Research On Non-Uniform Clutter Suppression Method Of Radar Based On Space-Time Adaptive Processing Technology

Array signal processing is an important branch of modern signal processing. It is now widely used in many fields, such as biomedical engineering, biomedical science, radar and so on. Array signal processing is applied mainly in complex background such as strong clutter and interference.If the platform where processer is located is in the air and kinetic, it has to face with the problem of clutter spectrum broadening due to the platform’s movement. As a key technology of solving the problem above, the optimal processor of space-time adaptive signal processing(STAP) can perfectly suppress the clutter and jamming to achieve the goal of target detection throught a space-time two-dimensional joint adaptive processing filter in thoery. However, due to the limitations of the complexity of the actual working environment, the the level of technology, and its own high need for computation, the optimal processor cannot be achieved in reality.Based on the need of engineering background, the main work of this paper is following:1. Based on the backgroud of cylindrical and parabolic conformal arrays, the placement laws of array elements for parabolic conformal array were analyzed and an effective way of subarray division to realize the antenna pattern synthesis of conformal array was proposed. On the basis, we established the mathematical model of clutter echo of airborne parabolic conformal phased array radar, and then we compared and analyzed the structure characteristics and the distribution features of the radar clutter of different conformal arrays. The simulation results showed that clutter of airborne parabolic conformal phased array radar has the characteristics that main lobe of orientation is seriously broadened, its power spectrum presents strong heterogeneity and clutter has high degrees of freedom, etc. This part of the work has laid an important foundation on the further research of the method of clutter suppression.2. Based on the characteristic analysis of conformal array radar clutter, we proposed spatial filter in compensation to overcome the non-homogeneity of the clutter, and finally construct a novel algorithm which combined the algorithm of covariance matrix taper to improve the algorithm of registration based compensation. Simulation results showed that the proposed method has better performance in suppression of conformal array radar clutter than other existing methods, and is more stable compared to other methods. Also it has practical application prospects in conformal array radar clutter suppression.