Improved main-lobe cancellation method for space spread clutter suppression in HFSSWR

In HF hybrid sky-surface wave radar (HFSSWR), the performance of detecting low velocity target will be greatly affected by space spread clutter (SSC), such as the broadening first-order sea clutter and the ionospheric clutter. Main-lobe cancellation is a powerful method for SSC suppression which using the strong spatial correlation to obtain a target-free training data. But due to the non-stationary properties of ionosphere, the clutter statistics change significantly among training data. In order to get training data which contains precise clutter information, an improved main-lobe cancellation (IMLC) method based on single notch space filter and correlation analysis is proposed. Firstly, a main-lobe clutter canceller based on single notch space filter has been developed to block the target component. Then, an optimized correlation analysis strategy (OCA) is presented to choose the efficient training data. Finally, the method is examined by measured data and the results indicate the method has a good performance for SSC suppression than traditional method.