RTK dictionary / breakdown of terms specific to RTK / GNSS configuration

This RTK/GNSS terminology dictionary is designed to demystify the jargon and provide clear, concise definitions of key terms and concepts used in RTK and GNSS configurations. Whether you are a professional surveyor, a student, or just someone with an interest in satellite navigation systems, this dictionary will serve as a valuable resource for understanding the intricate details of RTK and GNSS technologies.

  • Base Station/Reference Station: A fixed GNSS receiver that is used as a reference station for RTK and DGNSS applications. The base station calculates corrections that are transmitted to the mobile rover to improve the accuracy of the position data.
  • Mobile Rover: A GNSS receiver that is used to collect position data in the field. The rover receives corrections from the base station to improve the accuracy of the position data.
  • Multipath: A phenomenon that occurs when GNSS signals are reflected off surfaces such as buildings, trees, and other obstacles before reaching the receiver. Multipaths can cause errors in the position data and is a common source of error in GNSS measurements.
  • Carrier Phase: The measurement of the phase of the GNSS signal carrier wave. Carrier phase measurements are used in RTK and PPP applications to improve the accuracy of the position data.
  • Satellite Ephemeris: The information that describes the position and velocity of a satellite in orbit. Satellite ephemeris data is used by GNSS receivers to calculate the position of the receiver on the ground.
  • Geoid: The equipotential surface of the Earth’s gravity field that best fits mean sea level. The geoid is used as a reference surface for height measurements in GNSS applications.
  • RINEX (Receiver Independent Exchange Format): A file format used to exchange GNSS data between different software and hardware platforms. RINEX files contain raw GNSS measurements, satellite ephemeris data, and other information.
  • Float Solution: A GNSS positioning solution that provides a position estimate based on the raw GNSS measurements without using correction data. Float solutions typically have lower accuracy than RTK solutions.
  • Fixed Solution: A GNSS positioning solution that provides a highly accurate position estimate based on the raw GNSS measurements and correction data received from the base station. Fixed solutions are typically used in RTK applications.
  • Ambiguity: The integer number of carrier cycles between the GNSS receiver and the satellite. Ambiguity resolution is the process of determining the correct integer number of carrier cycles to improve the accuracy of the position estimate.
  • Baseline: The distance between the base station and the mobile rover in RTK applications. The baseline length affects the accuracy of the RTK solution.
  • RTCM (Radio Technical Commission for Maritime Services): A standard format used to transmit correction data in RTK and DGNSS applications. RTCM messages contain information about satellite positions, atmospheric conditions, and other factors that affect the accuracy of GNSS measurements.
  • SNR (Signal-to-Noise Ratio): The ratio of the signal power to the noise power in a GNSS measurement. SNR is used as a measure of the quality of the GNSS signal and affects the accuracy of the position estimate.
  • Multipath Mitigation: Techniques used to reduce the effects of multipath on GNSS measurements. Multipath mitigation techniques include antenna design, signal processing algorithms, and the use of multiple frequencies.