Research On Long Time Integration Algorithm For Radar Signal

In the radar detection process,in order to improve the detection of the weak target,usually use long time integration method to improve the echo signal-to-noise ratio(SNR).However,due to the maneuvering characteristics of the target,range migration(RM)and Doppler frequency migration(DFM)problems will occur,thus invalidating the performance of the traditional integration method.Therefore,how to solve the RM and DFM of moving target in the long time integration to detect weak target is particularly important.In view of the problems above,this paper studies the echo models of three different maneuvering targets and proposes corresponding long time integration algorithms for different echo models.The specific work of this thesis are as follows:(1)For the moving target with even speed,the target echo will have serious RM during the high-speed moving process.In this paper,two long time integration algorithms of KTR and KTP are proposed to solve the RM of the target echo.This two algorithms realizes to slove the Doppler ambiguity number in frequency domain and time domain.Simulation experiments show that both algorithms can effectively eliminate the RM of the target echo and achieve energy accumulation.Compared with the GKT algorithm,the KTP algorithm has better detection performance in low SNR environments,the KTR algorithm's computational complexity is greatly reduced.(2)For the moving target with acceleration,the target echo will have RM during high-speed moving process.In addition,the target's radial acceleration will also cause DFM.When the radar range resolution is not high,the range curve caused by radial acceleration can be ignored.For this case,a long-time integration algorithm based on Keystone transform and SPF is proposed.Compared with the second-order RFT algorithm,the proposed algorithm can get accurate estimated values with less computation complexity.In view of the fact that range curve can't be ignored,a long-time accumulation algorithm based on SKT and STR is proposed.This algorithm can achieve effective accumulation of target echo energy under different speed and acceleration conditions.Compared with SKTRFT algorithm,it does not have blind speed side lobes.(3)For the accelerating moving targets,the target has the acceleration and the jerk,a long time integration algorithm based on KTR and PCPF is proposed.Firstly,the RM of the target echo is corrected by the Keystone transform and the Radon transform.Then the Product Cubic Phase Function is used to estimate the acceleration and the jerk of the target and compensate the high-order phase of the echo,so the DFM is corrected,and finally through the Fourier transform in the slow time domain for energy accumulation.Compared with KTCPF algorithm and GKTGDP algorithm,the computational complexity is reduced.