Adjustment and transformation strategies of ItalPoS permanent GNSS network

A private network of 133 Global Navigation Satellite Systems (GNSS) permanent sites, named ItalPoS (Italian Positioning Service) and covering quite uniformly the entire Italian territory, was established since April 2006 by the Italian Division of Leica Geosystems S.p.A. This network involves also several GPS stations of the INGV (Italian National Institute of Geophysics and Volcanology) RING (Real-time Integrated National Gps) network and GPS stations from other public and private administrations. Indeed Leica Geosystems contributed with its experience and its products to these networks which nowadays fulfill the national covering where there are no ItalPoS stations. For instance, the purpose of ItalPoS network is mainly the GNSS data distribution in terms of real time corrections and RINEX files for the post-processing.In order to compute and distribute to private and scientific users a set of adjusted coordinates of the ItalPoS network in the IGS05 and ETRF89-2000 reference frames, a dataset of RINEX of about 120 GPS permanent sites was created and processed, using the distributed sessions approach, by means of Gamit/Globk 10.3 GPS data processor, using also some SOPAC (Scripps Orbits and Permanent Array Center) and EUREF (European Permanent Network) solutions to improve the reference frame definition and the internal constraint.In this paper we describe all the strategies adopted to estimate coordinates and velocities of the ItalPoS Network in IGS05 and in ETRF89-2000 reference frames in the whole Italian territory.