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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 ITG pressure coefficients. This map was generated as the same way with Fig. 1(a) average (b) absolute amplitude of annual cycle(c) absolute amplitude of semi-annual cycle (d) absolute amplitude of diurnal cycle.
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f2: Global distribution of ITG pressure coefficients. This map was generated as the same way with Fig. 1(a) average (b) absolute amplitude of annual cycle(c) absolute amplitude of semi-annual cycle (d) absolute amplitude of diurnal cycle.

Mentions: Parameters of ITG include temperature, pressure, Tm, ZWD and temperature lapse rate. They are modeled with the output of ECMWF ERA-Interim in 2001-2010 (spatial horizontal resolutions are 2.5° × 2.5°, temporal resolution is 6 hours) as the method introduced in section 3.2. From this, we can obtain the global gridded coefficients of temperature, pressure, Tm, ZWD and temperature lapse rate at the surface. Taking temperature, pressure and ZWD, for example, the global distribution of several coefficients are shown in figs. 1, 2, 3.


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 ITG pressure coefficients. This map was generated as the same way with Fig. 1(a) average (b) absolute amplitude of annual cycle(c) absolute amplitude of semi-annual cycle (d) absolute amplitude of diurnal cycle.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f2: Global distribution of ITG pressure coefficients. This map was generated as the same way with Fig. 1(a) average (b) absolute amplitude of annual cycle(c) absolute amplitude of semi-annual cycle (d) absolute amplitude of diurnal cycle.
Mentions: Parameters of ITG include temperature, pressure, Tm, ZWD and temperature lapse rate. They are modeled with the output of ECMWF ERA-Interim in 2001-2010 (spatial horizontal resolutions are 2.5° × 2.5°, temporal resolution is 6 hours) as the method introduced in section 3.2. From this, we can obtain the global gridded coefficients of temperature, pressure, Tm, ZWD and temperature lapse rate at the surface. Taking temperature, pressure and ZWD, for example, the global distribution of several coefficients are shown in figs. 1, 2, 3.

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.