GNSS数据处理时空参数的相关性

Correlation of Spatial and Temporal Parameters in GNSS Data Analysis

卫星轨道、钟差以及测站坐标等是全球导航卫星系统定位(global navigation satellite system,GNSS)的核心参数,构成了卫星导航系统数据处理的时空基准。通过比较国际GNSS服务(International GNSS Service,IGS)不同数据分析中心提供的GNSS精密时空产品发现,各分析中心的轨道、钟差存在明显差异,并且轨道、钟差的相对偏差存在很强的相关性。针对该问题,讨论了GNSS卫星轨道、钟差的相关性问题,分析了轨道、钟差相对偏差的周期特性,并提取了周期项模型参数;建立改正模型,提高了不同分析中心产品的一致性;对时空基准周期性误差的原因进行了分析,并以参数降相关为出发点,对GNSS时空基准精度提升的方法提出了建议。

A time system and reference frame are two fundamental parameters in a satellite navigation system（GNSS）,which consists of coordinates and clocks of satellites and stations.A comparison of these precise parameters of IGS Analysis Center shows apparent differences.The differences include constant offsets and periodical signals,where the periodical signals of satellite orbits and satellite clocks are highly correlated.We analyzed the characteristics of the periodical signals and derived their amplitudes and frequencies.The derived periodical terms were applied for the correction of AC satellite orbits and clocks.The numbers of epochs where the agreement between AC precise products increased,amounted to 95.3% and 85.6% of all samples for orbits and clocks,respectively.Furthermore,the error in such signals was analyzed and strategies based on the parameter de-correlation are proposed for the GNSS precise data processing.