Adventures in SAR processing

摘要

Abstract: The image formation process associated with coherent imaging sensor is particularly sensitive to and is often corrupted by non-stationary processes. In the case of SAR, non- stationary processes result from motion within the scene, variable radar cross section, multi-path, topographic variations, sensor anomalies, and deficiencies in the image formation processing chain. Conversely, stationary processes result in image signatures that appear literal to the eye, e.g., urban infrastructure, vegetation, and natural terrain. In analyzing SAR signal history two objectives unfold. One is to obtain a well-focused image devoid of distortions and non-literal artifacts. The second objective is the detection and value-added exploitation of the non-stationary signatures. Note that the roles of signal and clutter are reversed for these two objectives. The notion that joint time-frequency (JTF) techniques may prove useful in accomplishing these objectives has spurred limited investigations into the field of coherent radar imaging systems. This paper addresses SAR image formation processing, the complex response function for a point source, and SAR JTF image formation implementations. Each of these topics is described within the context of applying JTF processing to all aspects of SAR image formation and analysis. !17