TLE数据误差与基于TLE数据的交会预报分析

TLE Accuracy Analysis and Conjunction Prediction

目前普遍使用TLE数据进行在轨物体的危险交会预报.TLE数据误差不仅会影响交会预报的准确性,还是计算碰撞概率的必要参数,因此,只有准确估计TLE数据误差,才能得到可信的碰撞概率数值.本文采用两种方法,即TLE数据自比和与高精度轨道预报数据相比较的方法,计算TLE数据误差,并分别利用TLE数据和高精度数据计算同一交会,比较两种数据预报的交会结果差异.结果表明,采用TLE根数自比方法的计算误差偏小,而使用精轨数据作为校准数据所得到的TLE误差更接近真实误差,计算碰撞概率更为合理,有利于减少虚警.

Two Lines Elements（TLE） were widely used for on-orbit conjunction prediction.The accuracy of TLE data had great impact on conjunction prediction results,and was one of the necessary parameters for collision probability calculation.Only if the predicted position accuracy of TLE data were calculated exactly,the value of collision probability is reliable.In the research,the TLE position accuracy was calculated based on two kinds of criterion data,including updated TLE data and Consolidated Prediction Format（CPF） data,whose predicted position was more accurate than TLE data.The TLE position accuracy based on CPF data was used for true TLE position accuracy.Besides,both CPF data and TLE data were used for calculating conjunctions of satellites. CPF data was used for validating the conjunction results calculated based on TLE.The results of the research showed that the position accuracy based on updated TLE data was a little smaller than the true value.So in general cases,the collision probabilities were a little higher,which could be one reason for why conjunction predictions based on TLE were contained of a lot of fake results.With TLE data position accuracy based on CPF instead of updated TLE data,the conjunction results calculated with TLE data might be more reasonable.