基于GNSS和SLR观测数据的北斗卫星(GEO/IGSO)精密定轨

研究了联合GNSS和卫星激光测距（satellite laser ranging，SLR）观测数据对北斗卫星定轨精度的影响。仅利用GNSS观测值对北斗卫星进行定轨时，C01、C08和C10卫星的SLR检核结果显示，这3颗卫星的SLR残差均存在一定的偏差且不相同。加入SLR观测值联合定轨时，分别对估计和不估计系统偏差的卫星轨道结果进行分析。结果显示，对C01（GEO）卫星加入SLR观测值时必须引入系统偏差，否则会使轨道偏离；C08和C10（IGSO）卫星估计和不估计系统偏差时对预报轨道的精度均有一定的改善。最后统计了这3颗卫星的系统偏差，C01卫星的系统偏差达到50 cm，C08和C10卫星的系统偏差在5 cm以内。

Orbit Determination of BDS GEO and IGSO Satellites Using Combined GNSS and SLR Observations

We assess the orbit quality of BDS GEO and IGSO satellites, based on global navigation satellite system(GNSS) and satellite laser ranging(SLR) observations. When using GNSS observations for BDS orbit determination, the results show that the SLR residuals of C01, C08 and C10 have a certain degree of deviations, and that the values from the satellites are not identical. In combined orbit determination using GNSS and SLR observations, the orbit accuracy with SLR range biases estimated and not estimated are analyzed. The results show that SLR range biases must be estimated for C01 due to a large bias in GNSS-only solution. There is a certain degree of improvement in orbit prediction for C08 and C10, using the combined solution with estimating SLR range, bias or not. In addition, statistics of range biases for C01 is about 50 cm and less than 5 cm for C08 and C10.