嫦娥二号探测器轨道确定与支持

针对嫦娥二号探测器直接进入地月转移轨道、距月面100km高度捕获月球、完成既定任务后飞往日地第二拉格朗日平动点等飞行轨道方面的新特点，分析了定轨预报策略，利用事后精密轨道，全面评估了关键变轨点定轨预报和变轨后快速定轨的精度，其中，近月制动前3h定轨预报至近月点的位置误差为1km，速度误差为 0.3m/s 。利用不同月球引力场模型进行环月轨道精密定轨，根据实测数据残差分析和精密星历比对的结果，采用SGM100h引力场模型的定轨残差均方根最大。此外，针对嫦娥二号扩展任务，分析了不同测轨条件下的定轨精度，测量数据残差分析结果表明，在扩展任务中途修正前的定轨弧段内，测距、时延和时延率数据的残差分别为5m，5ns和1ps/s。

Chang’E-2 Lunar Probe Orbit Determination and Support

Several key techniques are validated by Chang’E-2 (CE 2), including the direct transfer trajectory to moon and the lunar orbit insertion maneuver at 100km altitude, etc. Then, an extended mission to sun earth Lagrangian point L2 was carried out. For new characteristics of the trajectories, mission design and orbit determination strategy are presented. Based on post processed precision ephemeris, the orbit determination and prediction accuracy of pre maneuvers is evaluated and fast assessments of post maneuvers are performed. Based on orbit determination results before lunar insertion, the 3 hour predicted position error of perilune is 1km and the velocity error is 0.3m/s. A comparison of the orbit determination results with 3 different lunar potential field models is presented. The analysis of measurement residuals and post processed ephemerides shows that RMS of the residuals using SGM100h is the maximal of all. Furthermore, orbit determination accuracy of the different types of measurements is evaluated for CE 2 extended mission. Measurement residuals are analyzed based on pre TCM precision ephemeris. The RMS of data residuals including ranging, time delay and time delay rate are respectively 5m, 5ns and 1ps/s.