Knowing exactly where you are on Earth once required careful surveying. The Global Positioning System, or GPS, uses a constellation of satellites to provide precise location and time information to receivers anywhere on or near the planet.

Each satellite broadcasts its position and the exact time. A receiver calculates its distance from several satellites by measuring signal travel time and then solves for its own three-dimensional position. Civilian accuracy is typically a few meters; specialized techniques achieve centimeter precision.

GPS has transformed navigation, surveying, agriculture, and logistics. Smartphones, aircraft, ships, and autonomous vehicles all rely on it. Complementary systems operated by other countries provide similar services. The technology depends on extremely accurate atomic clocks and continuous satellite maintenance.

• Satellite-based positioning and timing system
• Provides worldwide location information
• Uses signal travel time from multiple satellites
• Supports navigation, surveying, and countless applications