【作者】 陈俊宇； 李彬； 章品； 杜建丽； 陈立娟； 桑吉章；

【Author】 Chen Junyu;Li Bin;Zhang Pin;Du Jianli;Chen Lijuan;Sang Jizhang;School of Geodesy and Geomatics,Wuhan University;Collaborative Innovation Center for Geospatial Technology;

【机构】 武汉大学测绘学院； 地球空间信息技术协同创新中心；

【摘要】 稀疏数据条件下,弹道系数是影响低轨空间碎片精确轨道确定与预报的关键因子。使用长期累积的TLE(二行参数)跟踪数据,通过半长轴的大气阻力摄动方程,将两千多个轨道高度低于850km的空间碎片的弹道系数进行估算,得到这些空间碎片的弹道系数值,并给出弹道系数的四个应用实例。第一个应用实例关于利用弹道系数进行TLE的数据质量检测。使用质量检测方法剔除质量可疑的TLE后,对14个面质比较大的空间碎片进行弹道系数的重新估算,估算误差均显著减小,其中11个新计算得到的弹道系数与参考值的相对误差小于20%。第二个应用表明了碎片轨道确定与预报过程中已知弹道系数的重要性。在弹道系数固定时,使用2次光学通过光学观测值进行某一碎片的轨道确定,第5天的轨道预报误差在120"以内。第三个实例展示了验证弹道系数在所谓的TLE-OD/OP方法中的应用。以GRACE-B卫星为例,精密轨道预报为参考,结果表明利用多组TLE的TLE-OD/OP的轨道预报精度显著优于TLE/SGP4的精度。第四个应用展示了弹道系数在大气质量密度模型校正中的作用。利用TLE数据对DTM78模型进行校正,结果表明,大部分碎片的轨道预报精度得到了改善。更多还原

【Abstract】 It has been found that ballistic coefficient(BC) is a critical parameter in LEO debris orbit determination(OD) and orbit predication(OP) while using sparse tracking data.BC of more than 2000 space debris objects with perigee height below 850 km are estimated using the long-archived two-line elements(TLE) data and the drag perturbation equation of the semi-major axis of the orbit.4 applications of estimated BCs are discussed.In the first experiment,BCs of 14 LEO debris objects with high area to mass ratio(HAMA) are re-computed after TLEs of suspicious quality are removed through a TLE quality examination process in which the BC value is used to estimate a reasonable variation of the mean semi-major axis.Consequently,the errors of all the re-computed BCs are reduced.In the second experiment,BC is fixed in orbit determination of a LEO when optical tracking data of only 2 passes is available,and the errors of orbit predictions for 5 days are mostly smaller than 120 arc seconds.In the third experiment,BC of GRACE-B is used as initial value in the so-called TLE-OD/OP method.It is confirmed that the TLE-OD/OP method results in better OP accuracy when compared to standard Simplified General Perturbations-4(SGP4) propagation.The importance of known BCs in the atmospheric mass density model calibration(ADMC) isdemonstrated in the fourth experiment,where the DTIM78 is calibrated using TLE data.Results show that most of the debris objects have better OP accuracy after the use of calibrated DTM78 model.更多还原