contenuti
The use of real-time differential correction is the most convenient and productive method for
operating GPS\GNSS surveys, as it allows the accuracy of measurements to be quickly and directly
improved in the field.
The real-time positioning service provided by the FVG network distributes differential
corrections both of code for navigation with a precision of metres (DGPS) and of phase for
positioning with a precision of a few centimetres (RTK). The differential corrections are available
both from the network and referred to the single master station.
The network solutions are built with the following systems:
- VRS (Virtual Reference Station): the user sends the control centre their approximate location. Based on the data of the surrounding permanent stations, the network generates a virtual station next to the rover and sends them a personalised correction.
- MAC (Master Auxiliary Concept): the network processing consists of estimating the differences between the data of one station (Master) and those of the others (Auxiliary), reducing all the observations to the same level of overall ambiguity. The information is packaged compactly and sent to the receiver rover without performing any spatial modelling. The user can choose the most appropriate manner to process the data received. The MAC mode requires the use of RTCM format in version 3.0 and later.
- I-MAC (Individualised MAC): is a method similar to VRS, but the corrections are referred to a real, non-virtual station.
- Nearest: the user is sent the correction coming from the nearest permanent station to the rover.
The characteristics of the differential corrections of the distributed network are summarised in the following table:
Mountpoint | Tipo di Soluzione | Formato |
---|---|---|
SingleBase_RTCM23 | Nearest – RTK | RTCM 2.3 |
SingleBase_RTCM31 | Nearest – RTK | RTCM 3.0 |
VRS_RTCM23 | VRS – RTK | RTCM 2.3 |
VRS_RTCM31 | VRS – RTK | RTCM 3.1 |
VRS_CMR | VRS – RTK | CMR |
MAC_RTCM31 | MAC – RTK | RTCM 3.1 |
IMAC_RTCM3 | IMAC – RTK | RTCM 3.1 |
All the mountpoints listed above require the rover receiver to send an NMEA string (GGA
position) to identify its position. The “SingleBase” mountpoints do not provide a network solution
but are able, through the NMEA string provided by the rover, to pinpoint its position and transmit
the differential correction referred to the nearest permanent station (Nearest) to the rover at
that moment.
The mountpoints listed below refer to the single permanent stations, and provide solutions
for both DGPS and RTK: :
Mountpoint | Tipo di Soluzione | Formato |
Ampezzo_DGPS | Singola Base – DGPS | RTCM 2.1 |
Ampezzo_RTK | Singola Base – RTK | RTCM 2.3 |
Bevazzana_DGPS | Singola Base – DGPS | RTCM 2.1 |
Bevazzana _RTK | Singola Base – RTK | RTCM 2.3 |
Barcis_DGPS | Singola Base – DGPS | RTCM 2.1 |
Barcis _RTK | Singola Base – RTK | RTCM 2.3 |
Cervignano_DGPS | Singola Base – DGPS | RTCM 2.1 |
Cervignano_RTK | Singola Base – RTK | RTCM 2.3 |
Gorizia_DGPS | Singola Base – DGPS | RTCM 2.1 |
Gorizia _RTK | Singola Base – RTK | RTCM 2.3 |
Pordenone_DGPS | Singola Base – DGPS | RTCM 2.1 |
Pordenone _RTK | Singola Base – RTK | RTCM 2.3 |
MoggioUdinese_DGPS | Singola Base – DGPS | RTCM 2.1 |
MoggioUdinese_RTK | Singola Base – RTK | RTCM 2.3 |
Tarvisio_DGPS | Singola Base – DGPS | RTCM 2.1 |
Tarvisio_RTK | Singola Base – RTK | RTCM 2.3 |
Trieste_DGPS | Singola Base – DGPS | RTCM 2.1 |
Trieste_RTK | Singola Base – RTK | RTCM 2.3 |
Udine_DGPS | Singola Base – DGPS | RTCM 2.1 |
Udine_RTK | Singola Base – RTK | RTCM 2.3 |
Access to real-time positioning is realised via internet through an Ntrip caster (Networked
Transport of RTCM via Internet Protocol) accessible at
http://gnsscaster.regione.fvg.it:8080 or
http://193.43.178.173:8080
Access to the real-time service is free, but is regulated through access credentials (username and password) that can be requested by emailing the duly completed application form, which can be downloaded from the Forms section of this site.
It is advisable to refer to the operation manual of your rover or to your dealer, for the
correct configuration of your receiver for the utilisation of differential corrections in real time
via Ntrip.
Ntrip account request form
The form should be sent to the following e-mail:
rete.gnss.marussi@regione.fvg.it
Access to the archive of the "historical data" network "A. Marussi" (when available) can be done by written and reasoned request by e-mail to rete.gnss.marussi@regione.fvg.it and depending on the load the work of the relevant departments.
It is hoped that there will be active collaboration with neighbouring operators of similar networks in the search for an ever better satisfaction of the expectations of respective users, for the harmonious and peaceful development of our communities.
-
Module
Il modulo va spedito alla seguente e-mail: rete.gnss.marussi@regione.fvg.it