How does GPS determine your precise location on Earth?

GPS uses signals from satellites to find your location on Earth, just like how a map helps you find where you are.

Imagine you have four friends who each know exactly where they are in the sky. They shout down to you at the same time, telling you how far away they are. You can use that information to figure out where you are on the ground, like solving a puzzle!

Each satellite sends out a signal that travels through space and reaches your phone or GPS device. Your phone measures how long it took for the signal to arrive.

If one satellite tells you how far away it is, you can draw a circle around Earth showing all the places that could be where you are. But with more satellites, like four, each giving their own distance, your phone can find the one spot where all those circles overlap. That’s your location!

It’s just like when you use two different maps to figure out where you are, one from a friend who knows how far away they are from you, and another from someone else who also knows their distance. With more clues, it's easier to find the right place!