A Method of ISAR Imaging for Low-Altitude Target

In processing of ISAR imaging for low-altitude target, due to the echo of target is covered by clutter, it is impossible to get ISAR image directly. In this paper, a method is proposed for low-altitude target. Firstly, all echoes of full aperture are divided into a number of sub-aperture with sliding window. In each sub-aperture, the clutter is suppressed by constructing adaptive filters. To compensate the errors caused by moving of target, the number of wrapped period is established through keystone algorithm by searching based on minimization of high range resolution profile entropy. Then, the signal of target is collected from sub-aperture to the set of ISAR echoes. The ISAR image of low-altitude target is obtained by ISAR imaging of collected echoes. Finally, the method is evaluated by the result of simulation.