tried doing the S1 TOPs co-registration (with and without ESD) but I was concerned that the latter uses cross-correlation which I guess is not appropirate with an area containing flowing ice.
Does anyone have any suggestions on which method is the most applicable to use for a glaciarised area?
Coregistration of data (Corregister TOPS Corr. And ESD Both are possible)
Interferogram Formation
TOPS debursting
Topographic phase removal
Goldstein phase filtering
Multilook [10 (range); 2 (Azimuth)] for filtere5d phase;
Reconstruct the phase after Multilooking by using the Band Maths Op;
Export the result of step 4 to SNAPHU
Export by SNAP to Unwrapping
Import the result of SNAPHU
11 - phase to displacement
Range-Doppler Terrain Correction
Export the result of step 10 as a KMZ
NB/ Either you could end up your processing until the step 7 by getting the coherence map, Or you could continue until to get the Differential Interferogram
It says in the help file that the ESD uses cross correlation to co-register the images - that is why I was thinking for setting where you may have significant changes between the two images, ESD was not appropriate?
What is the Band Maths Op and why is it necessary?
In case your study is within one Burst, then you could use TOPS Corr., However, in case your study area is located within two bursts, then in this case use ESD to avoid jump in phase, but the ESD is only used in low deformation rate, However, there is a solution in case your study area is located within two bursts or more, besides the high deformation rate, then you could apply ESD to one image and follow this step by Corr. using TOPS corr.,
Use to enhance the visualization of your image only (In this case).
Great. It all seems to be working. I am not interested in the DINSAR displacements, just coherence, so I was wondering if the band op influences the coherence image or just the phase? Also do you have more details on the band op?
As I explained to you previously, the band op (In this case) is only to enhance the visualization of your image, and your orginal data should be used, to get the real results of coherence.