南京大学学报(哲学·人文科学·社会科学)
南京大學學報(哲學·人文科學·社會科學)
남경대학학보(철학·인문과학·사회과학)
JOURNAL OF NANJING UNIVERSITY(PHILOSOPHY,HUMANITIES AND SOCIAL SCIENCES)
2014年
3期
356-360
,共5页
戴作宁%张兴敢%唐岚%柏业超
戴作寧%張興敢%唐嵐%柏業超
대작저%장흥감%당람%백업초
信号检测%高速目标%毫米波雷达%相参积累
信號檢測%高速目標%毫米波雷達%相參積纍
신호검측%고속목표%호미파뢰체%상삼적루
signal detection%high-speed targets%millimeter wave radar%coherent integration
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7 dB的信噪比,增强毫米波雷达系统的检测性能。
目標檢測是雷達的重要任務之一,利用長時間信號積纍能有效提高低信譟比時的檢測性能。對于高速運動目標,脈間迴波存在相位差,及嚴重的距離走動現象,影響相參積纍的效果。針對雷達繫統高速運動目標檢測的問題,提齣一種基于多通道補償的方法,提高毫米波雷達脈間相參積纍性能。該方法將目標速度範圍劃分成若榦區間,對每一區間設置一箇補償通道,各通道按對應速度區間的中值對輸入信號進行走動校正及相位補償,補償後經過匹配濾波器輸齣;選取所有通道輸齣值的最大值,與預先設定的閾值的判決器進行比較,以確定有無目標。該方法與恆虛警檢測結閤,無需預先估計目標速度。用 Matlab 構造毫米波雷達髮射與接收迴波的模型,對接收信號進行多通道補償高速目標檢測進行瞭倣真。倣真結果錶明,在毫米波雷達高速目標檢測中,多通道補償方法能有效的檢測齣微弱高速運動目標,與直接相參積纍方法相比,可提高7 dB的信譟比,增彊毫米波雷達繫統的檢測性能。
목표검측시뢰체적중요임무지일,이용장시간신호적루능유효제고저신조비시적검측성능。대우고속운동목표,맥간회파존재상위차,급엄중적거리주동현상,영향상삼적루적효과。침대뢰체계통고속운동목표검측적문제,제출일충기우다통도보상적방법,제고호미파뢰체맥간상삼적루성능。해방법장목표속도범위화분성약간구간,대매일구간설치일개보상통도,각통도안대응속도구간적중치대수입신호진행주동교정급상위보상,보상후경과필배려파기수출;선취소유통도수출치적최대치,여예선설정적역치적판결기진행비교,이학정유무목표。해방법여항허경검측결합,무수예선고계목표속도。용 Matlab 구조호미파뢰체발사여접수회파적모형,대접수신호진행다통도보상고속목표검측진행료방진。방진결과표명,재호미파뢰체고속목표검측중,다통도보상방법능유효적검측출미약고속운동목표,여직접상삼적루방법상비,가제고7 dB적신조비,증강호미파뢰체계통적검측성능。
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 <br> 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.