Title
The Impact of Different Ocean Tide Loading Models on GNSS Estimated Zenith Tropospheric Delay Using Precise Point Positioning Technique.
Abstract
Global navigation satellite systems (GNSSs) have become an important tool to derive atmospheric products, such as the total zenith tropospheric delay (ZTD) and precipitable water vapor (PWV) for weather and climate studies. The ocean tide loading (OTL) effect is one of the primary errors that affects the accuracy of GNSS-derived ZTD/PWV, which means the study and choice of the OTL model is an important issue for high-accuracy ZTD estimation. In this study, GNSS data from 1 January 2019 to 31 January 2019 are processed using precise point positioning (PPP) at globally distributed stations. The performance of seven widely used global OTL models is assessed and their impact on the GNSS-derived ZTD is investigated by comparing them against the ZTD calculated from co-located radiosonde observations. The results indicate that the inclusion or exclusion of the OTL effect will lead to a difference in ZTD of up to 3-15 mm for island stations, and up to 1-2 mm for inland stations. The difference of the ZTD determined with different OTL models is quite small, with a root-mean-square (RMS) value below 1.5 mm at most stations. The comparison between the GNSS-derived ZTD and the radiosonde-derived ZTD indicates that the adoption of OTL models can improve the accuracy of GNSS-derived ZTD. The results also indicate that the adoption of a smaller cutoff elevation, e.g., 3 degrees or 7 degrees, can significantly reduce the difference between the ZTDs determined by GNSS and radiosonde, when compared against a 15 degrees cutoff elevation. Compared to the radiosonde-derived ZTD, the RMS error of GNSS-derived ZTD is approximately 25-35 mm at a cutoff elevation of 15 degrees, and 15-25 mm when the cutoff elevation is set to 3 degrees.
Year
DOI
Venue
2020
10.3390/rs12183080
REMOTE SENSING
Keywords
DocType
Volume
PPP,ZTD,OTL,radiosonde,elevation cutoff angle
Journal
12
Issue
Citations 
PageRank 
18
0
0.34
References 
Authors
0
8
Name
Order
Citations
PageRank
Jinglei Zhang100.34
Xiaoming Wang200.68
Zishen Li3106.14
Shu-hui Li414.07
Cong Qiu500.68
Haobo Li600.68
Shaotian Zhang700.34
Li Li87624.03