摘要
线性调频连续波(LFMCW)雷达是探测近程低小慢目标的常用传感器。本文针对LFMCW雷达,基于距离维和速度维的二维傅里叶变换(2D-FFT)技术,研究了密集地物杂波条件下其对低小慢目标的检测性能。首先对LFMCW雷达的差频信号进行了时域和频域分析,研究了影响目标检测性能的关键因素;其次研究了临近地物杂波对目标测速、测距的影响机理;最后进行了典型场景多次蒙特卡罗(Monte-Carlo)仿真,研究了雷达相关参数(调频率、带宽、是否MTI等)、目标相关参数(速度、RCS等)和杂波相关参数(强度、谱宽等)对于检测性能的影响机理。研究表明,对于强杂波背景下的低小慢目标检测,速度维的检测至关重要,雷达宜采用大带宽、长时间积累技术,才能有效区分杂波和目标,保证目标顺利检测。
Linear frequency modulation continuous wave (LFMCW) radar is an effective sensor for detecting the performance of low-small-slow target (LSS-Target) in the presence of dense architectural clutter,wherein the two-dimensional Fast Fourier transform (2D-FFT) is employed. Firstly,the time and frequency domains of beat frequency signal are analyzed.Secondly,extended to the ground clutter scenario,the influence mechanism of clutter on range and velocity measurements of LSS-Target is analyzed. Finally,by using multiple Monte-Carlo simulations,the comparison of radar parameters (frequency modulation ratio,bandwidth,moving target indication or not etc.),target parameters (RCS,velocity etc.),and clutter parameters (amplitude,spectral width etc.) On detection performance are analyzed. The study shows that the detection in velocity dimension is crucial to discriminate LSS-Target. Meanwhile,it is better to use large bandwidth signal and long-time accumulation technology to improve the target detection performance on strong clutter background.
引文
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