|
Abstract The tropospheric delay is an important GNSS error source. To reduce this error, the zenith tropospheric delay (ZTD,with 5 min, 1 h, and 2 h time resolution) produced by IGS analysis centers is widely used for satellite navigation and positioning. However, the reasonable or normalized time resolution of ZTD product treated as one data resource is lacking in theoretical and experimental research. On one hand, high time resolution can improve the modeling accuracy of related applications. On the other hand, it could lead to both large redundant data for storage and time consuming for processing when modeling accuracy approaches nominal accuracy. Thus, the reasonable time resolution of ZTD should be investigated by understanding the advantages and disadvantages. Firstly, this paper analyzed the variation of the ZTD in detail using the epoch-differenced method and interval fitting method. Secondly, the periodicity of the 5-min ZTD was analyzed using L-S spectrum analysis. Then, the singular value decomposition algorithm was employed to extract the singular value ratio of ZTD data matrix with different time resolution and determine the reasonable time resolution of the ZTD products. Finally, it was suggested that the reasonable time resolution is normalized by 30 minutes. The results can also be used as reference for the international GNSS service(IGS).
|
|
