Research Of Signal Processing And Target Angle Measurement On The Missile Phased Array Radar

With the emergence of high-performance stealth fighters,low-altitude defense penetration,electromagnetic interference or other newly-developing technologies and equipments or strategic tactics,the battlefield electromagnetic environment becomes increasingly complex and the precise-guidance technology is facing with severe challenges.With an eye to such advantages of anti-jamming performance,detecting and tracking numbers of targets,reliability and flexible beam pointing and so on by the phased-array radar,the use of phased-array technology to improve the precise-guidance performance becomes a hot topic.This thesis takes missile-borne phased-array radar as the research object,presenting the flow of signal processing of missile-borne phased-array radar on the basis of the array signal model which based on sub-matrix division,analyzing the clutter model and its characteristics of missile-borne phased-array radar,focusing on the research of target angle measurement technology under the background of interference and clutter.The main contents are as follows :1,Aiming at the irregular rectangular array,an array signal model based on submatrix partitioning is established.The signal processing flow of such missile-borne phased-array radar is analyzed and explained,including digital beam forming,matched filtering,moving target detection,space-time adaptive processing and target angle measurement.2,Aiming at a typical array structure of such missile-borne phased-array radar,the angle measurement principle by conventional sum-difference beam forming is deduced.By the simulation of sum-difference beam directional diagrams and guiding angle surfaces by the monopulse,the linear relationship between the surfaces above and azimuth or elevation angle is verified.3,Aiming at the target angle measurement in the background of disturbance,a method of constructing airspace adaptive sum-difference beam is proposed based on the nine-point constraint;The method takes the conventional sum-difference beam guiding angle surface as a reference,improving the distortion of the MVDR weights sumdifference beam by adjusting sum-difference angle surface of the current beam pointing and other 8 adjacent targets in airspace channels,and constructing the adaptive sum-difference beam.The simulation results show that the algorithm can effectively solve the problem to measure the angle of target precisely in the background of main lobe or side lobe interference which the conventional method can't resolve.Then the signal processing of adaptive monopulse sum-difference beam is presented on the basis,discussing influences of grating nulls,disturbance directions,array amplitude and phase errors or other factors on the performance of adaptive sum-difference beam monopulse angle measurement,and carrying out the simulation above.4,Analyzing clutter models and characteristics of such missile-borne phased-array radar.Aiming at the measurement of target angle in the background of clutters,and considering operands and complexities of STAP angle measurement algorithm,the reduced dimension STAP algorithm(JDL,3DT)is proposed to solve this problem on the basis of the adaptive sum-difference beam monopulse angle measurement algorithm by the airspace only.Finally,a comprehensive simulation of adaptive sum-difference beam angle measurement is carried out for different application scenarios,different kinds of interference or clutter backgrounds and other non-ideal factors,and the measurement results are discussed.