Assessment of GNSS zenith tropospheric delay responses to atmospheric variables derived from ERA5 data over Nigeria
Abstract Tropospheric delay is a major error caused by atmospheric refraction in Global Navigation Satellite System (GNSS) positioning. The study evaluates the potential of the European Centre for Medium-range Weather Forecast (ECMWF) Reanalysis 5 (ERA5) atmospheric variables in estimating the Zenit...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2023-05-01
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| Series: | Satellite Navigation |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s43020-023-00104-7 |
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| author | Ifechukwu Ugochukwu Nzelibe Herbert Tata Timothy Oluwadare Idowu |
| author_facet | Ifechukwu Ugochukwu Nzelibe Herbert Tata Timothy Oluwadare Idowu |
| author_sort | Ifechukwu Ugochukwu Nzelibe |
| collection | DOAJ |
| description | Abstract Tropospheric delay is a major error caused by atmospheric refraction in Global Navigation Satellite System (GNSS) positioning. The study evaluates the potential of the European Centre for Medium-range Weather Forecast (ECMWF) Reanalysis 5 (ERA5) atmospheric variables in estimating the Zenith Tropospheric Delay (ZTD). Linear regression models (LRM) are applied to estimate ZTD with the ERA5 atmospheric variables. The ZTD are also estimated using standard ZTD models based on ERA5 and Global Pressure and Temperature 3 (GPT3) atmospheric variables. These ZTD estimates are evaluated using the data collected from the permanent GNSS continuously operating reference stations in the Nigerian region. The results reveal that the Zenith Hydrostatic Delay (ZHD) from the LRM and the Saastamoinien model using ERA5 surface pressure are of identical accuracy, having a Root Mean Square (RMS) error of 2.3 mm while the GPT3-ZHD has an RMS of 3.4 mm. For the Zenith Wet Delay (ZWD) component, the best estimates are derived using ERA5 Precipitable Water Vapour (PWV). These include the ZWD derived by the LRM having an average RMS of 20.9 mm and Bevis equation having RMS of 21.1 mm and 21.0 mm for global and local weighted mean temperatures, respectively. The evaluation of GPT3-ZWD estimates gives RMS of 45.8 mm. This study has provided a valuable insight into the application of ERA5 data for ZTD estimation. In line with the findings of the study, the ERA5 atmospheric variables are recommended for improving the accuracy in ZTD estimation, required for GNSS positioning. |
| first_indexed | 2024-03-13T07:20:17Z |
| format | Article |
| id | doaj.art-91d868fabe2a4b22b4892749aaef814f |
| institution | Directory Open Access Journal |
| issn | 2662-9291 2662-1363 |
| language | English |
| last_indexed | 2024-03-13T07:20:17Z |
| publishDate | 2023-05-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Satellite Navigation |
| spelling | doaj.art-91d868fabe2a4b22b4892749aaef814f2023-06-04T11:41:19ZengSpringerOpenSatellite Navigation2662-92912662-13632023-05-014111610.1186/s43020-023-00104-7Assessment of GNSS zenith tropospheric delay responses to atmospheric variables derived from ERA5 data over NigeriaIfechukwu Ugochukwu Nzelibe0Herbert Tata1Timothy Oluwadare Idowu2Department of Surveying and Geoinformatics, Federal University of Technology AkureDepartment of Surveying and Geoinformatics, Federal University of Technology AkureDepartment of Surveying and Geoinformatics, Federal University of Technology AkureAbstract Tropospheric delay is a major error caused by atmospheric refraction in Global Navigation Satellite System (GNSS) positioning. The study evaluates the potential of the European Centre for Medium-range Weather Forecast (ECMWF) Reanalysis 5 (ERA5) atmospheric variables in estimating the Zenith Tropospheric Delay (ZTD). Linear regression models (LRM) are applied to estimate ZTD with the ERA5 atmospheric variables. The ZTD are also estimated using standard ZTD models based on ERA5 and Global Pressure and Temperature 3 (GPT3) atmospheric variables. These ZTD estimates are evaluated using the data collected from the permanent GNSS continuously operating reference stations in the Nigerian region. The results reveal that the Zenith Hydrostatic Delay (ZHD) from the LRM and the Saastamoinien model using ERA5 surface pressure are of identical accuracy, having a Root Mean Square (RMS) error of 2.3 mm while the GPT3-ZHD has an RMS of 3.4 mm. For the Zenith Wet Delay (ZWD) component, the best estimates are derived using ERA5 Precipitable Water Vapour (PWV). These include the ZWD derived by the LRM having an average RMS of 20.9 mm and Bevis equation having RMS of 21.1 mm and 21.0 mm for global and local weighted mean temperatures, respectively. The evaluation of GPT3-ZWD estimates gives RMS of 45.8 mm. This study has provided a valuable insight into the application of ERA5 data for ZTD estimation. In line with the findings of the study, the ERA5 atmospheric variables are recommended for improving the accuracy in ZTD estimation, required for GNSS positioning.https://doi.org/10.1186/s43020-023-00104-7ECMWF reanalysis 5 (ERA5)Global navigation satellite systems (GNSS)Global pressure and temperature 3 (GPT3)ModellingNigeriaZenith tropospheric delay (ZTD) |
| spellingShingle | Ifechukwu Ugochukwu Nzelibe Herbert Tata Timothy Oluwadare Idowu Assessment of GNSS zenith tropospheric delay responses to atmospheric variables derived from ERA5 data over Nigeria Satellite Navigation ECMWF reanalysis 5 (ERA5) Global navigation satellite systems (GNSS) Global pressure and temperature 3 (GPT3) Modelling Nigeria Zenith tropospheric delay (ZTD) |
| title | Assessment of GNSS zenith tropospheric delay responses to atmospheric variables derived from ERA5 data over Nigeria |
| title_full | Assessment of GNSS zenith tropospheric delay responses to atmospheric variables derived from ERA5 data over Nigeria |
| title_fullStr | Assessment of GNSS zenith tropospheric delay responses to atmospheric variables derived from ERA5 data over Nigeria |
| title_full_unstemmed | Assessment of GNSS zenith tropospheric delay responses to atmospheric variables derived from ERA5 data over Nigeria |
| title_short | Assessment of GNSS zenith tropospheric delay responses to atmospheric variables derived from ERA5 data over Nigeria |
| title_sort | assessment of gnss zenith tropospheric delay responses to atmospheric variables derived from era5 data over nigeria |
| topic | ECMWF reanalysis 5 (ERA5) Global navigation satellite systems (GNSS) Global pressure and temperature 3 (GPT3) Modelling Nigeria Zenith tropospheric delay (ZTD) |
| url | https://doi.org/10.1186/s43020-023-00104-7 |
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