Research On Long-term Coherent Integration Algorithms Of Radar

In order to improve the detection ability of the target during the detection of the weak target by the radar,the time for the radar to illuminate the target will be increased.This increases the number of echoes and enhances the signal-to-noise ratio of the echo signal.However,the increase in the target irradiation time also brings about the problems of moving across the range unit and across the doppler unit,especially when the speed of the target is very high and the maneuverability is strong.How to solve the problem of Across range unit and Across Doppler unit caused by high-speed and high-maneuvering targets under the long-term integration of radar,and the completion of target detection has become a research hotspot.This thesis conducts research from the following aspects:1.The basic knowledge of radar detection was introduced on this basis.The problems of cross-range unit and cross-doppler unit were explained and the causes and conditions of these two problems were analyzed.The simulation shows the influence of range movement and Doppler unit movement on traditional radar moving target detection.Afterwards,it analyzes the Radon-Fourier transform algorithm for uniform speed target de-tection and the Radon-Lv' s Distribution algorithm for target detection with second-order motion parameters.The principles and implementation steps of these two algorithms are studied.Finally,their feasibility is verified by computer simulation.2.A third-order moving target coherent integration algorithm based on Frequency spectrum reversing was proposed.First,the motion model of the third-order moving target is established and the mathematical expression of the echo is derived,and then the mathematical expression of the two-dimensional frequency spectrum of the third-order moving target is derived based on the series inversion.The two-dimensional spectrum of the echo signal is folded symmetrically along the Doppler frequency dimension,and the symmetrical signal is conjugate multiplied with the original expression signal.Then construct a matching function to match the data after the symmetric conjugate operation to complete the detection and parameter estimation of the moving target.The specific implementation of this method and the accumulation and comparison of other algorithms are shown through computer simulation,and the detection probability and computational complexity are also analyzed.3.A fourth-order moving target coherent accumulation algorithm based on the search and compensation of the Zero-Trap Line was proposed.According to the influence of the target motion speed on the spectrum expression,the algorithm completes target detection by searching for a zero trap line related to the speed.After obtaining the speed information,a parameter search compensation function is constructed to estimate the remaining parameters.The two-dimensional spectrum expression of the fourth-order moving target echo is deduced.Based on the characteristics of the spectrum expression,the detection algorithm and the parameter estimation principle of the trap zero line extraction are described.Finally,the detection probability and computational complexity of the algorithm are analyzed,and the feasibility of the algorithm is verified by computer simulation.