Problems for S1 coherence estimation

We want to estimate the coherence (modulus of the interferometric coherence) over the region of Paris.
We succeeded to estimate it (with SNAP software) for the period extending from March 2015 to May 2016.
But since May 2016 there are some problems. And since September 2016 the coherence estimation leads every time to a totally black image (DN =0).
this is an example of 2 products:
The products are:

did you visually check if the coregistration was successful?

no when i should do the coregistration?

you can only calculate coherence between two images if they are co-registered correctly.

Please have a look here:

yes i do it but the same result

sometimes a band gets lost during the coregistration. You can make an RGB-composite to see which ones are included and how good they match.

ok thank you its work

I am using two S1 SLC images (S1A_IW_SLC__1SSV) to estimate the coherence for urban footprint mapping. Ive applied orbit file, split them and co-registered. After running coherence estimation. I am getting the output. But the output is not getting displayed in the window. I am working in a RUS Virtual Machine. Where did I go wrong?

I guess the problem is not with coherence estimation, but with the co-registration. When I do the co-registration, the slave image just becomes blank…any idea?

can you please name the full names of the two products?

I am really sorry to bother you. I just updated SNAP and got the results. Thanx :slightly_smiling_face: