角反射器形状效应对卫星激光测距系统测距精度的影响

Influence of Shape Effect of Angle Reflector on Ranging Precision of Satellite Laser Ranging System

基于卫星激光测距(SLR)系统的测距原理,对从角反射器反射的回波光子分布进行数值仿真,分析并讨论了卫星角反射器形状效应与SLR系统测距精度的关系。另外,为验证卫星角反射器形状效应的适用性,利用中国科学院国家天文台长春人造卫星观测站SLR系统对不同轨道高度的卫星进行了实测。结果表明,卫星角反射器形状效应使从卫星反射的回波光子分布发生明显改变,激光脉冲被展宽。对于Starlette卫星,激光脉冲脉宽由50ps展宽至72ps,由卫星角反射器形状效应引起的测距误差约为5.4 mm。对于高轨Etalon-1卫星、中轨LAGEOS-1卫星和低轨LARES卫星,由卫星角反射器形状效应引起的测距误差分别约为15.4,7.4,5.0mm。因此,要使SLR系统测量精度向毫米级发展,应当考虑卫星角反射器形状效应对测距精度的影响,这也为SLR系统的性能评估与结构设计提供了新的思路与途径。

Based on the ranging principle of satellite laser ranging （SLR） system, the distribution of echo photon reflected back from the angle reflector is simulated numerically, and the relationship between the shape effect of the satellite angle reflector and the ranging precision of SLR system is analyzed and discussed. In addition, in order to verify the applicability of the shape effect of the satellite angle reflector, the satellites at different orbits are observed by the SLR system in Changchun Observatory, National Astronomical Observatories, Chinese Academy of Sciences. The results show that the shape effect of the satellite angle reflector has significantly changed the distribution of the echo photons reflected from the satellites, and the laser pulse width is broadened. For Starlette, the laser pulse width is extended from 50 ps to 72 ps, and the ranging error caused by the shape effect of the satellite angle reflector is about 5.4 ram. For the high-orbit Etalon-1 satellite, the middle-orbit Lageos-1 satellite and the low-orbit LARES satellite, the ranging errors are about 15.4, 7.4, 5.0 mm, respectively. Therefore, for the development of the measurement accuracy of SLR system to the mm level, the influence of the shape effect of the satellite angle reflector on the ranging precision should he considered, which also provides new ideas and approaches for the evaluation t）erformance and structure design of SLR system.