The default no data value is usually 0 in products. Right click on the band and open the properties. Uncheck use no data value. If these are valid zeros then with this unchecked you should be able to use them as you wish.
If it’s not using the no data value, I’m not sure where NaN could be
introduced.
Please provide the type of product being used and what processing was
applied to it.
Sir, its SSC product of TerraSAR-X. When I apply Radiometric calibration to it, the product generated contains many NaN values. I don’t know how to troubleshoot it.
Sir, when I open the properties of any of the calibrated TSX products generated from the SLC product, No data value is checked. Do I need to uncheck before proceeding further for coherency matrix generation and decomposition?