Evaluation of the impact of atmospheric pressure loading modeling on GNSS data analysis
In recent years, several studies have demonstrated the sensitivity of Global Navigation Satellite System (GNSS) station time series to displacements caused by atmospheric pressure loading (APL). Different methods to take the APL effect into account are used in these studies: applying the corrections from a geophysical model on weekly mean estimates of station coordinates, using observation-level corrections during data analysis, or solving for regression factors between the station displacement and the local pressure. The Center for Orbit Determination in Europe (CODE) is one of the global analysis centers of the International GNSS Service (IGS). The current quality of the IGS products urgently asks to consider this effect in the regular processing scheme. However, the resulting requirements for an APL model are demanding with respect to quality, latency, and—regarding the reprocessing activities—availability over a long time interval (at least from 1994 onward). The APL model of Petrov and Boy (J Geophys Res 109:B03405, 2004) is widely used within the VLBI community and is evaluated in this study with respect to these criteria. The reprocessing effort of CODE provides the basis for validating the APL model. The data set is used to solve for scaling factors for each station to evaluate the geophysical atmospheric non-tidal loading model. A consistent long-term validation of the model over 15 years, from 1994 to 2008, is thus possible. The time series of 15 years allows to study seasonal variations of the scaling factors using the dense GNSS tracking network of the IGS. By interpreting the scaling factors for the stations of the IGS network, the model by (2004) is shown to meet the expectations concerning the order of magnitude of the effect at individual stations within the uncertainty given by the GNSS data processing and within the limitations due to the model itself. The repeatability of station coordinates improves by 20% when applying the effect directly on the data analysis and by 10% when applying a post-processing correction to the resulting weekly coordinates compared with a solution without taking APL into account.
KeywordsAtmospheric pressure loading GNSS processing Model validation Terrestrial reference frame
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- Beutler G, Brockmann E, Gurtner W, Hugentobler U, Mervart L, Rothacher M, Verdun A (1994) Extended orbit modeling techniques at the CODE processing center of the International GPS Service for Geodynamics (IGS): theory and initial results. Manuscr Geodaetica 19(6): 367–386Google Scholar
- Dach R, Beutler G, Bock H, Fridez P, Gäde A, Hugentobler U, Jäggi A, Meindl M, Mervart L, Prange L, Schaer S, Springer T, Urschl C, Walser P (2007) Bernese GPS software version 5.0. Astronomical Institute, University of Bern, SwitzerlandGoogle Scholar
- Dach R, Springer T, Altamimi Z (2008) Experiment on impact of constrained orbit parameters on station coordinates. In: International GNSS Service: Analysis Center Workshop. Miami Beach, Florida, USAGoogle Scholar
- Manabe S, Sato T, Sakai S, Yokoyama K (1991) Atmospheric loading effect on VLBI observations. In: AGU Chapman conference on geodetic VLBI: monitoring global change. NOAA technical report NOS 137, NGS 49, U.S. Department of Commerce, NOAA/NOS, Rockville, MD, pp 111–122Google Scholar
- McCarthy D, Petit G (2004) IERS Conventions (2003). IERS technical note 32. Bundesamt für Kartographie und Geodäsie, Frankfurt am MainGoogle Scholar
- Ostini L, Dach R, Meindl M, Schaer S, Hugentobler U (2008) FODITS: a new tool of the Bernese GPS software. In: Ihde J, Hornik H (eds) EUREF symposium, no. 18, June 18–20, 2008, Brussels, Belgium. EUREF Publication (in print)Google Scholar
- Rabbel W, Zschau J (1985) Static deformations and gravity changes at the Earth’s surface due to atmospheric loading. J Geophys 56: 81–99Google Scholar
- Schaer S, Dach R, Meindl M (2008) CODE analysis strategy summary. http://www.aiub.unibe.ch/download/CODE/CODE.ACN
- Steigenberger P, Schaer S, Lutz S, Dach R, Ostini L, Hugentobler U, Bock H, Jäggi A, Meindl M, Thaller D (2009b) CODE. EGU General Assembly, Vienna, Austria, pp 19–24Google Scholar
- Tesmer V, Böhm J, Meisel B, Rothacher M, Steigenberger P (2008) Atmospheric loading coefficients determined from homogeneously reprocessed GPS and VLBI height time series. In: Finkelstein A Behrend D (eds) Measuring the future. Proceedings of the 5th IVS general meeting, pp 307–313Google Scholar
- van Dam T, Plag HP, Francis O, Gegout P (2003) GGFC special bureau for loading: current status and plans. In: Richter B, Schwegmann W, Dick WR (eds) Proceedings of the IERS workshop on combination research and global geophysical fluids. IERS technical note, no. 30. Verlag des Bundesamts für Kartographie und Geodäsie, Frankfurt am Main, pp 180–198Google Scholar