I am writing a Sentinel- IW-mode image formation tool in Matlab. Although I have implemented the code according to my understanding of Sentinel-1-Level-1-Detailed-Algorithm-Definition.pdf, I have blurring occurring in my formed image as I move away from center azimuth in the azimuth directions. There are several possible causes. In attempting to verify my implementation of the Secondary Range Compression, I notice that my function makes only small change to the range vector that is input. I have no example of what to expect for the magnitude of change and/or the value of Ksrc(R,f_eta). Does anyone have ‘typical’ values for Ksrc they can share for all three subswaths?