Research On Long Time Integration And Detection Algorithm For Weak Target In High Frequency Radar

Long-time coherent integration technology is one of the most important methods to improve the radar detection capability of weak maneuvering targets,and the effects of ARU and DFM may greatly affect the performance of long-time coherent integration.In order to solve the ARU problems of high-speed moving targets in HFSWR,this paper proposes a novel long-time coherent and detection algorithm based on radial and non-radial unified uniform motion model named accurate range model.Simulation experiments and measured data processing results show that under the condition of sacrificing part of the computational complexity,through the three-dimensional search of radial velocity,radial distance and true velocity,the proposed algorithm not only can achieve the effective measurement of the target's true velocity,but also has the highest signal-to-noise ratio gain and anti-noise performance.The work content of this paper is mainly divided into the following three parts according to the difference of the coherent integration algorithm.1.The long-time coherent integration and detection algorithm for high-frequency surface wave radar based on Keystone transform is studied.Firstly,the theory of correction to linear range walk with Keystone transform method and coherent integration based on KT is analyzed.Secondly,the effectiveness of Keystone transform and the performance of the coherent integration algorithm is verified by the simulation experiment.Finally the coherent integration method based on Keystone transform and target detection processing through CFAR are carried out on the measured data of the high frequency surface wave radar.2.The long-time coherent integration and detection algorithm for high frequency surface wave radar based on Radon transform is studied.Firstly,this paper theoretically analyzes how the algorithm realizes the process of coherent integration and parameter estimation through the two-dimensional joint search of radial distance and radial velocity.The simulation experiment verifies the effectiveness of the coherent integration of high-speed moving targets in the high-frequency surface wave radar system.Finally,the measured data processing results of the high-frequency surface wave radar is used to analyze the performance of RFT method in the actual environment.3.A novel coherent integration and detection algorithm for high frequency surface wave radar based on the accurate range model and the generalized Radon Fourier transform is proposed.According to the practical application scenarios of high-frequency surface wave radar,this paper proposes an accurate range model for the target with constant Cartesian velocities,and the echo signal of target with constant Cartesian velocities is established.Then a long-time coherent integration algorithm for high-frequency surface wave radar with speed measurement function is proposed.Simulation experiments and the measured data processing results show that the proposed method can effectively improves the integration performance of the target with high speed,and has achieved greater advantages in the performance of coherent integration,target detection and the anti-noise.