样本量对空间碎片测距精度的影响

日益增多的空间碎片严重威胁着在轨航天器的运行安全，对空间碎片的监督与防御逐渐引起了关注。高重复率激光测距技术为空间碎片测量提供了有效手段。激光脉冲的高重复率意味着大样本量。而在满足精度要求下，对样本量需求的研究较少。本文基于高重复率取样，研究了样本量对测距精度的影响，并得到了满足精度要求的最小样本量。首先，将空间碎片的轨道根数作为先验信息对测量数据进行预处理。通过多项式拟合和迭代获得有效样本点，逐渐减少样本量，绘制精度随样本量的变化曲线。从精度曲线变化阈值中可以获得最小样本量，可以此选取激光测距系统激光发射重复频率。对一些空间碎片的测距实验结果表明，有效样本量可以获得30%—60%的降低。

Effect of Sample Quantity on Space Debris Ranging Precision

The increasing number of space debris has drawn public attentions, as the safety of spacecraft is severely threatened. Luckily, high-repetition-rate laser ranging technology provides an effective way for space debris measurements. The high repetition rate of laser pulses brings along a large sample quantity, while there is little research about the demanded sample quantity for the needed ranging precision. In this study, the effect of sample quantity on ranging precision is researched based on the high-repetition sampling, and the minimum sample quantity is obtained. Firstly, the orbit elements of space debris is applied as the priori information for preprocessing. Then the effective samples are obtained by polynomial fitting and iteration. By gradually decreasing the sample quantity, a precision-sample quantity curve is drawn, where the minimum sample quantity can be estimated form the threshold in the curve. Based on the minimum sample quantity, the transmitted repetition rate of the laser ranging system can be adjusted. Experimental results for some space debris show that the effective sample quantity can be decreased by about 30%-60% based on the current system parameters.