What is RTK GPS and how does it work?

RTK (Real-Time Kinematic) GPS is a high-precision technique achieving centimeter-level accuracy in real-time. A base station at known coordinates transmits carrier phase corrections via radio or cellular link to rover receiver. Rover combines corrections with its observations to compute precise position. Requires continuous communication and initialization (fixing integer ambiguities). Baseline should be <10-15 km for optimal accuracy. Network RTK uses multiple base stations for wider coverage. Applications: construction layout, machine guidance, cadastral surveys, and topographic mapping.