一种辅助轨道确定的相对干涉测量方法研究

A Relative Interferometry Method for Aiding Orbit Determination in Deep Space Exploration

在嫦娥四号中继星任务期间某次干涉测量标校射电源观测无效、微卫星轨控后预报星历无法提供精确时延模型的背景下,提出了一种为微卫星轨控后轨道确定提供辅助约束测量信息的方法。该方法通过迭代相关处理修正时延模型,解决了轨控后微卫星预报星历不准的难题;利用中继星观测估计系统时延并修正微卫星干涉测量观测量,得到了实时条件下微卫星干涉测量观测信息,与事后相关处理结果的偏差约为4.2ns(约1.2m)。进一步分析了相对干涉测量中的误差因素,结果表明相对干涉测量的随机误差约2ns,与事后相关处理精度相当。最后,给出了应用于辅助探测器轨道确定的相对干涉测量数据处理方案,为后续相关背景下的干涉测量提供参考。

During the orbit control process in CE04 relay-satellite mission,a relative interferometry method is proposed for aiding orbit determination under the situation that the calibration source observation is ineffective or the time delay model from predicting ephemeris is inaccurate for interferometry. The guidance model is improved by iterative correlation processing,overcoming the problem that the predicting ephemeris is inaccurate,and then the systematic time-delay is estimated by the measurements of relay-satellite to modify that of the micro-satellite and obtain the real-time interferometry measurements for aiding orbit determination of the micro-satellite. The real-time result is compared with that of post processing which uses the accurate ephemeris,and the bias between them is about 4. 2 nanoseconds( about 1. 2 meters). Moreover,the error analysis of the relative interferometry shows that the precision of real-time is about 2 nanoseconds,which is at the nearly same level as the post result. Finally,a processing scheme of relative interferometry is established by offering a reference for the following similar situation.