Depending on the range to the nearest reference station (< 40 km), position accuracies of within a centimeter can be achieved using Network RTK.
The VBOX NTRIP Modem enables the roving VBOX unit to send its position to the stations within the network – just as it would to a single VBOX Base Station. The NTRIP service provider will then calculate the appropriate corrections for the VBOX’s location based on the data from nearby reference stations. This correction information is then returned to the VBOX in the same RTCM format as is used for a single fixed base station.
In order to use this type of correction you have to register and subscribe to a cellular data plan with your local NTRIP provider, such as Topnet in the UK and Germany, Swepos in Sweden or Unavco in the USA.
Network RTK utilises one or more Continuous Operating Reference Stations (CORS) to provide RTK data to a GNSS Rover, usually via mobile internet. The most common method of Network RTK involves a two-way communication link which allows the roving vehicle to send its position to a service provider that is monitoring satellite observations from several reference stations around a country.