The impact of mapping functions for the neutral atmosphere based on numerical weather models in GPS data analysis

Abstract

Since troposphere modelling is one of the major error sources in the geodetic applications of Global Positioning System (GPS) and Very Long Baseline Interferometry observations, mapping functions have been developed in the last years which are based on data from numerical weather models. This paper presents the first results with the Vienna Mapping Functions 1 (VMF1) implemented in a GPS software package (GAMIT/GLOBK). The analysis of a global GPS network from July 2004 until July 2005 with VMF1 and the Niell Mapping Functions (NMF) shows that station heights can change by more than 10 mm, in particular from December to January in the Antarctic, Japan, the northern part of Europe and the western part of Canada, and Alaska. The application of the VMF1 (instead of NMF) also improves the repeatability of the geodetic results and reduces seasonal signals in the station height time series.