Global Navigation Satellite Systems (GNSS)
GNSS allows users with compatible receiver devices to determine their position, velocity and local time by processing signals from satellites in point positions within space. GNSS signals are provided by satellite systems called core constellation systems. The current core constellation systems are USA’s Global Positioning System (GPS), Europe’s Galileo, Russia’s Global'naya Navigatsionnaya Sputnikovaya Sistema (GLONASS), and China’s Beidou. Technologies like Differential GNSS (DGNSS), Real-time Kinematics (RTK) and Precise Point Positioning (PPP) improve the accuracy of the core constellations while technologies such as Aircraft based Augmentation Systems (ABAS), Ground Based Augmentation Systems (GBAS) and Satellite Based Augmentation Systems (SBAS) in addition to improving accuracy provide integrity which is a measure of trust in the correctness of the information.
The use of GNSS Position, Navigation and Timing (PNT) information depends on operational requirements and encompasses different sectors from Aviation, Maritime, Road, Rail, Agriculture, consumer Location Based Services (LBS), and Geo-information to Timing and synchronization as well as Drones and Internet of Things (IoT) sectors.