Study On Echo Simulation And Adaptive Clutter Suppression Of Airborne Phased Array Radar

In the process of research and development of new system radar,radar echo simulator with low cost,high reliability and flexibility has attracted wide attention,and its importance in the process of research and development is becoming more and more prominent.Airborne phased array radar is one of the research hotspots of current system radar.The development period of it can be shortened greatly by using radar simulator technology reasonably.In fact,in order to adapt to different simulation scenarios and radar systems,the existing radar simulators are not very versatile.Based on the actual demand of the research project,this thesis carries out the research work of airborne phased array radar echo simulation,and designs and implements the echo simulation system in the scenario required by this project.At the same time,aiming at the problem that airborne radar is affected by strong ground clutter and the performance of target detection is decreased,the relevant research and simulation of adaptive clutter suppression are carried out.The main research content includes the following four parts:1.The theoretical research on radar echo simulation and clutter suppression is carried out.This thesis introduces the phased array radar system,space-time adaptive processing algorithm and the principle of two clutter compensation algorithms.2.An airborne phased array radar echo simulation system is designed and implemented,and its correctness is verified by means of radar signal processing.After the overall design scheme of the simulation system is given,the function of each submodule and the design and implementation of user interface are realized,including antenna,wave position,target motion trajectory,ground clutter,cloud clutter and other modules.In order to realize the analog output function of echo signal,a semi-physical DA-AD conversion system is built by using PCI9102 and PCIe8504 data acquisition cards.In order to enrich the types of target trajectory modeling,an instantaneous velocity vector modeling method based on the tangent vector of existing curves is proposed.This method is more suitable for complex target motion modeling than the traditional method.3.The unified model of clutter sequence generation is modeled and simulated.Three kinds of power spectrum and four kinds of amplitude spectrum distributions are analyzed and simulated in the clutter statistical modeling method.Aiming at the problem that traditional clutter modeling methods are difficult to unify,a Multi-Branch GAN network model is proposed,which completes the network construction,training and result verification.Other distribution models are introduced to verify the universality and expansibility of the network.4.Research on iterative weighting algorithm for preprocessing based on generalized inner product.The two main factors of clutter non-uniformity are analyzed.In order to solve the problem of non-stationarity of clutter distance caused by the non-forward-sidelooking array,Doppler Warping and Angle Doppler Compensation algorithms are used to compensate the problem.The effectiveness,advantages and disadvantages of the algorithm are discussed by using improvement factor.Aiming at the problem of nonuniformity in clutter environment,the traditional generalized inner product algorithm is simulated.In order to solve the shielding effect of traditional algorithms in multiinterference scenarios,a preprocessing iterative weighting algorithm based on generalized inner product is proposed.Compared with traditional algorithms and existing iterative algorithms,it has a faster convergence rate and a smaller amount of computation while maintaining similar or better performance output.