Real-Time Kinematic (RTK) is a precise positioning technology used in global navigation satellite systems (GNSS) to achieve highly accurate location data, typically within centimeters. RTK enhances standard GNSS accuracy by using a fixed base station and a mobile rover unit. The base station calculates errors in satellite signals caused by atmospheric and other factors and transmits corrections to the rover in real time. This process allows the rover to adjust its position calculations dynamically, ensuring a higher degree of accuracy. RTK is commonly employed in applications such as land surveying, agriculture, construction, and autonomous vehicles, where precise positioning is critical. It relies on robust data communication between the base station and rover, typically through radio signals, cellular networks, or the internet.
How RTK works step-by-step
- GNSS Signal Reception: Both a stationary base station and a mobile rover receive signals from multiple GNSS satellites. These signals include information about the satellites’ positions and the time the signals were transmitted.
- Base Station Positioning: The base station is set up at a fixed, known location. Since its position is already known, it can calculate the errors in the satellite signals it receives, such as errors due to atmospheric delays, clock inaccuracies, or orbital deviations.
- Error Calculation: By comparing the received satellite signal data to its known position, the base station determines the amount of error present in the positioning data.
- Error Correction Transmission: The base station transmits these error corrections to the rover unit in real time. This communication is usually done via radio waves, cellular networks, or the internet.
- Rover Adjustment: The rover, which is in motion, applies the corrections received from the base station to its own GNSS data. This process significantly reduces errors, allowing the rover to calculate its position with centimeter-level accuracy.
- Real-Time Updates: The process of receiving satellite data, calculating errors, and applying corrections happens continuously and in real time, ensuring that the rover maintains high accuracy even while moving.
