基于多通道补偿的毫米波雷达高速目标检测方法

High-speed target detection of millimeter wave radar based on multi-channels compensation

目标检测是雷达的重要任务之一,利用长时间信号积累能有效提高低信噪比时的检测性能.对于高速运动目标,脉间回波存在相位差,及严重的距离走动现象,影响相参积累的效果.针对雷达系统高速运动目标检测的问题,提出一种基于多通道补偿的方法,提高毫米波雷达脉间相参积累性能.该方法将目标速度范围划分成若干区间,对每一区间设置一个补偿通道,各通道按对应速度区间的中值对输入信号进行走动校正及相位补偿,补偿后经过匹配滤波器输出;选取所有通道输出值的最大值,与预先设定的阈值的判决器进行比较,以确定有无目标.该方法与恒虚警检测结合,无需预先估计目标速度.用Matlab构造毫米波雷达发射与接收回波的模型,对接收信号进行多通道补偿高速目标检测进行了仿真.仿真结果表明,在毫米波雷达高速目标检测中,多通道补偿方法能有效的检测出微弱高速运动目标,与直接相参积累方法相比,可提高7dB的信噪比,增强毫米波雷达系统的检测性能.

The target detection is an important task of radar systems.The detection performance of radar system can be improved by long-term signal integral when the signal to noise ratio（SNR）is low.However,with the development of aerospace technology,the target’s velocity becomes higher and higher.Also the target’s radar cross-section becomes smaller and smaller which results in SNR coming down.For the detection of high-speed targets,there would be serious echo range migration between the adjacent repeat intervals of the radar which will interference the method of coherent integration to improve the SNR.There would be coupling between frequency and the number of echo after the echo coherent integration.This coupling will give rise to the echo range migration in the time-domain when the target’s velocity is high.For the problem of high-speed target detection in radar system,this paper puts forward a new method based on multi-channels compensation.This method is aimed at diminishing the effect of the coupling and sets several channels to compensate velocity which reduces the coupling of the system in a certain channel.Therefore,the echo in the time-domain will have lower range migration or even no range migration.After＆amp;nbsp;speed compensation,the radar system compares the output of each channel,and transfers the maximum one of the output of the channel to the threshold detector which has the threshold value in advance.Then radar system estimates whether the target exits.The threshold value is chosen based on statistical property of Gaussian noise which meets the false detection probability when the input signal contains only Gaussian noise;the output signal should also have the characteristics of Gaussian noise.This method does not need to estimate the speed before targets detection and just need to determine the speed scope roughly.At the same time,the transmitting and receiving model of the millimeter wave radar is structured with the help of Matlab.Then the received signal is com-pensated through multi-channels.Theoretical and simulation results demonstrated that the method based on multi-channels compensation can effectively detect the high-speed targets and increase the SNR by 7 dB compared with the method based on coherent integration.So this method improves the detection performance.