DOA Estimation of Compact HFSWR by the Virtual Array Synthesis Algorithm

Direction-of-arrival (DOA) estimation using a small-aperture compact high-frequency surface wave radar (HFSWR) remains challenging due to its poor azimuth resolution. To solve this problem, a novel DOA estimation method is proposed by exploring virtual array synthesis in this paper. The principle of virtual array synthesis is put forward, which is based on the motion of the target relative radar. Then, the rearrangement of the received signals is executed by satisfying the conditions of the virtual array synthesis. Finally, array snapshots are formed by rearranged signals for DOA estimation. Additionally, considering that the target speed is unknown, the maximum peak sidelobe ratio (PSLR) criterion be used for the selection of optimal results. The numerical simulation verifies the effectiveness of the proposed method.