Atmospheric gradients estimated by GPS compared to a high resolution numerical weather prediction (NWP) model

Citation
A. Walpersdorf et al., Atmospheric gradients estimated by GPS compared to a high resolution numerical weather prediction (NWP) model, PHYS CH P A, 26(3), 2001, pp. 147-152
Citations number
14
Categorie Soggetti
Earth Sciences
Journal title
PHYSICS AND CHEMISTRY OF THE EARTH PART A-SOLID EARTH AND GEODESY
ISSN journal
14641895 → ACNP
Volume
26
Issue
3
Year of publication
2001
Pages
147 - 152
Database
ISI
SICI code
1464-1895(2001)26:3<147:AGEBGC>2.0.ZU;2-G
Abstract
The estimation of horizontal atmospheric gradients, in addition to zenith d elays, is a strategy now commonly used in geodetic Global Positioning Syste m (GPS) positioning. This strategy compensates for inhomogeneities in the a tmospheric water vapor distribution above GPS sites, and has shown to incre ase the positioning precision, e.g. in geodynamic networks. While the zenit h delay has been successfully related to the pressure at the GPS site and t he water vapor above the site, the relation of the GPS estimated horizontal gradients to atmospheric quantities remains unclear. To get a better under standing of the nature of these gradients inferred by GPS, this study compa res GPS tropospheric observations from the MAGIC permanent network on the N W side of the Mediterranean Sea with simulations based on the high resoluti on NWP model ALADIN (Meteo France). To verify the model performance, we use meteorological measurements from the FETCH ship campaign in the Gulf of Ly on in March-April 1998. For this study, five stations of the MAGIC network close to the Golf of Lyon have been selected. Results from two periods, rep resenting two different weather situations occuring within the FETCH observ ation campaign, are presented. (C) 2001 Elsevier Science Ltd. All rights re served.