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ITG: A New Global GNSS Tropospheric Correction Model.

Yao Y, Xu C, Shi J, Cao N, Zhang B, Yang J - Sci Rep (2015)

Bottom Line: The amplitude and initial phase of diurnal variation are estimated as a periodic function.ITG provides temperature, pressure, the weighted mean temperature (Tm) and Zenith Wet Delay (ZWD).Results indicate that ITG offers the best performance on the whole.

View Article: PubMed Central - PubMed

Affiliation: 1] School of Geodesy and Geomatics, Wuhan University, 129 Luoyu Road, Wuhan, 430079, China [2] Key Laboratory of Geospace Environment and Geodesy, Ministry of Education, Wuhan University, 129 Luoyu Road, Wuhan, 430079, China.

ABSTRACT
Tropospheric correction models are receiving increasing attentions, as they play a crucial role in Global Navigation Satellite System (GNSS). Most commonly used models to date include the GPT2 series and the TropGrid2. In this study, we analyzed the advantages and disadvantages of existing models and developed a new model called the Improved Tropospheric Grid (ITG). ITG considers annual, semi-annual and diurnal variations, and includes multiple tropospheric parameters. The amplitude and initial phase of diurnal variation are estimated as a periodic function. ITG provides temperature, pressure, the weighted mean temperature (Tm) and Zenith Wet Delay (ZWD). We conducted a performance comparison among the proposed ITG model and previous ones, in terms of meteorological measurements from 698 observation stations, Zenith Total Delay (ZTD) products from 280 International GNSS Service (IGS) station and Tm from Global Geodetic Observing System (GGOS) products. Results indicate that ITG offers the best performance on the whole.

No MeSH data available.


Global distribution of ZTD Bias/RMS difference for ITG. This map is generated as the same way with Fig. 4.
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f5: Global distribution of ZTD Bias/RMS difference for ITG. This map is generated as the same way with Fig. 4.

Mentions: Figure 5(a) shows that biases are more likely to be negative at stations inland and in Antarctica, while they are positive at the sea or nearby. Fig. 5(b) indicates that RMS at high latitudes is generally smaller than at lower latitudes. Stations in Japan, eastern China, northern Australia, eastern America and southeast South America exhibit an RMS of larger than 4 cm, while most stations in Europe have an RMS of less than 4 cm. In addition, 64% of the stations overall had an RMS of less than 4 cm.


ITG: A New Global GNSS Tropospheric Correction Model.

Yao Y, Xu C, Shi J, Cao N, Zhang B, Yang J - Sci Rep (2015)

Global distribution of ZTD Bias/RMS difference for ITG. This map is generated as the same way with Fig. 4.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4508915&req=5

f5: Global distribution of ZTD Bias/RMS difference for ITG. This map is generated as the same way with Fig. 4.
Mentions: Figure 5(a) shows that biases are more likely to be negative at stations inland and in Antarctica, while they are positive at the sea or nearby. Fig. 5(b) indicates that RMS at high latitudes is generally smaller than at lower latitudes. Stations in Japan, eastern China, northern Australia, eastern America and southeast South America exhibit an RMS of larger than 4 cm, while most stations in Europe have an RMS of less than 4 cm. In addition, 64% of the stations overall had an RMS of less than 4 cm.

Bottom Line: The amplitude and initial phase of diurnal variation are estimated as a periodic function.ITG provides temperature, pressure, the weighted mean temperature (Tm) and Zenith Wet Delay (ZWD).Results indicate that ITG offers the best performance on the whole.

View Article: PubMed Central - PubMed

Affiliation: 1] School of Geodesy and Geomatics, Wuhan University, 129 Luoyu Road, Wuhan, 430079, China [2] Key Laboratory of Geospace Environment and Geodesy, Ministry of Education, Wuhan University, 129 Luoyu Road, Wuhan, 430079, China.

ABSTRACT
Tropospheric correction models are receiving increasing attentions, as they play a crucial role in Global Navigation Satellite System (GNSS). Most commonly used models to date include the GPT2 series and the TropGrid2. In this study, we analyzed the advantages and disadvantages of existing models and developed a new model called the Improved Tropospheric Grid (ITG). ITG considers annual, semi-annual and diurnal variations, and includes multiple tropospheric parameters. The amplitude and initial phase of diurnal variation are estimated as a periodic function. ITG provides temperature, pressure, the weighted mean temperature (Tm) and Zenith Wet Delay (ZWD). We conducted a performance comparison among the proposed ITG model and previous ones, in terms of meteorological measurements from 698 observation stations, Zenith Total Delay (ZTD) products from 280 International GNSS Service (IGS) station and Tm from Global Geodetic Observing System (GGOS) products. Results indicate that ITG offers the best performance on the whole.

No MeSH data available.