Residual Motion Estimation for Multi-Squint Airborne SAR

Airborne SAR data are often challenging to analyze due to the limited accuracy of the platform motion measurements. In interferometric scenarios, even small residual motion errors cause undesirable artifacts in the interferometric phase and geometric registration of image pairs. Various calibration techniques have been developed, often exploiting spectral diversity in some way. The UAVSAR L-band system has implemented a new operating mode where multiple images are acquired simultaneously at different azimuth squint angles, providing enhanced opportunities for motion calibration. This paper describes this imaging mode and the residual motion calibration technique developed for these special data sets.