Data Analysis of Permanent GPS Sites (RING) in Italy

The RING (Rete Integrata Nazionale GPS) GPS network is the result of a scientific project started by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) in 2004 with the aim of increasing the number of continuous GPS stations (CGPS) in Italy in order to improve the knowledge of the geodynamics and tectonic processes acting in this area which is characterized by a complex set of independent or partially independent crustal blocks, within the slowly converging African and Eurasian plates. At present RING is a dense CGPS network of more than 110 stations covering the Italian area and integrating GPS receivers with broad-band seismometers and accelerometers in real time connection with three acquisition centers. In this work we describe the data analysis strategy of the whole GPS network (consisting of RING sites, other public Italian CGPS and some IGS sites for a total amount of about 300 stations) and some results in terms of position time series and velocities. The processing is performed adopting a distributed session approach, with more than 10 clusters, sharing common stations, each of them consisting of about 40 stations. Daily loosely constrained solutions are routinely produced for each cluster using the Bernese and Gamit softwares and then transformed into the ITRF05 reference frame. In the next months these solutions will be freely available as daily SINEX files on the public RING website http://ring.gm.ingv.it and subsequently other derived geodetic products (full time series, velocity field, etc.) will also be available.