Method for evaluating real-time GNSS satellite clock offset products
Real-time satellite clock offset products are frequently utilized in navigation and positioning service fields. The precision of such products is a key issue for their application. The evaluation methods existed for satellite clock offset products are mostly based on post-processed satellite clock offset solutions, which will encounter problems in real-time product evaluation, especially for real-time satellite clock offset products estimated from data with regional stations only. We propose an improved evaluation method for global navigation satellite system (GNSS) satellite clock offset products. In the proposed method, we use all-satellite reference method instead of single-satellite reference method to eliminate the timescale in satellite clock offset products. Moreover, a preprocessing step is suggested to detect gross errors and initial clock bias before evaluating the precision of the satellite clock offsets. We conduct two examples to verify our method, and the experimental results show that the proposed method is more reasonable in assessing the GNSS satellite clock offset precision, and it also provides a reliable approach to analyzing the estimated satellite clock offset in both real-time and post-processed, or globally and regionally.
KeywordsReal-time Satellite clock offset Initial clock bias All-satellite reference Precision evaluation
We are grateful to anonymous reviewers for their valuable comments and suggestions. The IGS is recognized for providing the post-processed clock products and also appreciate the National Administration of Surveying, Mapping and Geoinformation providing the real-time clock in China region. This study was supported by State Key Research and Development Program (2016YFB0501802) and by National Natural Science Foundation of China (Nos 41231174, 41574028 and 41404010) and by Open Research Fund of State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing (Grant No.15P01).
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