Research On Ground-Based Radar High-Speed Target Detection Technology

With the development of high-speed aircraft,high-speed target detection has become one of the hot topics in the radar field.Due to the high-speed motion of the target,the parameters do not match in the traditional accumulation process,so that the echo signal moves across the distance unit,across the Doppler unit,and across the beam unit during the coherent accumulation process,and the signal energy cannot be effectively accumulated.,which reduces the detection probability of high-speed targets.In this thesis,the high-speed target coherent accumulation algorithm is studied for the "three-cross " problem in the high-speed target detection process of ground-based radar.The main content includes the following parts:In the first part,the high-speed target motion models are established,and the echo characteristics under different motion patterns are studied.The distance tracking correction performance of Keystone algorithm,envelope interpolation shift algorithm and adjacent cross-correlation(ACCF)algorithm are analyzed and compared.The first two algorithms are superior in detection performance,and ACCF is superior in computational complexity.The coherent accumulation characteristics of RFT algorithm,FRFT algorithm and Dechirp algorithm are studied.RFT algorithm can correct distance and Doppler walking simultaneously,but has higher blind speed side lobes,which is not conducive to detection.FRFT algorithm can achieve target matching accumulation.However,the implementation is complicated,and the Dechirp algorithm is simple to implement,but the parameter exhaustive search is required,and the amount of calculation is large.In the second part,referring to the ACCF algorithm,a high-speed target detection method based on pulse frequency domain reverse multiplication is proposed.Aiming at different motion models,combined with slow time dimension accumulation algorithm,a RM-based uniform high-speed target detection algorithm is proposed and RM-SKTFRFT-based uniform acceleration high-speed and variable acceleration high-speed target detection methods are proposed.Combined with theoretical analysis and simulation verification,it is proved that the RM algorithm can effectively solve the problem of the initial distance information loss of the ACCF algorithm in the distance walking correction process.In the third part,a high-speed target detection method based on TBD is proposed.The second-order Kalman filter is used for pre-detection tracking.The next frame data motion parameter estimation is performed in a single track,and the high-speed target parameter search process is transformed into a track search process,which reduces the computational complexity of the traditional algorithm parameter search and achieves the coherent accumulation of high-speed targets.In the fourth part,the high-speed target detection method under the ubiquitous radar system is given aiming at the high-speed target cross-beam motion problem.The CPI constraint condition of the ubiquitous radar is proposed.The cross-beam accumulation method of the ubiquitous radar is studied and the high-speed target is derived.Specific amplitude and difference angle theoretical values,which solves the problem of angle change in high-speed target cross-beam motion and specific amplitude angle measurement.