Phase Errors Compensation Algorithm of Inverse Synthetic Aperture Ladar based on CS-Fmea

In view of the vibration and initial phase errors, the azimuth defocusing of the inverse synthetic aperture ladar is seriously affected and the imaging quality is poor. A phase compensation algorithm based on Circular Shifting-Fast Minimum Entropy Algorithm(CS-FMEA) is proposed. Firstly, based on the imaging geometry model of inverse synthetic aperture lidar (ISAL), the influence of phase error on the signal is analyzed, and the expression of phase error is given; Secondly, the phase compensation effect of the fast minimum entropy algorithm is analyzed. The problem of incomplete phase compensation is caused by the residual rotation phase of the algorithm. A method of circular shifting and windowing is proposed to eliminate the influence of rotation on the gate of the distance gate, and the concrete implementation steps of the algorithm are given. Finally, by comparing the simulation results, three indexes of image entropy, contrast and operation efficiency are used to prove that the algorithm can significantly improve the phase error compensation performance.