Single baseline GLONASS observations with VLBI: data processing and first results

The VLBI technique, in geodetic mode, was used to observe signals emitted by three GLONASS (GLObal NAvigation Satellite System) satellites. The baseline observing simultaneously satellites had at its ends the Medicina (32 m) and Onsala85 (25 m) radio telescopes, both equipped with L-band receivers. Several preparatory tests were necessary for obtaining good data that could be processed. In this paper we report on the observations performed on August 16, 2010 data processing and results of the experiment. The natural radio source 3c286 was observed also as a calibrator before and after satellite observing sessions. A narrow band approach using software primarily developed for astronomical and space applications, was applied to extract the narrow band carrier. Differential frequency on the baseline Medicina-Onsala was also evaluated to compute differential phase which was then adopted to determine satellite coordinate corrections with respect to ITRF values. Broad-band correlation was performed on the calibrator data using the DiFX software. The SFXC correlation of satellite data was performed testing near field delay model at extreme nearness; obtained results are described.