The National Institute of Oceanography and Experimental Geophysics - OGS (Department of Experimental Seismology - CRS) and the Autonomous Region of Friuli Venezia Giulia are present in the Friuli Venezia Giulia region with two permanent GPS station networks: the FReDNet network (Friuli Regional Deformation Network) of OGS and the 'A. Marussi' Network of the FVG Region. Thanks to these infrastructures, the two entities provide two differential correction services for real-time positioning in the regional territory.

OGS, thanks to the data provided by the FReDNet network, aims to carry out activities of:

• Scientific research aimed at improving the geodynamic model of the regional area for the characterization of regional tectonic processes and some more critical areas from a seismic point of view. FReDNet must provide high-quality ground deformation data, and for this reason, the permanent sites of this network meet specific requirements of satellite constellation visibility, GPS antenna installation (usually on exposed rock) and geological;
• Applied research for the experimental, development, and distribution, on the regional territory, of real-time positioning services based on satellite GNSS technology (FReDNet supports GPS and GLONASS) according to the most common correction differential modes (RTK, MRS, and VRS).

The Friuli Venezia Giulia Region initiated the construction of the GPS Network 'A. Marussi' in 1997 to create a geodetic infrastructure capable of providing technological support to significant topographic and cadastral operations and the use of advanced systems in determining geographical elements to be automatically placed on regional cartography. The GPS Network has been an essential tool from the beginning for all regional and private technicians who, by competence, must carry out urgent and expedient topographic measurements or, more simply, locate significant elements for the management and planning of the territory. It is also fundamental in the realization and continuous updating of the Regional Technical Numeric Map.
Information about the network, services, and projects is available on the website: A. Marussi Network

The Friuli Venezia Giulia Region and OGS have signed, under Article 63 of Law Decree 27 December 1991, a convention for the non-profit exchange of cartographic and territorial data with public interest purposes. This Convention has been supplemented with an Additional Act in which the Entities commit to:

• Collaborate in the field of exchanging GPS/GNSS data recorded by their respective permanent GPS/GNSS networks, in maintaining the functionality of the networks and their services, and in improving the GPS/GNSS monitoring instrumental infrastructures managed by them;
• Define and implement a protocol for the real-time exchange of GPS/GNSS data (differential corrections) for the provision of real-time positioning services, according to GPS RTK and VRS modes, or equivalent, in the Friuli Venezia Giulia region territory;
• Collaborate to maintain or improve the positioning services already realized within the territorial area of the Friuli Venezia Giulia region, according to GPS-RTK and VRS modes, or equivalent.

To realize a GNSS positioning service, integrated on the regional territory, the calculation centers of the Friuli Venezia Giulia Region and OGS acquire and distribute on the internet, through the NTRIP protocol, all single base RTK differential corrections of both networks ('A. Marussi' and FReDNet). Network solutions, such as VRS and FKP, are instead generated and distributed separately by each calculation center based on the data of the network it belongs to..
In this way, reliable and efficient support is guaranteed to the users of the networks (redundancy of services and calculation and distribution servers and capillary coverage of the territory even with the service from a single station).

The real-time services provided by the FReDNet Network are distributed in relation to the new reference system ETRF2000(2008.0) adopted by the Italian Geographical Institute (IGM) for the framing of the National Dynamic Network (RDN).
This system will soon also be adopted in the real-time services distributed by the A. Marussi Network, although currently, the system in use is ETRF89, with the IGM95 network representing an improvement.

To access the real time service using the NTRip caster of FReDNet network you can use the following parameters:

Indirizzo Caster : 158.110.30.81
Porta : 2110
Username: Geo
Password: Geo

In addition to the mountpoints referring to the stations of the FReDNet Network, summarized on the RTK Service page, there are also the mountpoints listed below linked to the stations of the GPS "A Network. Marussi".