when I processing a multi-master images graph,the result is that PS coherence are very low much of them below 0.3. I don’t know why, but this is wrong. Can you tell me the reason? Thank you ! some pictures in attachments.
What do you mean that this is wrong? How can you say it’s wrong?
Don’t be afraid that a temporal noise in this case is not corresponding to a spatial noise.
In space you are applying several smoothing operations (interferogram filtering, unwrapping, APS estimation)
so, it is reasonable to expect a spatial correlation in the results
the problem is that the temporal model is not matching well your observations + estimated APS.
One key question is:
are the vel/dem patterns matching those estimated in the APS module?
if the answer is negative, the result is unreliable
if the answer is positive, it means that the whole process is consistent.
check well the unwrapped interferograms, the spatial graph and the estimated APS in the APS module: those are the starting points of the whole process…