A Novel Video ISAR Imaging for Rotating Space Targets Based on Pulse Train Design

Limited to the radar pulse repetition frequency (PRF), the quality of inverse synthetic aperture radar (ISAR) image for space micro-motion targets is poor, when performed by the conventional Range-Doppler (R-D) algorithm. In this paper, a method aiming at the video ISAR imaging for rotating space targets based on R-D algorithm is proposed. By means of the prior information that the target is rotating, a set of transmitted pulse train are designed to increase the pulse number within the required imaging time, and so as to improve the ISAR image quality of the rotating target. Considering that the image quality is sensitive to the estimated frequency, a circular search for accuracy frequency is added in the processes. Besides, by extracting different sets of echoes and realizing the ISAR imaging at different angles, the video ISAR imaging can be achieved. The simulation results show that the estimated rotation frequency in the end is exact and the ISAR image is satisfactory, illustrating the effectiveness of the proposed method.