Global Positioning System (GPS) and Satellite Requirement

How many GPS satellites are needed for the Global Positioning System to work?

For the Global Positioning System (GPS) to work, at any given time there must be at least ____________ (two/three) GPS satellites above the horizon.

Answer

Three satellites, because they use triangulation (three points) to find out your location.

The Global Positioning System (GPS) is a network of satellites that orbit the Earth and provide location information to GPS receivers on the ground. In order for the GPS system to accurately determine a user's location, it needs signals from multiple satellites.

While a minimum of four satellites are technically required for precise location determination, three satellites can still provide an approximate location. The GPS system uses triangulation, which involves measuring angles between the receiver and three satellites to calculate the user's position.

With three satellites in view, the GPS system can estimate the user's location by assuming they are at mean sea level. Each additional satellite improves the accuracy of the location data. Therefore, having at least three satellites above the horizon is essential for the Global Positioning System to function effectively.