Dual-speed SAR imaging of moving targets

In conventional synthetic aperture radar (SAR) systems, the image of a moving target is usually mis-located. This is because the Doppler shift of the moving target is determined not only by its geometric location but also by its velocity. After range compression and auto-focusing, the Doppler frequency of the moving target is still time varying and the Doppler centroid is shifted. As a result, the SAR image of a moving target is smeared and the image location of the target may not reflect its true geometric location. In this paper, a dual-speed SAR imaging ap proach, i.e., the radar platform flies with two different speeds in the radar observation time duration, is proposed to resolve the above two problems, especially mis-location of a moving target.