Preprocessed S1 image outputs 0 value


I preprocessed S1 image by command line using XML file. I have done calibration, speckle filtering, terrain correction and linear to/from db. I saved output as tif file and wanted to read it with rasterio. However, rasterio showed array with zeros. What problem can it be?

Screen Shot 2021-07-22 at 15.45.44

that was no data area