Tropospheric Refraction Estimation Using Various Models, Radiosonde Measurements and Permanent GPS Data, paper presented at XXIII FIG

The basic idea of this study is the estimation of Tropospheric delay with all of possible observations and methods available in the surround area of EUREF GPS station (AUT1) of the Aristotle University of Thessaloniki. The tropospheric delay is estimated in situ from three different data sources. We estimate the tropospheric delay using 3 days of GPS pseudorange observations (days 157, 158, 159 in 2005), and the Total Zenith delay derived from the EUREF analysis centre. We compare the estimated delay from the permanent GPS data with that measured from radiosonde measurements which carried out at Thessaloniki airport, located near to GPS station. In addition, the tropospheric delay is estimated using three known tropospheric models, Ifadis, Niell and Saastamoinen. The tropospheric delay from Ifadis and Niell models is computed using the corresponding mapping functions with the calculated Total Zenith delay from radiosonde data. In Saastamoinen model surface meteorological data was used. PS5.4 – GNSS Processing and Application