I am working on creating deformation map.
But I need to mask out areas with low coherence from the final map (or even during the early stages of the process).
Can you please help me on how to do that? I need to exclude areas with coherence of less than 0.6.
use the valid pixel expression as described here: Subsidence map in 3d view
I used the valid pixel expression.
Then I saved the unwrapped phase product which looked like:
Then I conducted phase to displacement:
Then: Range doppler terrain correction, which gave:
Now the thing is that, wasn’t the areas that had coherence<0.4 supposed to be “blank”?
you have to include the coherence in the terrain correction step (select this band also) and then enter the valid pixel expression again after the terrain correction.
But when conducting “Phase to displacement”, it removes all the bands and creates only a band “displacement”, which makes it impossible to use “cohIW2…jan2015>0.4” in valid expression.
Therefore, in range doppler terrain correction, there isnt any option that allows us to use coherence.
Also, absence of coherence band in terrain-corrected displacement gave error:
Also, I tried terrain correction for unwrapped phase, used valid pixel expression to remove low coherence areas in unwrapped phase, and then conducted “phase to displacement”, but it gave an error “Source product should not be map projected.”
That means that Terrain-correction should be the last step.
@mengdahl Yes that it is.
But I think I figured this out. So basically I terrain corrected 1)Displacement 2)Unwrapped phase.
And then I collocated them (stacked), and then I applied valid pixel expression of coh>0.4 on the displacement. And I believe the result is good. What are your thoughts on this @ABraun?
that’s the solution to get both rasters in one final product.
The result looks fine - hard to tell without knowing where it is. You might try File > Export > Other > View As Google Earth KMZ and display it on a Google Earth basemap to put it into perspective.
Sounds awesome. Thank you so much @ABraun.