What is indicated by utilizing four satellites in GPS technology?

Using four satellites in GPS technology is essential for accurately determining a three-dimensional position, which includes latitude, longitude, and elevation. The key reason this is significant lies in the requirement for a fourth satellite to resolve the ambiguity in the timing aspects of satellite signals.

When a GPS receiver calculates its position, it does so based on the time it takes for signals to travel from the satellites to the receiver. If only three satellites were used, the data gathered could pinpoint a location on a two-dimensional plane but would leave uncertainty regarding elevation. The addition of a fourth satellite allows the GPS receiver to triangulate its position with enough precision to derive the altitude as well, thereby ensuring a fully accurate three-dimensional location.

This is crucial for numerous applications such as navigation, surveying, and geological analysis, where knowing the elevation is just as important as knowing geographic coordinates. By using four satellites, the system compensates for the discrepancies in time signal reception and provides not just horizontal positioning but also a correct vertical position.