Broadened Sea Clutter Suppression Method for Shipborne HF Hybrid Sky-Surface Wave Radar

Abstract

In shipborne high frequency (HF) hybrid sky-surface wave radar, the sea clutter is the important component of the echoes and the major clutter background for vessel target detection. However, due to the complex radio paths, the sea clutter spectrum spread severely and exhibit a complex signature. In this paper, a space-time adaptive processing (STAP) based on the Gabor wavelet filter to extract the sea clutter space-time distribution is proposed to suppress the broadened sea clutter. The proposed method involves three steps. First, the two-dimensional Gabor wavelet transform is applied to the Angle-Doppler(AD) spectrum to extract the sea clutter component by using the adaptive threshold method. Second, the remaining component besides the sea clutter in the extracted results is eliminated by using the template convolution and connected component labeling method. Third, the clutter covariance matrix is estimated based on the segmentation region of the sea clutter. According to the experimental results, the proposed method can obtain a more accurate estimation of the broadened sea clutter space-time distribution and achieve better suppression performance.