Fundamentals and History of Global Positioning
The Global Positioning System (GPS) is a satellite-based radionavigation system that provides accurate geolocation, velocity, and time synchronization worldwide, 24/7 in all weather conditions.
Originally initiated in the 1970s for defense and aerospace guidance, the civilian opening of high-precision signals turned GPS into the backbone of global logistics, maritime navigation, and vehicle telematics.
GPS is specifically the US satellite constellation. GNSS (Global Navigation Satellite System) encompasses GPS (USA), GLONASS (Russia), Galileo (Europe), and BeiDou (China). Multi-GNSS devices offer maximum coverage and reliability.
The Three Primary GPS Segments
GPS operations rely on the seamless coordination of three fundamental segments:
- Space Segment: 24 to 31 active satellites orbiting in 6 orbital planes at an altitude of approximately 20,200 km.
- Control Segment: Worldwide ground tracking stations, master control hubs, and antennas monitoring satellite health and clock calibrations.
- User Segment: Dedicated receivers, vehicle telematics units, and smartphones receiving satellite broadcast signals.
How Position is Calculated: Satellite Trilateration
A GPS tracker calculates its exact position by measuring the precise travel time of radio signals from at least 4 different satellites. Knowing the speed of light, the receiver computes distances and identifies the exact point where the spherical distance boundaries intersect.