Improved Tropospheric Delay Estimation for Long Baseline, Carrier-Phase Differential GPS Positioning in a Coastal Environment

摘要

Long baseline, carrier-phase differential GPS positioning in a coastal environment poses unique challenges. It is well known that differential GPS positioning results degrade as baseline length increases due to several sources of error, including the error introduced by differential troposphere. The effect of the troposphere on GPS has been extensively discussed by numerous researchers, either by comparing the resolution of tropospheric prediction models or by assessing the tropospheric delay directly on GPS measurements and results. rnIn order to improve the estimation of tropospheric delay in the coastal environment, a project has been undertaken by the University of New Brunswick (UNB) and the University of Southern Mississippi (USM). The project includes extensive GPS and meteorological data collection in the Bay of Fundy in Canada. The goal of the research is to examine methods for improving tropospheric delay estimation by employing various sources of data. This includes the use of surface meteorological parameters and Numerical Weather Prediction (NWP) model data. For this research, NWP data are accessed from the Canadian Meteorological Centre’s (CMC) regional model and from the National Oceanic and Atmospheric Administration’s (NOAA) tropospheric delay product. Tropospheric delays modelled from the NWP model data are compared with those from global prediction models. Results in this paper will demonstrate the effect of using surface meteorological data and NWP model data to estimate the tropospheric delay in a coastal environment.