Estimating the impact of the ionosphere on space-based SAR autofocus using GPS signals

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Authors

Colleges, School and Institutes

Abstract

Low-frequency space-based synthetic aperture radar (SAR) can suffer from the degrading effects of a scintillating ionosphere, which modulates both the phase and amplitude of the radar signal. In this paper, we use the received signal from GNSS receivers to simulate the effect of the ionosphere on a point target. The process for transforming the one-way GNSS signal, which contains a variety of signal biases and geometric factors, is described. Data recorded on Ascension Island during scintillation events is then used to determine the peak to sidelobe ratio (PSLR) that would be obtained from a SAR. A phase correction is applied to one GNSS receiver using another located along a magnetic east-west baseline. It is shown that this improves the SAR point spread function (PSF) and the variation with baseline distance is illustrated. It is concluded that, up to a baseline distance of at least 2305 m, the phase correction improves the focus.

Details

Original languageEnglish
Title of host publication2014 31th URSI General Assembly and Scientific Symposium, URSI GASS 2014
Publication statusPublished - 1 Jan 2014
Event31st General Assembly and Scientific Symposium of the International Union of Radio Science, URSI GASS 2014 - Beijing, China
Duration: 16 Aug 201423 Aug 2014

Conference

Conference31st General Assembly and Scientific Symposium of the International Union of Radio Science, URSI GASS 2014
CountryChina
CityBeijing
Period16/08/1423/08/14