Performance Studies of Emulated Multichannel SAR for Motion Characterization

Conventional single-channel synthetic aperture radar (SAR) cannot directly measure or correct for smearing and distortions due to scene motion. Previous theoretical efforts have pointed out that this deficiency can be overcome using an along-track multichannel SAR (MSAR), but lack an experimental foundation. In this paper we conduct in-depth sensitivity studies that characterize and demonstrate the robustness of an MSAR system for scene motion characterization. These include novel experimental studies that build on our previous work in MSAR emulation. Of significance, to our knowledge this is the first experimental verification of removing motion distortions in shoaling ocean waves using such an MSAR system. We also introduce a new processing mode for MSAR systems called SAVSAR (subaperture velocity SAR), which affords us a much wider range of options in adjusting the spatial and temporal resolution capabilities of MSAR imaging. The insights gained in this paper provide guidance on the choice of suitable configurations and processing methods for scene motion estimation using airborne MSAR systems.