Target Bearing Estimation Method for Range-Doppler-Only HFSWR Under Linear Platform Motion

The range-Doppler (RD)-only high-frequency surface wave radar utilizes multiple RD measurements to achieve target detection, significantly enhancing the flexibility and angle estimation accuracy of the radar system. When the receiver is mounted on a mobile platform, the flexibility of the radar system can be further improved; however, the motion of the receiving platform induces an additional Doppler shift, necessitating reconsideration of the target detection method. This article proposes a target bearing estimation method for RD-only high-frequency surface wave radar under linear motion conditions. First, the initial target bearing estimation is derived through cross localization. Subsequently, a generalized S-transform-based time-frequency analysis technique is employed to separate the composite received signals, enabling the extraction of interested target signals in the time domain. Finally, a virtual aperture technology is utilized based on the platform motion, thereby facilitating the refined target receiving angle estimation through digital beamforming processing. Simulation results validate the effectiveness of the proposed method.