ABSTRACT
The use of Global Navigation Satellite Systems (GNSS) for positioning has revolutionized the way location data is being
collected. The NAVigation System with Time And Ranging Global Positioning System (GPS), which is a principal
component of the global navigation satellite system (GNSS); is a satellite-based radio navigation system that provides
positions of points of interest and time information to users. GPS positional accuracy can be improved by using differential
corrections obtained through a technique called Differential GPS (DGPS), which is known to provide the most
accurate positioning results. Differential correction can be applied in real time at the data collection phase or in the office,
at the post-processing phase. DGPS is generally used for positioning purposes through static or kinematics GPS
surveys. In static GPS surveys, one receiver is placed at a point whose coordinates are known and the other receiver is
placed over a point whose coordinates are desired. In kinematic surveys, one receiver remains at one point (base station)
normally with known coordinates, and the other receiver (rover) moves from point to point in the project area. Kinematic
surveys in which points positions are computed on-the-fly (OTF) are known as real-time kinematic (RTK). RTK
surveys provide real-time locations of points of interest needed in many applications. Positioning with wide-area GNSS
networks is basically based on the DGPS and RTK concepts. Observables from a network of a finite number of GPS
receivers over an area are processed by a server at a central location (network server) and made available to the users of
the network later or in real-time through radio-based, satellite, or wireless communications. This article provides a review
of the concept and application of positioning with wide-area GNSS networks.