A target detection algorithm of HFSWR basedonredundant discrete wavelet transform

In order to accurately detect the small moving targets in complex range Doppler (RD)images generated from the received signal of high frequency surface wave radar (HFSWR), a point target detection algorithm of RD images based on redundant discrete wavelet transform (RDWT) is presented. Firstly, according to the feature differences among point targets, sea clutter, ionospheric clutter, etc, the sea clutter and ground clutter regions in a RD image are firstly removed based on adaptive RDWT in range direction, and then the ionospheric clutter regions are removed based on adaptive RDWT in Doppler frequency direction. Secondly, the background noise components are suppressed by using gray image morphology operation. Finally, the point targets are extracted by an adaptive thresholding segmentation process. The experimental results show that the proposed algorithm can effectively suppress sea clutter, and ionospheric clutter, and background noise in a RD image, and can extract and detect the point targets in a complex RD images effectively, and its detection rate is superior to that of the improved constant false-alarm rate (CFAR) algorithm.