Remove water bodies from subsidence map


Hello, I have created a displacement map, and after removing areas with low coherence, I interpolated the whole surface using subsidence obtained from high coherence point.
But, I do not want to show subsidence/uplift in water bodies. So how do I do that? I know using water index to satellite image can be done to identify water bodies, but what do I do after that? Certainly creating polygons for each water body is not possible in my case. I want to produce maps like one shown in the figure.
Any help will be appreciated.
Thank you :slight_smile:


if you manage to create a water mask based on the intensity, you could use it as a valid pixel expression.
For example, you create a binary raster by applying a threshold on your backscatter intensity in the band maths:
Sigma0 < 0.05
This would result in a raster product (lets call it ‘watermask’) where 1 is water and 0 is no water (depending on the threshold).
if you then enter this in the valid pixel expression of your displacement you can formulate
watermask == 0
which then makes all areas of water transparent.

Have a look here on the generation of water masks:

Where is the image from by the way? Looks very nice!

Edit: A second option is “Land/sea mask”, but as this uses a comparably coarse DEM, it won’t bring satisfactory results.


You mean I’m supposed to apply band math in a band “Intensity_ifg_VV…”?


Oh and that image is from an Arctic area, got from google. No sure about the details. Looks great though.


yes, but thinking of it, the intensity in the interferogram stack has quite poor contrasts. You could apply a log transform to it (right-click > convert to db), to increase the contrasts between black water and bright land.