Determining the Reasonable Time Resolution of the Precise Satellite Clock Bias Products

The GPS precise satellite clock bias produced by IGS analysis centers is widely used; the time resolution is 5 s, 30 s, 5 min, and 15 min, respectively. However, the determination of the reasonable time resolution is lacking in theoretical and experimental research. On one hand, high time resolution can improve the data accuracy and reliability of post-processing applications. On the other hand, it could lead to a large quantity of data. Thus, both the accuracy and data quantity should be comprehensively considered. Firstly, this paper analyzed the variation of the precise satellite clock bias in detail using the epoch-differenced method and interval fitting method. Secondly, the periodicity of the 5-s GPS precise satellite clock bias was analyzed using spectrum analysis. Non-negative matrix factorization was then employed to extract the intrinsic feature dimension and determine the time resolution of the precise GPS satellite clock bias. Finally, it was suggested that the best time resolution is one minute. The results can also be used as reference for the BDS precise satellite clock bias.