Real-Time Kinematic (RTK)

A carrier-phase GNSS technique that resolves the integer cycle ambiguity to deliver centimeter-level positioning, typically 1 to 2 cm horizontal, by differencing a rover against a base station with a known position over a data link. Unlike code-phase DGNSS, which gives meter accuracy, RTK uses the carrier wavelength (about 19 cm on GPS L1) for far finer resolution but needs a short baseline and a correction stream (often RTCM 3.x). In ports it drives automated container handling, dredging, and pilot portable units for parallel berthing; PPK is its post-processed variant.