How many satellites are required to determine latitude and longitude?

To determine latitude and longitude accurately using satellite technology, three satellites are typically required. Each satellite provides a distinct signal that allows a GPS receiver to triangulate its position.

The process begins with a GPS receiver picking up signals from these satellites. When the receiver calculates the distance to each satellite, it can use this information to find its location on the Earth's surface. The use of three satellites allows the receiver to obtain the latitude and longitude by creating overlapping spheres of distance measurement. The point where these spheres intersect is the precise location of the receiver.

Using just two satellites would not provide enough information for accurate positioning in three-dimensional space, since it would result in ambiguity about the receiver's altitude. An additional satellite, the third one, helps resolve that ambiguity and provides a more precise fix by allowing the receiver to compute its elevation as well, resulting in a more accurate geographical position.

However, in some advanced systems and situations, more than three satellites may be utilized to improve accuracy or reliability, but for basic calculations of latitude and longitude, three satellites are essential.