同波束干涉测量差分相位计算与DOR时延精度验证

Calculation of Differential Phases in Same-beam VLBI and Accuracy Verification of DOR Delay

同波束干涉测量可以获取多航天器间高精度相对角位置信息。但对于两航天器间匹配频点少、频点间频差大、观测非连续条件下如何获取高精度的相对角位置观测量仍然是一个尚待解决的问题。我国在嫦娥二号(CE-2)卫星上首次搭载了差分单程测距(DOR)信标,用于测量技术测试验证,如何对DOR信号带宽综合时延进行精度验证也是本文关心的问题。文中提出基于相位补偿的差分相位解算方法,并基于DOR多频点信号测量数据进行了方法验证。给出DOR带宽综合解算方法,分析DOR无模糊解算条件;通过合理设置采样通道,实现了由单通道群时延验证DOR带宽综合时延。嫦娥二号卫星实测数据分析表明,相位补偿法可以得到反映航天器间相对角位置的差分相位观测量;DOR带宽综合时延与单通道时延解算结果一致,且时延解算精度有显著提高。

High accuracy relative angle position between multi-spacecraft can be obtained using same-beam VLBI observation. In many missions, the number of matched frequency pair between two spacecrafts is very limited, The frequency difference in frequency pair might be large. The observation cannot be executed continuously sometimes, It will be very difficult to get high accuracy relative angle position in such conditions. DOR radio signal source was firstly onboard the Chinese lunar satellite, Chang＇E-2 satellite （CE-2）, which was used to testify tracking technology. It was also discussed in the paper that how to verify the accuracy of the differential one-way range （DOR） obtained by bandwidth synthesis. A new method named phase compensation was proposed to get phase difference, which was verified by analyzing DOR frequencies, The method of DOR bandwidth synthesis was given. The conditions of solution without the ambiguities were discussed. DOR delay was testified using the delay of single channel when proper sampling channels were designed, Analyzed results of Chang＇E-2 satellite observation data show that phase difference can be obtained using phase compensation method. DOR delay is in accordance with and more accurate than delay of single channel.