An improved global zenith tropospheric delay model GZTD2 considering diurnal variations

Yao, Yibin; Hu, Yufeng; Chen, Yu; Bao, Zhenan; Guo, JianJian

doi:10.5194/npg-2016-9

Cited by 3 publications

(3 citation statements)

References 7 publications

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“…First, after extracting the five model coefficients of the given grid point and inputting the 𝑑𝑜𝑦, the Gaussian coefficients b and c were calculated using Equation (6). Second, after inputting the starting and target heights, the ZTD of the target height was calculated using Equation (9). The NGZTD-H model can achieve vertical adjustment of the ZTD from the starting height to the target height before horizontal interpolation, which reduces the interpolation errors.…”

Section: Development Of the Ngztd-h Modelmentioning

confidence: 99%

“…The Black model was developed as a new-generation model that follows the Hopfield model, which also requires the input of temperature and pressure. The accuracy of the abovementioned models can reach a centimeter level, provided that the measured meteorological parameters are available [9]. However, the measured meteorological parameters can only be obtained from stations equipped with meteorological sensors.…”

Section: Introductionmentioning

confidence: 99%

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A New Grid Zenith Tropospheric Delay Model Considering Time-Varying Vertical Adjustment and Diurnal Variation over China

Zhang,

Zuo,

Guo

et al. 2024

Remote Sensing

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Improving the accuracy of zenith tropospheric delay (ZTD) models is an important task. However, the existing ZTD models still have limitations, such as a lack of appropriate vertical adjustment function and being unsuitable for China, which has a complex climate and great undulating terrain. A new approach that considers the time-varying vertical adjustment and delicate diurnal variations of ZTD was introduced to develop a new grid ZTD model (NGZTD). The NGZTD model employed the Gaussian function and considered the seasonal variations of Gaussian coefficients to express the vertical variations of ZTD. The effectiveness of vertical interpolation for the vertical adjustment model (NGZTD-H) was validated. The root mean squared errors (RMSE) of the NGZTD-H model improved by 58% and 22% compared to the global pressure and temperature 3 (GPT3) model using ERA5 and radiosonde data, respectively. The NGZTD model’s effectiveness for directly estimating the ZTD was validated. The NGZTD model improved by 22% and 31% compared to the GPT3 model using GNSS-derived ZTD and layered ZTD at radiosonde stations, respectively. Seasonal variations in Gaussian coefficients need to be considered. Using constant Gaussian coefficients will generate large errors. The NGZTD model exhibited outstanding advantages in capturing diurnal variations and adapting to undulating terrain. We analyzed and discussed the main error sources of the NGZTD model using validation of spatial interpolation accuracy. This new ZTD model has potential applications in enhancing the reliability of navigation, positioning, and interferometric synthetic aperture radar (InSAR) measurements and is recommended to promote the development of space geodesy techniques.

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Section: Development Of the Ngztd-h Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A New Grid Zenith Tropospheric Delay Model Considering Time-Varying Vertical Adjustment and Diurnal Variation over China

Zhang,

Zuo,

Guo

et al. 2024

Remote Sensing

View full text Add to dashboard Cite

show abstract

“…Related scholars have used ECMWF or NCEP atmospheric reanalysis data to construct regional or global tropospheric delay models [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. Moreover, many Chinese scholars have constructed a wealth of regional or global tropospheric delay correction models using atmospheric reanalysis data [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. In addition, the use of atmospheric reanalysis data to improve the positioning accuracy and convergence efficiency of GNSS-PPP has also become an important topic [ 26 , 27 ].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the ZWD/ZTD Values Derived from MERRA-2 Global Reanalysis Products Using GNSS Observations and Radiosonde Data

Huang

Guo

Liu

et al. 2020

Sensors

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Tropospheric delay is one of the main errors affecting high-precision positioning and navigation and is a key parameter of water vapor detection in the Global Navigation Satellite System (GNSS). The second Modern-Era Retrospective analysis for Research and Applications (MERRA-2) is the latest generation of reanalysis data collected by the National Aeronautics and Space Administration (NASA), which can be used to calculate tropospheric delay products with high spatial and temporal resolution. However, there is no report analyzing the accuracy of the zenith tropospheric delay (ZTD) and zenith wet delay (ZWD) calculated from MERRA-2 data. This paper evaluates the performance of the ZTD and ZWD values derived from global MERRA-2 data using global radiosonde data and International GNSS Service (IGS) precise ZTD products. The results are as follows: (1) Taking the precision ZTD products of 316 IGS stations from around the world from 2015 to 2017 as the reference, the average root mean square (RMS) of the ZTD values calculated from the MERRA-2 data is better than 1.35 cm, and the accuracy difference between different years is small. The bias and RMS of the ZTD values show certain seasonal variations, with a higher accuracy in winter and a lower accuracy in summer, and the RMS decreases from the equator to the poles. However, those of the ZTD values do not show obvious variations according to elevation. (2) Relative to the radiosonde data, the RMS of the ZWD and ZTD values calculated from the MERRA-2 data are better than 1.37 cm and 1.45 cm, respectively. Furthermore, the bias and RMS of the ZWD and ZTD values also show some temporal and spatial characteristics, which are similar to the test results of the IGS stations. It is suggested that MERRA-2 data can be used for global tropospheric vertical profile model construction because of their high accuracy and good stability in the global calculation of the ZWD and ZTD.

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Real-time high-resolution tropospheric delay mapping based on GFS forecasts and GNSS

Lu,

Zhang,

Zheng

et al. 2024

GPS Solut

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An improved global zenith tropospheric delay model GZTD2 considering diurnal variations

Cited by 3 publications

References 7 publications

A New Grid Zenith Tropospheric Delay Model Considering Time-Varying Vertical Adjustment and Diurnal Variation over China

A New Grid Zenith Tropospheric Delay Model Considering Time-Varying Vertical Adjustment and Diurnal Variation over China

Evaluation of the ZWD/ZTD Values Derived from MERRA-2 Global Reanalysis Products Using GNSS Observations and Radiosonde Data

Real-time high-resolution tropospheric delay mapping based on GFS forecasts and GNSS

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