Multi-Channel Azimuth Processing for High-Resolution Wide-Swath SAR Imaging

Abstract

Conventional Synthetic Aperture Radar (SAR) systems with a single transmit and receive antenna are not capable of simultaneously imaging a wide swath with high spatial resolution. New techniques employing multiple receive apertures to overcome this system-inherent limitation are examined in this work, with particular emphasis on multiple channels in azimuth. The work introduces an innovative processing algorithm that is suited to cope with the multi-channel data. Comprehensive analysis of this novel “multi-channel reconstruction algorithm” covers the theoretical investigation of its impact on system performance as well as its verification with measured and simulated data. The simulation results are given in the context of a complete high-resolution wide-swath SAR system design which highlights the intricate relationship between system architecture and multi-channel processing. Subsequently, different innovative optimization strategies to improve the system performance and increase the operational flexibility are demonstrated and theoretical analysis is extended to these approaches. Furthermore, multi-channel systems operating in burst modes such as TOPS (Terrain Observation with Progressive Scan) and ScanSAR are investigated as a solution to new imaging modes enabling for compact antenna dimensions an unprecedented combination of an ultra-wide swath with reasonable geometric resolution in azimuth.