A new multi-channel SAR-GMTI algorithm based on DPCA-FrFT is proposed

which can work on raw data and SAR image.According to the chirp characteristic of DPCA signal

we introduce the FrFT to detect the moving target and estimate the position

velocity and radial acceleration of the moving target

which lead to an overall and accurate description on motion parameters.Then according to the parameters

we apply the FrFT to compress the raw data on azimuth direction

or repositioning and focusing the moving target in the original SAR image.The proposed approaches take the full advantage of the excellent antinoise ability of the FrFT and ideal clutter cancellation of DPCA technique

and an exact SAR-GMTI image can be acquired in a clutter-rich and low SNR environment.The results of the simulation indicate the efficiency and availability of the methods.