A GNSS reference station is a stationary ground-based receiver that is used as a reference point for Global Navigation Satellite Systems (GNSS) such as GPS, GLONASS, Galileo, and BeiDou. It is typically placed at a known location with a clear view of the sky, and its precise coordinates are determined using a combination of satellite signals and other geodetic techniques.
The reference station continuously receives and records satellite signals, and it uses these signals to calculate precise measurements of the distance between itself and the satellites. These measurements are used to determine the exact location of the reference station, as well as to create a correction model that can be used to improve the accuracy of GNSS positioning for other users in the area.
GNSS reference stations are commonly used in surveying, geodesy, and other applications where high-precision positioning is required. They can also be used to provide real-time corrections to GPS signals, allowing for improved accuracy and reliability in a variety of applications, including navigation, mapping, and precision agriculture.