An Analysis for the Accuracy of Tropospheric Zenith Delay Calculated From ECMWF/NCEP Data Over Asia

Chen, Qin-Ming; Song, Shuli; Zhu, Wenyao

doi:10.1002/cjg2.1722

Cited by 16 publications

(10 citation statements)

References 11 publications

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“…In other words, the SSIEGNOS model shows high stability when used to predict the long-term ZTD time series. Figures [12][13][14][15] show that the daily predicted bias and RMS error in the SSIEGNOS model present significant stable and similar variations each year among the four IGS sites. Moreover, the SSIEGNOS model has remarkable refining results at the PIMO (Southern Asian) and TSK2 (Eastern Asian) sites, compared with the EGNOS and UNB3m models.…”

Section: Investigation Of the Long-term Time Series Of Predicted Ztdmentioning

confidence: 99%

SSIEGNOS: A New Asian Single Site Tropospheric Correction Model

Huang

Xie

Liu

et al. 2017

IJGI

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This paper proposes a new Asian single site tropospheric correction model called the Single Site Improved European Geostationary Navigation Overlay Service model (SSIEGNOS) by refining the European Geostationary Navigation Overlay Service (EGNOS) model at a single site. The performance of the SSIEGNOS model is analyzed. The results show that (1) the bias and root mean square (RMS) error of zenith tropospheric delay (ZTD) calculated from the EGNOS model are 0.12 cm and 5.87 cm, respectively; whereas those of the SSIEGNOS model are 0 cm and 2.52 cm, respectively. (2) The bias and RMS error show seasonal variation in the EGNOS model; however, little seasonal variation is observed in the SSIEGNOS model. (3) The RMS error decreases with increasing altitude or latitude in the two models; however, no such relationships were found in the bias. In addition, the annual predicted bias and RMS error in Asia are −0.08 cm and 3.14 cm for the SSIEGNOS model, respectively; however, the EGNOS and UNB3m (University of New Brunswick) models show comparable predicted results. Relative to the EGNOS model, the annual predicted bias and RMS error decreased by 55% and 48%, respectively, for the SSIEGNOS model.

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Section: Investigation Of the Long-term Time Series Of Predicted Ztdmentioning

confidence: 99%

SSIEGNOS: A New Asian Single Site Tropospheric Correction Model

Huang

Xie

Liu

et al. 2017

IJGI

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“…Integrated results indicate that ECMWF ERA-Interim has the highest accuracy. Chen et al 30 used the measured ZTD at 49 GPS stations in Asia to assess ECMWF ZTD and NCEP ZTD. Compared with GPS ZTD, Bias and RMS for ECMWF ZTD were −1.0 cm and 2.7 cm, NCEP ZTD were 2.4 cm and 6.8 cm, and ECMWF ZTD was superior to NCEP ZTD.…”

Section: Construction Of Itgmentioning

confidence: 99%

ITG: A New Global GNSS Tropospheric Correction Model

Yao

Shi

et al. 2015

Sci Rep

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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.

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“…The empirical equations proposed by Owens for

k_{1} false(λ false)

and

k_{2} false(λ false)

are as follows:

({, \begin{matrix} k_{1} false(λ false) = 0.237134 + 68.39397 \frac{130 + λ^{- 2}}{{false(130 - λ^{- 2} false)}^{2}} + 0.45473 \frac{38.9 + λ^{- 2}}{{(38.9 - λ^{- 2})}^{2}} \\ k_{2} false(λ false) = 0.648731 + 0.0174174 λ^{- 2} + 3.5575 λ^{- 4} + 6.1957 λ^{- 6} \end{matrix}) .

Approximately 90% of the total troposphere zenith delay

normalΔ L_{trop}

is caused by dry air (∼2.3 m), and the remainder is caused by wet air. Troposphere group delay correction is estimated using atmospheric data from the National Centers for Environmental Prediction (NCEP) [14].…”

Section: Methodsmentioning

confidence: 99%