GPS, or Global Positioning System, is a satellite-based navigation system that allows you to determine your exact location anywhere on Earth. It works by using a network of satellites orbiting our planet, constantly transmitting signals to GPS receivers on the ground.
Each GPS satellite continuously broadcasts radio signals that contain three critical pieces of information. First, precise time data from atomic clocks onboard the satellite. Second, the satellite's exact orbital position. And third, the time when the signal was transmitted. These signals travel at the speed of light toward Earth.
The GPS receiver calculates its distance to each satellite by measuring how long the radio signal takes to travel from the satellite to the receiver. Since radio waves travel at the speed of light, the receiver can determine distance by multiplying the speed of light by the travel time. For example, if a signal takes 0.067 seconds to arrive, the distance is approximately 20,000 kilometers.
Once the GPS receiver knows its distance to at least four satellites, it uses a mathematical process called trilateration to determine its exact position. Each satellite distance creates a sphere around that satellite. Your location is where all these spheres intersect. Three satellites give you a 2D position, while four or more satellites provide 3D coordinates plus precise time synchronization.
GPS technology has revolutionized navigation and positioning worldwide. From helping you navigate to a restaurant, to enabling emergency services to locate you precisely, to supporting scientific research and autonomous vehicles, GPS is essential to modern life. The system typically provides accuracy within 3 to 5 meters, making it reliable for countless applications that depend on knowing exactly where you are on Earth.