Preliminary research on target detection in first-order peaks with adaptive cancellation

HFSW radar can detect oceanographic parameters based on electromagnetic waves diffracting along the sea surface. A difficulty arises in detecting slowly-moving targets because of the strong ocean clutter. For wide-beam HF radar, broadened first-order peaks complicate target detection further, so no effective detection algorithm in first-order peaks has yet been put forward. The paper examines the Bragg peaks of wide-beam HF radar. The reason why the first-order Bragg peaks are broadened is analyzed, and then the conclusion that the two first-order peaks from a distant sea cell with unitary current are profile-correlative is drawn. Based on the conclusion, a new method is presented for target detection in first-order peaks. The method performs well both on simulated data and on real data with the HF system OSMAR2000.