Research On Long-time Integration Algorithm For Radar Weak Target

Radar weak target’s long-time integration technique is one of the researchhotspots in radar signal processing in recent years, it can improve the signal-to-noiseratio and signal-to-clutter ratio of the weak targets effectively, so as to improve thedetection performance of surveillance radar. With the increase of integration time, thetarget may migrate across different radar range cells and different radar Doppler cellsand even different echo beam during the integration period. This paper makes furtherstudy on radar weak target’s range migration and Doppler migration, and puts forwardthe corresponding distance compensation algorithm and velocity compensationalgorithm, the main research works and achievements show as follows:(1) According to the problem of radar weak target’s long-time integrationmay produce range migration and Doppler migration, this paper takeslinear frequency modulated signal as an example, makes future studyon the mechanism of the range migration and Doppler migration. Thispaper analysis the mechanism of radar weak target’s range migrationfrom time domain and frequency domain, and gives the mechanism ofDoppler migration under two situations. Simulation result shows thatrange migration and Doppler migration exist in the long-time pulseintegration.(2) According to the problem of the traditional Keystone transformmethod’s low efficiency when compensating the range migration of theapproximate radial moving target, this paper proposes a rangemigration compensation algorithm based on improved Keystonetransform. It can correct range migration caused by the radial velocityof the moving target before coherent integration. Simulation resultshows that the proposed algorithm can correct range migrationefficiently and improve coherent integration capability.(3) According to the problem of the high resolution range profile (HRRP)of the signal may produce range migration and Doppler migrationcaused by the target velocity, a velocity compensation algorithm basedon up-and-down frequency measuring method is presented in this paper.Simulation results show that the up-and-down frequency measuringspeed compensation algorithm can correct the echo signal’s range migration effectively, the amount of calculation is small, and theefficiency of the algorithm is high.