基于Lomb-Scargle谱分析的分析中心GPS精密产品特性分析及修正

Characteristic analysis and correction of GPS precise products in analysis centers based on Lomb-Scargle periodogram

考虑到国际GNSS服务(IGS)提供的精密产品相对于全球大地测量观测系统(GGOS)时空基准准确度1 mm的要求仍存在量级差异,采用Lomb-Scargle谱分析算法分析了GNSS各分析中心精密产品与IGS最终精密产品之间的系统性偏差、周期性偏差,并在此基础上基于最小二乘法建立了偏差修正模型用于精密参数的修正.偏差修正结果表明,修正后卫星钟差标准差平均减小15.4%,卫星轨道径向标准差平均减小33.3%,卫星轨道径向与钟差综合偏差的标准差平均减小24.0%,同时空间信号测距误差也从cm量级降低至mm量级.15个测站的定位验证结果表明,偏差修正后使用单分析中心精密产品的定位误差与使用IGS最终精密产品定位误差的一致性有所提升,3个分析中心的定位误差一致性平均提升比例为14.3%,证明了该偏差修正模型能够有效提升GNSS各分析中心精密产品与IGS最终精密产品的一致性.

Considering that the precise orbit and clock products provided by international GNSS service(IGS)were of order of magnitude difference from those required by the global geodetic observing system(GGOS)in accuracy of 1 mm,the Lomb-Scargle periodogram was used to analyze the systematic deviation and the periodical deviation between the precise products of GNSS analysis centers(ACs)and the IGS final precision products.On this basis,a deviation correction model was established based on the least square method for the correction of precision parameters.The deviation correction results show that the standard deviation of the precise clock decreases by 15.4%,the standard deviation of the radial orbit decreases by 33.3%,and the standard deviation of the ensemble effects of radial orbit and clock decreases by 24.0%on average.The signal-in-space user ranging error(SISURE)also significantly decreases from the level of centimeters to millimeters.The positioning verification results of the 15 stations show that the consistency between the positioning errors of the precision products using single AC and the positioning errors of final precision products of IGS is also improved after the deviation correction,and the average improvement ratio of the positioning error consistency of three ACs is 14.3%.It is proved that the deviation correction model can effectively improve the consistency between the precision products of ACs and the final products of IGS.