Dual-speed SAR imaging of moving targets

In conventional synthetic aperture radar (SAR) systems, the image of a moving target is usually mislocated. 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 approach, 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 mislocation of a moving target.