The Characteristic Analysis And Suppression Method Research Of Sea Clutter For The Shore-based Warning Radar

Because of the backscattering effect of the sea surface on the radar electromagnetic wave,the radar echo signal contains a lot of sea clutter,which affects the detection and tracking the performance of the maritime radar.To suppress sea clutter and improve the detection capability of the radar in sea clutter background,this paper mainly studies on the characteristics and suppression methods of sea clutter based on the real data collected from a shore-based warning radar.The main work is summarized as follows:First,based on the radar echo data,the peculiarities of sea clutter are analyzed.It is verified that the K distribution has a better property of fitting by fitting the amplitude distribution of the real sea clutter data.Moreover,by estimating the power spectrum of the real data,it is found that sea clutter has multispectral peak and large spectral width.Also,by studying the correlation of sea clutter data,it is found that there is a big difference between sea clutter and target in Doppler correlation.Second,singular value decomposition(SVD)method and the traditional adaptive frequency filtering method are both used to deal with the real sea clutter.It is found that the SVD method is only suitable for the suppression of strong sea clutter in high sea conditions,while for the suppression of weak sea clutter or the detection of independent targets,it is also easy to remove the target signal while suppressing sea clutter.Moreover,the reason why the sea clutter cannot be suppressed effectively by adaptive frequency filtering method is also explained.Third,according to the great difference between sea clutter and target in Doppler correlation,a new algorithm for sea clutter suppression based on two-stage Doppler correlation discrimination is proposed.The two-dimensional doppler frequency matrix obtained by the estimation of frequency measurement is used to distinguish the sea clutter from the moving target by two-stage correlation discrimination between pulse and region successively,and then the clutter is normalized to the average noise level to realize the suppression of sea clutter.The validity of the method is verified by plenty of real sea clutter data.