volume | PIER Journals

Abstract

Compared to low Earth orbit (LEO) synthetic aperture radar (SAR), geosynchronous (GEO) SAR has a larger coverage and shorter revisit period. However, due to its longer integration timeit will be affected byionospheric time-variant total electron content (TEC), which introduces a phase error into the SAR azimuth signal.Using U.S. total electron content (USTEC) data, TEC variation with timeon GEO SAR trackis analyzed. It is shown thatquadratic phase error caused by time-variant TEC is main effect on image focusing compared to higher order errors. Therefore, contrast optimization autofocus (COA) algorithm can beusedfor compensation. The key steps of COA are given. Simulations based on scenes derived from PALSAR2 data demonstrate the effectiveness of COA.

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Dr. Xingyu Liang

Dr. Zhuo Li