北斗GEO卫星CEI相时延解算方法研究

连线端站干涉测量(connected element interferometry，CEI)是高精度测角技术，在中高轨卫星、月球及深空航天器定轨定位中有良好的应用前景。基于CEI技术特点，提出了一种新的测量方法，即在相干测距模式下利用测距音和载波信号作为信号源进行连线端站干涉测量。构建了CEI试验系统对北斗GEO卫星进行观测，利用相干测距模式下的下行信号解算群时延、相时延。利用北斗GEO卫星精密星历计算的时延理论值，对北斗GEO卫星CEI群时延和相时延结果进行评估。结果表明，相干测距模式下CEI群时延和相时延残差均值分别为0.47ns、0.08ns，标准差(3σ)分别4.2ns、0.13ns。该项研究验证了相干测距模式下CEI相时延解算的可行性，可为共位地球同步卫星精密相对定位、月球探测器CEI测量提供技术参考。

Research on CEI phase delay resolving method for BDS GEO satellite

Connected element interferometry (CEI) is a precision angular measurement technology widely used in the orbit determination of MEO satellites, GEO satellites, lunar probes and deep space probes. A new measurement mode was proposed based on the characteristics of CEI. The carrier and ranging signals in coherent ranging mode were used in CEI. A CEI system was established and used to observe BDS (BeiDou navigation satellite system) GEO satellite. Group delay and phase delay were calculated by using all these signals. Group delay and phase delay results of the BDS GEO satellite were estimated by using the theoretical delay values calculated by precision ephemeris. The results show that the means of the residual of group delay and phase delay is 0.47ns and 0.08ns, and that the standard deviation (3σ) of the residual of group delay and phase delay is 4.2ns and 0.13ns. The feasibility of the phase delay calculation of CEI in coherent ranging mode is verified. This paper can provide reference for precision orbit determination of co-location GEO satellites, lunar probes and deep space probes.