Burst Mode SAR's for Wide Swath Surveys

A spaceborne SAR is proposed, aimed at global monitoring with a short revisit time (12 days). Such a system is not feasible in a conventional STRIPMAP mode, due to the known relation between range coverage and azimuth antenna length. However, it can be achieved in burst mode SARs, like ScanSAR and TOPSAR. We detail the design of ScanSAR and TOPSAR sensors, we provide a scheme to optimize the burst length in TOPSAR, and finally we discuss an innovative burst-mode scheme, defined as TOPSSPOT. The performances of the three schemes are analyzed in terms of scalloping, Noise Equivalent Sigma Zero (NESZ), and ambiguities and are validated with simulated results achieved by assuming point targets on the ellipsoidal earth.