A fast autofocus algorithm for synthetic aperture radar processing
نویسنده
چکیده
Synthetic Aperture Radar ( S A R ) has become a valuable instrument with applications in reconnaissance and remote sensing. High resolution SAR imaging requires the motion of the radar platform to be known very accurately. Otherwise phase errors are induced in the processing of the raw S A R data, and bad focusing results. In particular, a constant error in the measured along track velocity or the cross track acceleration leads to a phase error that varies quadraticly over the synthetic aperture. The process of estimating this quadratic phase error directly from the radar data is termed autofocus. This paper presents a novel autofocus algorithm with a computational complexity which is at least an order of magnitude lower than that of other algorithms providing comparable accuracies. The new algorithm has been tested on data from the Danish airborne SAR, and the performance has been compared with that of the traditional map drift algorithm.
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