GPSRTK

GPS Real-Time Kinematic (GPS-RTK) is a GNSS positioning technique that delivers centimeter-level accuracy by applying real-time carrier-phase corrections to a rover’s GPS observations. It relies on a base station with a precisely known position to compute corrections and transmit them to rovers in real time.

In operation, the base collects GNSS data and generates corrections, which are sent via radio, cellular, or Internet links. The rover uses these corrections with its own raw observations, employing differential processing that often includes double-difference calculations and integer ambiguity resolution to determine a precise position as measurements are gathered.

RTK systems commonly use RTCM-formatted corrections and can operate as a single-base setup or as part of a network. Network RTK (NRTK) utilizes multiple reference stations to provide corrections over a wide area, improving reliability and reducing distance- and atmosphere-related errors. Some approaches are moving toward PPP-RTK, which relies on precise satellite clock and orbit models to provide real-time positioning with reduced or no local base infrastructure.

Accuracy varies with conditions but is typically in the range of 1–3 centimeters horizontally and a few centimeters vertically under favorable conditions. Performance depends on baseline length, satellite geometry, atmospheric effects, multipath, and the reliability of the communication link between base and rover.

Applications include land surveying, construction and civil engineering, precise mapping, agriculture, mining, and autonomous navigation. GPS-RTK remains a foundational technique for tasks requiring real-time, high-precision positioning.