Research On Airborne Radar Clutter Suppression Method In Complex Environment

The airborne radar moves at the high speed in the air,with good maneuverability and a broad reconnaissance field of vision.However,the moving state of the carrier aircraft also makes the ground clutter have a relative speed,and the slow moving target is easily covered by strong clutter,which seriously affects the normal work of the radar platform.Therefore,clutter suppression has become the key task of airborne radar moving target detection.As the environment of the modern battlefield becomes more complex,the clutter suppression of airborne radar becomes more difficult.On the one hand,due to the influence of nonpositive lateral arrays,irregular array distribution and other factors of the radar platform itself,ground clutter produces serious distance non-stationarity.On the other hand,external environments such as topographic landform,target interference,and electromagnetic interference also exacerbates the non-uniformity of ground clutter.Therefore,how to effectively suppress airborne radar clutter in complex environments is the focus of this paper.Firstly,based on the accurate modeling of airborne radar clutter,this paper discusses the applicability of the Space-Time Adaptive Processing(STAP)method in airborne conformal array radar.Secondly,aiming at the non-stationarity of airborne radar clutter,the classical compensation method is studied,and the array element projection compensation method is proposed on this basis.Finally,aiming at the performance limitation of traditional STAP methods in non-uniform environments,a deep neural network based on low-rank,sparse and noisy prior information is proposed for clutter suppression.The main contents of the paper are summarized as follows:1.The modeling method of airborne radar clutter and the variation of clutter characteristics under non-ideal factors are elaborated.The planar array model and the conformal array model of airborne radar are introduced,and the theoretical derivation of airborne planar array radar clutter modeling and the clutter modeling of fissure radar is given.The clutter characteristics under non-ideal factors,including clutter power spectrum and clutter nonstationary characteristics,are analyzed by simulation.2.The applicability of the STAP method and the non-stationary compensation algorithm in the clutter suppression of airborne conformal array radar is discussed.The basic principles of several classical STAP methods are introduced,and the performance of STAP methods in the clutter suppression of airborne conformal array radar is analyzed by simulation.Aiming at the severe stationarity of short-range clutter,this paper proposes a matrix projection compensation method,which projects a three-dimensional array to a two-dimensional plane,and then compensates the projection array with an airspace dimension and a Doppler dimension.Simulation experiments verify that the method can effectively improve STAP performance.3.The method of airborne radar clutter suppression in non-uniform environment is studied.The basic principles of several classic non-uniform detectors are introduced,and the detection ability of detectors to identify interference targets in non-uniform environments is analyzed through simulation.Aiming at the fact that the non-uniform detector cannot effectively identify the interference target in the environment of low signal and noise ratio,resulting in the problem of target matching by the STAP method,this paper proposes a deep neural network low rank,sparse and noise prior information in radar echoes,which can be extended to the low-rank sparse decomposition model in the STAP field by solving the solution to achieve clutter suppression and target detection.Simulation experiments compare the clutter suppression performance of the proposed network with the classical decomposition model solution method and the STAP method,and verify the effectiveness of the proposed network.