Coupling a weather model directly to GNSS orbit determination – case studies with OpenIFS
<p>Neutral gas atmosphere bends and delays propagation of microwave signals in satellite-based navigation. Weather prediction models can be used to estimate these effects by providing three-dimensional refraction fields to ray-trace the signal delays. In this study, a global numerical weather...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-04-01
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| Series: | Geoscientific Model Development |
| Online Access: | https://gmd.copernicus.org/articles/15/2763/2022/gmd-15-2763-2022.pdf |
| _version_ | 1819024976891609088 |
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| author | A. Navarro Trastoy S. Strasser L. Tuppi M. Vasiuta M. Poutanen T. Mayer-Gürr H. Järvinen |
| author_facet | A. Navarro Trastoy S. Strasser L. Tuppi M. Vasiuta M. Poutanen T. Mayer-Gürr H. Järvinen |
| author_sort | A. Navarro Trastoy |
| collection | DOAJ |
| description | <p>Neutral gas atmosphere bends and delays propagation of microwave signals in satellite-based navigation. Weather prediction models can be used to estimate these effects by providing three-dimensional refraction fields to ray-trace the signal delays. In this study, a global numerical weather prediction model (Open Integrated Forecasting System (OpenIFS) licensed for Academic use by the European Centre for Medium-Range Weather Forecast) is used to generate the refraction fields. The ray-traced slant delays are supplied as such – in contrast to mapping – for an orbit solver (GROOPS (Gravity Recovery Object Oriented Programming System) software toolkit of Graz University of Technology) which applies the raw observation method. Here we show that such a close coupling is possible without need for major additional modifications in the solver codes. The main finding here is that the adopted approach provides a very good a priori model for the atmospheric effects on navigation signals. We suspect that removal of the intermediate mapping step allows us to take advantage of the local refraction field asymmetries in the GNSS signal processing. Moreover, the direct coupling helps in identifying deficiencies in the slant delay computation because the modeling errors are not convoluted in the mapping procedures. These conclusions appear robust, despite the relatively small data set of raw code and phase observations covering the core network of 66 ground-based stations of the International GNSS Service over 1-month periods in December 2016 and June 2017. More generally, the new configuration enhances our control of geodetic and meteorological aspects of the orbit problem. This is pleasant because we can, for instance, regulate at will the weather model output frequency and increase coverage of spatiotemporal aspects of weather variations. The direct coupling of a weather model in precise GNSS orbit determination presented in this paper provides a unique framework for benefiting even more widely than previously the apparent synergies in space geodesy and meteorology.</p> |
| first_indexed | 2024-12-21T05:03:21Z |
| format | Article |
| id | doaj.art-afc42b1149ca479ea52fbb4f538ef251 |
| institution | Directory Open Access Journal |
| issn | 1991-959X 1991-9603 |
| language | English |
| last_indexed | 2024-12-21T05:03:21Z |
| publishDate | 2022-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Geoscientific Model Development |
| spelling | doaj.art-afc42b1149ca479ea52fbb4f538ef2512022-12-21T19:15:11ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032022-04-01152763277110.5194/gmd-15-2763-2022Coupling a weather model directly to GNSS orbit determination – case studies with OpenIFSA. Navarro Trastoy0S. Strasser1L. Tuppi2M. Vasiuta3M. Poutanen4T. Mayer-Gürr5H. Järvinen6Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, FinlandInstitute of Geodesy, Graz University of Technology, Graz, AustriaInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, FinlandInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, FinlandFinnish Geospatial Research Institute, National Land Survey of Finland, Espoo, FinlandInstitute of Geodesy, Graz University of Technology, Graz, AustriaInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland<p>Neutral gas atmosphere bends and delays propagation of microwave signals in satellite-based navigation. Weather prediction models can be used to estimate these effects by providing three-dimensional refraction fields to ray-trace the signal delays. In this study, a global numerical weather prediction model (Open Integrated Forecasting System (OpenIFS) licensed for Academic use by the European Centre for Medium-Range Weather Forecast) is used to generate the refraction fields. The ray-traced slant delays are supplied as such – in contrast to mapping – for an orbit solver (GROOPS (Gravity Recovery Object Oriented Programming System) software toolkit of Graz University of Technology) which applies the raw observation method. Here we show that such a close coupling is possible without need for major additional modifications in the solver codes. The main finding here is that the adopted approach provides a very good a priori model for the atmospheric effects on navigation signals. We suspect that removal of the intermediate mapping step allows us to take advantage of the local refraction field asymmetries in the GNSS signal processing. Moreover, the direct coupling helps in identifying deficiencies in the slant delay computation because the modeling errors are not convoluted in the mapping procedures. These conclusions appear robust, despite the relatively small data set of raw code and phase observations covering the core network of 66 ground-based stations of the International GNSS Service over 1-month periods in December 2016 and June 2017. More generally, the new configuration enhances our control of geodetic and meteorological aspects of the orbit problem. This is pleasant because we can, for instance, regulate at will the weather model output frequency and increase coverage of spatiotemporal aspects of weather variations. The direct coupling of a weather model in precise GNSS orbit determination presented in this paper provides a unique framework for benefiting even more widely than previously the apparent synergies in space geodesy and meteorology.</p>https://gmd.copernicus.org/articles/15/2763/2022/gmd-15-2763-2022.pdf |
| spellingShingle | A. Navarro Trastoy S. Strasser L. Tuppi M. Vasiuta M. Poutanen T. Mayer-Gürr H. Järvinen Coupling a weather model directly to GNSS orbit determination – case studies with OpenIFS Geoscientific Model Development |
| title | Coupling a weather model directly to GNSS orbit determination – case studies with OpenIFS |
| title_full | Coupling a weather model directly to GNSS orbit determination – case studies with OpenIFS |
| title_fullStr | Coupling a weather model directly to GNSS orbit determination – case studies with OpenIFS |
| title_full_unstemmed | Coupling a weather model directly to GNSS orbit determination – case studies with OpenIFS |
| title_short | Coupling a weather model directly to GNSS orbit determination – case studies with OpenIFS |
| title_sort | coupling a weather model directly to gnss orbit determination case studies with openifs |
| url | https://gmd.copernicus.org/articles/15/2763/2022/gmd-15-2763-2022.pdf |
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