High Resolution Wide Swath SAR Imaging - System Performance and Influence of Perturbations

Abstract

The displaced phase centre (DPC) technique enables a wide swath SAR with high azimuth resolution. In classic DPC systems, pulse repetition frequency (PRF), sensor velocity and antenna length underlie a stringent timing requirement to en­sure uniform sampling of the syn­thetic aperture. This constraint can be overcome by the use of a recon­struction algorithm, which enables a recovery of the unambiguous azimuth (Doppler) spec­trum also in case of a non-uniform sampling. This paper illustrates the principle of the reconstruction and ex­plains its limitations and the impacts on the ambiguity suppression. The potential of the algorithm when applied to DPC systems like TerraSAR-X with its split receive antenna is demon­strated and the benefits re­sulting from th e additional receive ap­erture re­garding swat h width and resolution are pointed out. Further on, the impact of ad­ditive and phase noise on the recon­struction and its sensitivity against these perturbations are shown.