Study On Clutter Suppression Method Of Inhomogeneous Environment Based On Multistage Wiener Filter

Space-time adaptive signal processing techniques are widely used in biomedical engineering and other areas. Bioradar means the radar which can detect characteristics of life. It combines the principles of radar with biomedical engineering which has strong penetrability, and also can detect biological signal of life in the far distance. Phased array technology has been widely used in the field of radar, especially conformal phased array, which received much attention around the world for its the unique advantages such as wide scanning range and ease of integration.Unlike conventional planar phased array radar, conformal array radar clutter often emerged certain non-homogeneity in different directions, This non-homogeneity leads to increased error of clutter covariance matrix obtained by estimation, so performance of the conventional space-time adaptive signal processing algorithm is severely degraded.The main purpose of this study is to develop a new adaptive processing algorithms in order to suppress non-homogeneity clutter conformal phased array faced with in the case of considering engineering implementation, and to this end, we conducted the following work:Firstly, we establish a handpiece conformal array clutter mathematical model as an example.Based on simulation and the characteristic analysis of conformal array radar clutter, we proposed spatial filter in elevation to overcome the non-homogeneity of the clutter, meanwhile, in order to further improve the noise suppression performance, we subsequently cascade an improved covariance matrix taper algorithm to correct the clutter covariance matrix obtained by estimation. Covariance matrix inversion is the largest part of the operation of space-time adaptive processing algorithms. In order to reduce the amount of computation, we use multistage wiener filter based on correlation subtraction structure in place of covariance matrix inversion to get adaptive filter weights for clutter suppression.Finally, we construct a novel algorithm of suppressing clutter of airborne conformal array radar, named spatial filter in elevation- based covariance matrix taper multistage wiener filter algorithm(ENCMT-MSWF).In order to verify the correctness, effectiveness and versatility of the algorithm, we conducted a simulation of millimeter wave, meter wave, decimeter wave and other different operating wavelengths, and of conformal array under different structures for the clutter suppression performance of the algorithm. Finally, we made a comparative analysis and simulation of the proposed algorithm and existing algorithm for the amount of computing. Simulation results showed that the proposed method has better performance in suppression of conformal array radar clutter than other existing methods and has the advantages of small amount of computation and fast convergence speed. It is easy to be implied in engineering and has practical application prospects in conformal array radar clutter suppression.