These uses are collectively known as Positioning, Navigation and Timing (PNT). The signals also allow the electronic receiver to calculate the current local time to high precision, which allows time synchronisation. The system can be used for providing position, navigation or for tracking the position of something fitted with a receiver (satellite tracking). It allows small electronic receivers to determine their location ( longitude, latitude, and altitude/ elevation) to high precision (within a few centimeters to metres) using time signals transmitted along a line of sight by radio from satellites. A satellite navigation or satnav system is a system that uses satellites to provide autonomous geo-spatial positioning.
