A single-channel SAR-GMTI algorithm based on sub-apertures and FrFT

This paper investigates sub-image cancellation for ground moving target indication (GMTI) with a single-antenna airborne synthetic aperture radar (SAR). First the paper points out how to choose the sub-image from the whole image. After the generation of the sub-image, the imaging difference of stationary object and moving object in the sub-image based on the frequency division is analyzed. Once the detection is completed, the moving target is still dispersed and the FrFT(Fractional Fourier Transformation) algorithm is chosen to focus it. Using FrFT algorithm, the doppler modulation rate can be obtained so that the azimuth velocity of the moving target is estimated in this way. The theoretical analysis and simulation results demonstrate that the method is effective and can not only detect the moving targets but also estimate their motion parameters precisely.