Back scattering

hello everyone:
I want to get back scattering of pixels in a large number of sentinel-1A images.
The current operation steps are: pre-processing the data by SNAP or ENVI software, and then extracting the backscatter of the target pixels in each image. The whole data preprocessing process takes a lot of time.
If the backscatter is obtained directly from the original data ( SLC or GRDH ), the extraction of the backscatter information is realized through programming, which requires those parameters in the source file?