A motion error compensation method for linear array three-dimensional synthetic aperture radar

In the last decade, an increased interest has been devoted to linear array 3-D synthetic aperture radar(LA-3D-SAR) in radar field. Compared with the traditional 2-D SAR, the motion error of LA-3D-SAR is more various and can result in serious defocusing phenomenon. It is difficult to compensate these errors respectively. For this problem, a 3-D autofocus backprojection(BP) algorithm based on phase error estimation is proposed. The motion error can be modeled as the phase error in range compression domain. Therefore, the method uses the estimated phase value obtained by the coordinate descent method to compensate various motion errors. The sharpness value of 3-D image is treated as the objective function of the coordinate descent method. The simulation results show that the proposed method can obtain the wellfocused 3-D image and the focusing effect is close to the error-free imaging result basically. And processing of experimental data demonstrates the efficacy of this method.