调频连续波激光雷达高速目标测量误差的校正方法  

Error Correction Method in Measurement of High-Speed Targets with Frequency-Modulated Continuous-Wave Lidar

作　　者：张恒康 王立[1] 郭绍刚[1] 李林 Zhang Hengkang;Wang Li;Guo Shaogang;Li Lin(Space Optoelectronic Measurement and Perception Lab,Beijing Institute of Control Engineering,Beijing 100190,China)

机构地区：[1]北京控制工程研究所空间光电测量与感知实验室,北京100190

出　　处：《中国激光》2023年第13期196-205,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金(52275083,51905034)。

摘　　要：调频连续波(FMCW)激光雷达具备同步高精度测距测速能力,在空间目标测量等领域中有重要应用前景。然而,目标高速运动导致雷达干涉中频信号发生频谱展宽,对测量精度形成了严重影响。为此,对FMCW激光雷达测量高速目标问题开展理论分析,建立了中频信号频谱的理论表述,利用频谱对称性的特征,提出了一种新型的基于频谱自卷积的中频频率解算算法。通过数值仿真进行验证,证实此算法可有效校正频谱展宽导致的测量误差,实现目标距离和速度的高精度测量,与传统方法相比,可在相同信噪比条件下实现测量精度三个数量级以上的提升。此算法运算量小,抗噪声干扰能力强,且应用前景广阔,对于推进FMCW激光雷达在空间碎片观测预警等空间技术领域的应用具有积极意义。Objective Frequency-modulated continuous-wave(FMCW) lidar has the ability to measure ranges and velocities of moving targets simultaneously with high precision,and thus it has great potential in numerous applications such as space debris detection and space situational awareness.The conventional measuring method is to perform fast Fourier transform(FFT) to the intermediate frequency signal,and then the peak-value frequency is used as the intermediate frequency to calculate the target range and velocity.However,this method cannot achieve high-precision measurement of high-speed targets.The high-speed movements of targets could cause spectral broadening of the intermediate frequency signal,resulting in a multi-peak spectral structure.Therefore,it is difficult to accurately find the intermediate frequency,especially in noisy environments,which has a serious impact on the measurement precision.To deal with this problem,a new spectrum analysis method is desired.In this paper,we propose a novel algorithm for calculating intermediate frequency based on self-convolution of the spectrum.By conducting numerical simulations,we verify the ability of the proposed algorithm in correcting measurement error induced by spectral broadening and realizing high-precision measurements of the target range and velocity.Meanwhile,it has small computation,strong anti-noise ability and broad application prospect.Therefore,it is of great significance for promoting the applications of FMCW lidar in space technologies.Methods A novel algorithm(Fig.3) is proposed to correct the measurement error caused by high-speed-movement-induced spectral broadening of the intermediate frequency signal,and its validity is verified by numerical simulation.With a theoretical analysis,we find that the intermediate frequency spectrum of FMCW lidar when measuring high-speed targets has the symmetry characteristics,and its center frequency has a certain relationship with target range and velocity.Therefore,as long as the center frequency is known,the target range

关 键 词：测量 激光雷达 调频连续波 频谱展宽 误差校正 

分 类 号：TN958.98[电子电信—信号与信息处理]