A Novel Algorithm for Doppler Frequency Rate Estimation of Spaceborne Synthetic Aperture Radar
Synthetic Aperture Radar (SAR) can obtain high-resolution radar images under all weather, day and night and long distance conditions, and has been applied widely in military and civil fields. Range-Doppler (RD) algorithm is a simple and typical imaging algorithm. The key of it is Doppler parameters estimations, including Doppler centroid frequency and Doppler frequency rate. Doppler frequency rate is variational with range. If the estimation of it is inaccurate, it will bring severe defocusing effect and blurring in azimuth direction. The previous estimations of Doppler frequency rate usually use image field instead of data field, the calculated amount is very large and the imaging speed is slow. In order to improve them, this paper proposes a novel Doppler frequency rate estimation algorithm for spaceborne SAR imaging. The raw data of ERS are used to test effectiveness and feasibility of this method.
KeywordsSynthetic Aperture Radar Synthetic Aperture Radar Imaging Account Scalar Autofocus Algorithm Spaceborne Synthetic Aperture Radar
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