Earth observing SAR data processing systems at the Jet Propulsion Laboratory — SEASAT to EOS SAR

Abstract

This paper traces the evolution of SAR digital data processing and management systems developed at JPL for earth science missions. The Interim Digital Processor (IDP) was developed for SEASAT SAR, utilizing a general-purpose mini-computer and commercial array processors. The IDP established the fundamental algorithms for SAR data correlation but performance was inadequate for an extended mission. To increase performance, JPL undertook a research program to develop the Advanced Digital SAR Processor (ADSP) which implemented a frequency-domain correlation algorithm in custom hardware and was capable of processing 50 megabits per second. The ADSP design was subsequently used in a lower-throughput system recently installed at the University of Alaska, Fairbanks. The SIR-C and RADARSAT missions, however, will employ SAR processors based, to the maximum extent possible, on general-purpose, commercially-available computing components. Beginning with the European Earth Resources Satellite (ERS-1), routine geophysical products will be made from SAR data. A prototype system was installed at the Alaska SAR Facility which will routinely generate ice motion and ice type maps. The SIR-C ground processing system and the Alaska SAR Facility are important precursors for EOS SAR, which will have an order of magnitude greater processing requirements.