地基观测空间在轨运行圆锥目标的激光多普勒频谱

The laser radar Doppler spectrum of moving conical target in its spaced orbit observed by ground-based station

利用目标坐标系下旋转圆锥目标激光多普勒频谱特征,结合一种假想运行轨道数据和空间目标坐标系、地基坐标系和地心坐标系间的变换关系,构建了空间在轨运行圆锥目标的激光多普勒频谱地基观测模型.通过3种实例,详细计算并分析了不同尺寸、粗糙表面圆锥目标以及不同地基观测方向下的激光雷达后向接收归一化功率随在轨运行时间和多普勒频移量的变化情况.数值计算表明:在轨运行的圆锥目标,其尺寸、表面粗糙度、地基坐标系下的观测方向都对多普勒频谱特征都有影响,地基激光雷达后向接收归一化功率随在轨运行时间和多普勒频移的变化都按一定规律呈周期性波动;旋转速度一定的情况下,圆锥目标尺寸越大,多普勒频移也越大;圆锥目标表面越粗糙,地基激光雷达后向接收归一化功率随在轨运行时间和多普勒频移的变化起伏越显著.本文工作对进一步开展地基观测空间在轨运行的各种复杂目标奠定了理论研究基础,将为开展空间微运动和真假目标地基激光雷达探测实验研究提供技术支持.

Utilizing the characteristics of laser Doppler spectrum of rotating conical target in target coordinate system and combining with a hypothetical spaced orbit data and transformed relationships between space target, ground-based observation and geocentric coordinate system, the model on the laser radar Doppler spectrum of moving conical target in its orbit observed by ground-based station is presented in this paper. Three applied cases are detaily calculated and analyzed that the lidar normalized power of moving conical target observed by ground-based station is changed with the time of orbit and the Doppler frequency shift in different dimensions and roughness of conical target and different ground-based observed directions. The calculated results are shown that the dimension and roughness of orbited conical target and different ground-based observed directions have influnce on their laser Doppler spectrum. The rules of the lidar normalized power changed with the time of orbit and the Doppler frequency shift is periodically fluctuated for any spaced conical targets. As the rotation speed is constant, the dimension of conic target is bigger, Doppler frequency shift is higher. The roughess of the conic surface is bigger, the fluctuatations of lidar normalized power changed with the time of orbit and the Doppler frequency shift is strongger. So our works are based on further developed to theoretically study on all kinds of spased complex targets in their orbits and furth given a technological support for laser radar observing spased complex targets with micromotion and distinguishing true/false targets in their orbits on gound-based station.