An Improved Doppler Parameter Estimator for Synthetic Aperture Radar

摘要

To achieve a high quality synthetic aperture radar (SAR) image, the motion caused by the radar and/or the moving target needs be compensated for coherent processing, and this requires the accurate estimation of the Doppler parameters of the received signals. A new, ap-proximate, maximum likelihood (ML) estimator in the time domain is obtained recently to jointly estimate the Doppler parameters, and it is shown to have much better performance than that of an existing approximate ML estimator in the literature, for the values of the Doppler parameters of interest. The effects of the parameter estimation errors on the SAR system performance are analyzed. By revealing the relationship between the range/azimuth resolution of SAR imaging and the estimation accuracy of the Doppler parameters, we show that our new estimator can be applied in SAR imaging to improve the image quality.