Study on Spaceborne Multi-channel SAR Moving Target Positioning Technology

The doppler frequency generated by the target's radial moving will cause its azimuth position in the SAR image to deviate from the true position. In order to obtain the true position of the target, it needs to be relocated. However, when the PRF of a multi-channel system is smaller than the doppler bandwidth, directly using traditional methods will cause spectrum aliasing. This paper proposed a multi-channel spaceborne SAR moving target positioning algorithm combined with spectrum reconstruction algorithm. This method improves the positioning width and expands the application range of traditional methods. In addition, this paper also gave an analysis on the impact of SCNR on positioning accuracy, and the requirement of SCNR can be calculated back through the expected positioning error boundary. Finally, the algorithm was verified by simulation data.