DGNSS and RTK - Positioning by Means of Correction Data

For a lot of applications the accuracy which can be achieved by stand-alone satellite-based positioning is not enough. For these applications there are methods of reducing deviations.

Reference Stations

A GNSS-receiver is used as a reference on a precisely defined coordinate. The current local deviations which occur when measuring the distance to the respective satellite is determined by means of the receiver. This information is transmitted to the rover (mobile GNSS receiver). Now the rover is able to carry out positionings with a much higher accuracy. This improvement of accuracy decreases when the signal delay and the spatial distance increases.


Differential GNSS (DGNSS) corrects code measurements which improves the accuracy by 50 cm to 1 metre, depending on the precision of the reference stations and the rover hardware in use. Real-time kinematic (RTK) corrects the significantly more precise phase measurement procedure. The result is an accuracy of 2 cm.

RTK-systems have a high performance RTK-algorithms and fast processors, process code measurements and phase measurement procedures and should be able to track at least two frequencies. The availability of RTK solutions depends very much on the number of satellites one can work with. Therefore, to increase the quantity of satellites, modern RTK-systems support GPS and GLONASS, as well as GALILEO in the future.