Advanced L-Band SAR System Concepts for High-Resolution Ultra-Wide-Swath SAR Imaging

Abstract

This paper reviews multichannel SAR instrument architectures, modes and processing techniques for the imaging of ultra-wide swaths with high azimuth resolution. The review includes both direct radiating arrays and reflector-based system architectures that are operated in either a single-transmit multiple-receive (SIMO) or in a multiple-transmit multiple-receive (MIMO) mode. The work has been conducted by DLR under the ESA contract -Advanced Processing Techniques for Next Generation Multichannel SARs- with the main objective to identify suitable SAR modes, processing techniques and system architectures for the definition and design of a next generation L-band SAR with unprecedented imaging capabilities. The goal is to map an ultra-wide swath of 400 km with 5 m azimuth resolution and to achieve, at the same time, an excellent imaging quality where both the noise equivalent sigma zero (NESZ) and the distributed ambiguity ratio (DTAR) are better than 25 dB. Towards this end, a large number of different SIMO and MIMO system candidates have been identified and assessed in view of achieving the demanding performance goals.