Problem in exporting Sentinel 1 data

Microwave Toolbox
#1

Sir, I have a Sentinel 1 IW GRD Data and I have processed the data using the steps of apply orbit file , thermal noise removal, border noise removal, calibration, speckle filtering and terrain correction. I wish to do a band fusion with optical bands in Erdas Imagine which are in .img format.

So, after processing when I export the final product in geotiff (snap gave an error that file size is too big…so i exported using BIGTIFF)to open in ArcMap, the product is almost completely black. So what could be the possible reason about it?

Also, is it good to work with the .img files in the .data folder of terrain corrected image? Like what’s the difference between this .img files and the exported data?
Your insight will be highly helpful sir.

#2

probably the color contrast. Please make sure to scale the data between 0 and 1 (in case of linear Sigma0) or -30 to +5 (in case of db scaled data).

I recommend to directly use the img files in the data folder because any conversion between file formats (export to BigTiff) should be avoided if possible.

#3

Sir, thank you for your reply…
but is there any difference between the exported file in BIGTIFF and the direct.img file I am getting from it?
Because I would like to fuse it with optical data for my project purpose which are in .img format only.
And sir how to do that rescaling which you just mentioned?

#4

the difference is the file size and probably the file type (32bit int to 16bit int, for example) which can potentially lead to errors.

This is only a visual thing, the pixel values are not changed by this. Only the color ramp: https://desktop.arcgis.com/en/arcmap/10.3/manage-data/raster-and-images/stretching-a-raster-to-improve-the-visual-contrast.htm

1 Like
#5

Thank you so much for your answer and time sir.