Low-Loss Synthetic Aperture Radar (SAR) Data CompressionComplex SAR Image Compression for Automatic Exploitation

SAR (Synthetic Aperture Radar) systems have proved to be invaluable for many applications, both military and commercial, including automatic target detection and recognition (ATD/R), terrain mapping, change detection, battle damage assessment, and moving target refocusing and detection. The proliferation of SAR systems, along with the dramatic increase in on-board data gathering and processing rates, places an onerous burden on the communication links that transmit SAR data to groundstations for analysis. SAR-specific data compression may alleviate this problem, but compression must not adversely affect downstream automatic exploitation applications (e.g., ATR) that must mine the data for information. These applications require not just the viewable SAR magnitude image, but the full complex image. Previous SAR compression work is lacking in that it deals only with magnitude imagery, and does not measure the effect of compression-induced degradation on downstream applications. ALPHATECH proposes to use innovative approaches to complex SAR compression to develop real-time capable, deeply-compressing algorithms tuned to SAR exploitation applications. Key to algorithm design is an upfront analysis of exploitation application sensitivity to compression-induced degradation, where we quantitatively measure sensitivities by playing degraded imagery through ALPHATECH-owned exploitation applications, including ATD/R, registration, coherent and non-coherent change detection, super-resolution and moving target focusing.