A Novel Algorithm of Radial Velocity Estimation for MC-HRWS System

In multiple channels in azimuth high resolution and wide swath (MC-HRWS) SAR system, the azimuth signal reconstruction of moving target based on the space-time equivalent sampling principle exists a periodical phase error on account to the radial motion of moving target. For compensating the above phase error, this proposed algorithm combines the undersampling discrete-time fractional Fourier transform (DFRFT) with the Doppler centroid ambiguity estimation to obtain the radial velocity. Before the above process, this paper applies the displace phase center antenna (DPCA) to suppress the clutter for detecting the moving target. After the process of compensating the phase error, the reconstructed azimuth signal is focused unambiguously by the traditional azimuth focusing approach. By the experiments and performance analysis, the validity of the proposed algorithm is demonstrated.