Equivalent centroid-based method for velocity and position estimation of weak defocused maritime target
Siyu Xu, Bing Swen Sun, Yuming Jiang, Haochuan Wang, Yaowei Kang · IET conference proceedings. · 2024
To position and track ships on the sea, conducting synthetic aperture radar (SAR) imaging of moving vessels and analyzing their speed and position parameters is necessary. However, due to the target's movement, SAR images will suffer from defocus blur and position shift. This paper explores the characteristics of target defocus blur and proposes a method to replace inaccurate imaging positions with equivalent centroids. To further obtain the speed and position parameters of the target, a target parameter estimation method based on the equivalent centroid is proposed. First, continuous imaging in the azimuth direction is performed, and multiple range-Doppler (R-D) equations are established by obtaining the imaging centroid position of the target. Then, the velocity parameters are estimated based on the Doppler shift of the target and then the target's Positional parameters. The simulation results verify the effectiveness of the method proposed in this article.