How do i generate a Gradient Image on S1tbx?

Hello everyone. I’m actually trying to generate a Gradient Image (maximum absolute variation between consecutive acquisition dates) in a time series of Sentinel-1 images. In the function Stack Averaging (Radar>Coregistration>Stack Tools> Stack Averaging) doesn’t have this operator. Usually i’ve tried to do this manually in band maths, but i’m not sure if the result is okay. So, does anyone else know how to do it?