Accurate Direction Finding for Shipborne HFSWR Through Platform Motion Compensation
Cheng Wang, Ling Zhang, Jiong Niu, Gangsheng Li, Q. M. Jonathan Wu
Abstract
Shipborne high-frequency surface wave radar (HFSWR) plays a crucial role in ship target detection due to its mobility and flexibility in marine surveillance. However, accurate direction finding (DF) of shipborne HFSWR targets is extremely challenging due to the complex marine environment, which causes the platform to oscillate on six degrees of freedom (6-DOF) in addition to its forward motion, affecting the DF of the target. To solve this problem, we propose a motion compensation direction finding (MC-DF) method for shipborne HFSWR. In this paper, we model the motion of the platform and analyze the impact of the 6-DOF oscillation motion and forward motion on the target azimuth. We derive the steering vector of the radar array after motion compensation and use digital beamforming to accurately conduct DF of the target. The parameters required for motion compensation are provided by the inertial navigation system on the platform. The effectiveness of this method was verified through in-situ experiments on shipborne HFSWR.