Clutter Suppression And True-false Target Discrimination

The main function of radar is to detect the target of interest in the space by electromagnetic wave.However,a variety of natural environments,such as land and sea,will also scatter the electromagnetic wave and generate clutters with strong energy.When the clutter and target echoes enter the receiver at the same time,the target signal is likely to be covered by clutter,which will have a serious impact on signal processing,moreover the detected plots of remaining clutter residues will influence the subsequent target tracking.Therefore,clutter suppression has become a key technology in radar signal processing and data processing.Firstly,this thesis introduces the clutter characteristics.Then two important clutter suppression techniques are discussed: moving target indication(MTI)and moving target detection(MTD).The thesis introduces some kinds of MTI filters,which of pulse cancellation is mainly used to eliminate fixed ground clutter.Adaptive MTI filters designed by feature vector method and zero allocation method can be used to eliminate moving clutter.Moreover,in order to overcome the shortages of MTI filters,we give the ideas and methods in MTD filter-banks design.The FFT filter-banks can distinguish the target and clutter in frequency domain and improve the performance in moving target detection.The MTD filter-banks based on FIR not only can eliminate clutter effectively,but also can achieve coherent integration of target echoes.In addition,simulation and experimental data processing results prove that the MTI and MTD filters discussed in the thesis can achieve a good performance in clutter suppression.In practice,since clutter can not be suppressed completely by filters,the clutter residues will form false plots,which has a serious impact on true target tracking.In order to suppress the false plots,the thesis mainly studies from the perspective of plot discrimination.Firstly,according to the difference of target and clutter echoes,some efficient features can be extracted.Then the K-Nearest Neighbor algorithm will be applied to discriminate true and false targets.Finally,experimental data processing results show that the proposed method can obtain a good classification performance,which further can achieve the purpose of suppressing the clutter residues.