多系统GNSS卫星钟差和偏差产品综合：IGS第3次重处理

耿江辉; 闫哲; 温强

doi:10.13203/j.whugis20230071

摘要: 2019年10月，国际卫星导航服务组织（international GNSS service, IGS）开始了第3次重处理（the third data reprocessing campaign, repro3），对各分析中心的全球卫星导航定位系统（global navigation satellite system, GNSS）卫星钟差和偏差产品（包括伪距偏差和相位偏差）进行综合成为其重要任务之一。提出了多系统GNSS卫星钟差和偏差产品综合的模型和方法，并受IGS协调分析中心委托，对repro3发布的2000—2020年的钟差和偏差产品进行综合。通过对产品综合情况进行统计与分析，得出如下结论：各GNSS系统的综合钟差产品完整率稳定后可达到95%以上，优于多数分析中心产品；GPS和伽利略卫星导航系统（Galileo satellite navigation system, Galileo）卫星钟差间的综合均方根误差分别达到6.13 ps和5.63 ps，证明了综合方法中的各项改正模型能显著提升产品一致性；格拉茨技术大学产品参与合并的平均权重达到21.83%，其相对精度优于其他分析中心；基于相位偏差产品的钟差合并权重整体高于传统卫星钟差，稳定性和精度更优。此外，为了验证综合产品的定位性能，选取了全球均匀分布的103个测站进行精密单点定位静态解测试，结果表明：基于综合产品的GPS卫星宽巷、窄巷模糊度的平均固定率分别为90.16%和86.72%，Galileo卫星分别为97.11%和93.77%，较基于欧洲定轨中心（Center for Orbit Determination in Europe, COD）重处理产品的定位结果整体提升约1~5百分点；使用综合产品在东、北、天方向的平均定位精度分别为0.154、0.178、0.542 cm，相比COD提升了20%~30%。IGS repro3的综合钟差和偏差产品已在IGS官方网站提供下载（https://cddis.nasa.gov/archive/gnss/products/repro3/）。

Abstract:

Objectives In October 2019, the International GNSS Service(IGS) began the third data reprocessing campaign(repro3). To enable more robust ambiguity resolution(AR) in precise point positioning(PPP), one of IGS important tasks is to combine satellite clock and code/phase bias products.

Methods We elaborated the precise satellite clock product model, code/phase bias product model, as well as prior corrections and specific processes for the combination of global navigation satellite system(GNSS) satellite clock and code/phase bias products. What?s more, entrusted by the IGS Analysis Center Coordinator, we combined the clock/bias products of repro3 from 2000 to 2020 successfully.

Results Through the statistics of the combination, it is concluded that the integrity rate of combined clock can reach more than 95% after stabilization, which is superior to most of the products of IGS Analysis Centers. The average root mean square error of GPS and Galileo satellite navigation system satellite clock reach 6.13 ps and 5.63 ps respectively, which prove that the correction models in the combination can significantly improve the consistency.The average weight of Graz University of Technology participating in the combination reaches 21.83%, which has better precision than that of other analysis centers. The weight of phase/integer clock is higher than that of legacy clock, with better stability and precision. Furthermore, 103 stations with uniform global distribution were selected for the static PPP-AR solution to validate the positioning precision of the combined products. The results showed that the average fixed rates of GPS wide and narrow-lane ambiguity based on combined products are 90.16% and 86.72% respectively, and those of Galileo are 97.11% and 93.77% respectively, which are about 1-5 percentage points higher than those based on Center for Orbit Determination in Europe (COD) repro3 products. The average positioning precision based on combined products in the east, north and high directions is 0.154, 0.178 and 0.542 centimeters respectively, which is 20% to 30% higher than COD.

Conclusions The multi-GNSS satellite clock and code/phase combination method can effectively solve the problems of the consistency among products of analysis centers, and enable more robust ambiguity resolution in PPP-AR. Moreover, the combined products have been officially downloaded (IGSMAIL-8248:https://cddis.nasa.gov/archive/gnss/products/repro3/).

多系统GNSS卫星钟差和偏差产品综合：IGS第3次重处理

Multi-GNSS Satellite Clock and Bias Product Combination: The Third IGS Reprocessing Campaign