Network RTK requires a recommended minimum of five reference stations (there is no maximum) with an inter-station spacing of up to 70 km.
The reference stations are usually permanent installations and form the RTK Network , which is the backbone of the Network RTK principle.
The principle of Network RTK begins with all reference stations within the RTK Network continuously streaming satellite observations to a central server running Network RTK software, such as Leica GNSS Spider.
The aim of Network RTK is to minimise the influence of the distance dependant errors on the rovers computed position within the bounds of the network. The Network RTK server software begins this process by:
Figure 3: Principle of Network RTK
The advantages of Network RTK are:
The disavantage of Network RTK is:
This decrease in accuracy is due to distance dependant errors - mainly atmospheric errors. Essentially, as the distance between the rover and the reference station increases, the atmospheric conditions at the rover and reference station will become increasingly different. This decreases the accuracy and makes it more difficult for the rover to fix the ambiguities.