New ways to Network RTK: How do VRS and MAC measure up?

The concept of Network Real Time Kinematic observations was introduced in the mid-1990s. It has been progressively developed into the commercially viable systems available now. Conventional single-base RTK is limited to distances of 10-20 kilometres from the base station. Long-range RTK made it possible to observe baselines of up to about 50 kilometres. However, by using the information from a network of continuously operating reference stations, highly accurate positioning is now achievable over distances of several tens of kilometres. This article compares the two most prevalent methods, the Virtual Reference Station (VRS) approach and the Master- Auxiliary Concept (MAC).