ABSTRACT

The international GNSS service (IGS) started publishing the precise ephemeris files in the form of the standard products #3, version C (the sp3c files) in which the GPS satellite orbits and clocks and their uncertainties were available since 2004. Incorporating these uncertainties into the GPS observation equations results in a better stochastic model of the processing system. The reality of these uncertainties is questioned and studied in this paper. Precise point positioning (PPP) model, statistical tests and variance component estimation (VCE) techniques are employed for this study. The results confirm the efficiency of the proposed method in the assessment of reality of the published ephemeris uncertainties.

摘要

自 2004 年以来，国际 GNSS 服务 (IGS) 开始以标准产品 #3 版本 C（sp3c 文件）的形式发布精确星历文件，其中 GPS 卫星轨道和时钟及其不确定性可用。将这些不确定性纳入GPS观测方程产生了更好的处理系统随机模型。本文对这些不确定性的真实性进行了质疑和研究。本研究采用精确点定位（PPP）模型、统计检验和方差分量估计（VCE）技术。结果证实了所提出的方法在评估已发布的星历不确定性的现实中的有效性。