Achievable Positioning Accuracies in a Network of GNSS Reference Stations - Global Navigation Satellite Systems: Signal,Theory and Applications - page 197

The experiments were conducted using, as rover site, the reference one located on the roof
of the headquarters of the Politecnico di Torino at Vercelli. For this reason, other reference
stations have been chosen in the north-west side of Italy, so that the rover can be in a
centroid point with respect to the three different GNSS networks (Fig. 4). The reference
stations that are involved in this test (see the Table 1) belong to networks operated by public
entities (such as administrative regions) and by private organizations (for example Surveyor
Colleges or private companies).

Station
ID

Station
Name

Receiver type
(IGS name)

Antenna type
(IGS name)

ALES Alessandria LEICA GRX1200+GNSS LEIAR25.R3

CRES Crescentino LEICA GRX1200+GNSS LEIAR25.R3

BIEL Biella LEICA GRX1200+GNSS LEIAR25.R3

LENT Lenta TPS NETG3 TPSCR.G3

VIGE Vigevano TPS ODYSSEY_E TPSCR3_GGD

TORI Torino LEICA GRX1200+GNSS LEIAR25.R3

CHAT Chatillon TPS NETG3 TPSCR.G3

LUIN Luino TPS NETG3 TPSG3_A1

CREA Crema TPS ODYSSEY_E TPSCR3_GGD

SESC Serravalle Scrivia TPS NETG3 TPSCR.G3

CARP Carpenedolo LEICA GRX1200+GNSS LEIAS10

BUSL Bussoleno LEICA GRX1200+GNSS LEIAR25.R3

LOAN Loano TPS NETG3 TPSCR.G3

TARO Borgo val di Taro TPS ODYSSEY_E TPSCR3_GGD

DOMO Domodossola TPS NETG3 TPSCR.G3

Table 1. Characteristics of permanent stations

The reference coordinates of all the stations were computed by processing 15 days of data
with the Bernese GPS scientific software (version 5.0), linking the networks reference system
with the ETRF2000 (2008.0), that is the Italian reference system materialized by the RDN.
The different antennas used for the rover receivers were mounted on a pillar, as mentioned
above, located on the roof of the Politecnico di Torino at Vercelli (Fig. 2).

The network software that was used is GNSMART (GNSS State Monitoring and
Representation Technique), distributed by Geo++®. This software allows to quantify and to
estimate tropospheric and ionospheric errors in addition to allows the modelling of the
satellites ephemeris errors, of the multipath estimation and of the satellite and receiver clock
errors. Even if it has no theoretical limitations to the minimum number of permanent
stations, for a correct functioning, at least 5 stations are suggested.

In the experiments, double frequency, geodetic GNSS receivers of the main companies
operating in Italy were used. The characteristics of the instruments are shown in the Table 2.