用于航天器振动测量的激光雷达微弱信号提取技术

Weak Lidar-signal Extraction for Vibration Measuring of Spacecrafts

基于激光雷达的飞行振动参数测量可避免现有振动测点点式分布的现状,实现振动物理量场测量。同时,由于具有非接触测量的特点,还可解决现有振动传感器与飞行器测点间刚性连接安装问题以及振动测量过程中由于滤波器设置产生的测量不准确的问题。然而航天器内、外部空间结构复杂、仪器设备空间投影平面重叠多,因此用于航天器飞行状态下弹箭上振动测量的激光雷达回波信号极为微弱,仅占全部回波信号的10-11~10-6倍,极大程度上被淹没于噪声信号中,因此该系统对于微弱信号提取要求极高。从激光雷达回波方程和信噪比公式出发,从理论上分析了微弱信号提取和背景抑制所需关注的要素,同时也给出了用于航天器飞行中振动微弱信号提取的方法及其对比。

Vibration measurement with lidar can overcome discrete detection for spacecrafts-vibration,which field detection is researched more frequently and reasonable recently.Besides,lidar-vibration detection,owning to the characteristics of non-connecting,improves the reliability and maneuverability during the entire vibration measurements with traditional sensors.In addition,this brand new method successfully avoids the common filter-caused measurement issue.However,such lidar-vibration management,consulting the extremely complicated both inside and outside structure,as well as the overlapped reflection on the spacecraft vertical plane of its flight axial,depends much on the quality of returning signal.Occupies only 10-11~10-6 ratio amplification compared with the normal one,this lidar signal belongs to a weak signal and should be extracted exactly.According to the equation of lidar returning signal and the equation of SNR(Signal-Noise Ratio),four main factors on weak signal extraction and background prehension are announced.And an whole-package management is motioned in the end.