How many satellites must a GPS receiver receive signals from to locate its position in 2 dimensions?

How many satellites must a GPS receiver receive signals from to locate its position in 2 dimensions?

• A. 2
• B. 3
• C. 4
• D. 5

Answer: (B)

A GPS receiver requires signals from three satellites to determine its position in two dimensions, which includes latitude and longitude. When a GPS receiver receives a signal from a satellite, it calculates the time it takes for the signal to travel, which allows it to determine the distance to that satellite. However, to ascertain its precise position in two dimensions, the receiver needs triangulation from at least three satellites. The first satellite provides a spherical location (the distance from the satellite), but without additional signals, the receiver could be anywhere along that sphere. A second satellite narrows down the location to the intersection of two spheres, which reduces the possible positions to a circle. The third satellite allows the receiver to determine its exact position at a specific point within that circle by further defining the intersecting regions. This triangulation method is fundamental to how GPS technology works, as it effectively calculates the receiver’s position based on the distances from multiple satellites in orbit, refining the location down to precise coordinates. Having more than three satellites improves accuracy and helps determine altitude, which would require signals from four satellites to solve for three-dimensional positioning (latitude, longitude, and altitude). Thus, for two-dimensional positioning, three satellites are sufficient.

A GPS receiver requires signals from three satellites to determine its position in two dimensions, which includes latitude and longitude. When a GPS receiver receives a signal from a satellite, it calculates the time it takes for the signal to travel, which allows it to determine the distance to that satellite. However, to ascertain its precise position in two dimensions, the receiver needs triangulation from at least three satellites.

The first satellite provides a spherical location (the distance from the satellite), but without additional signals, the receiver could be anywhere along that sphere. A second satellite narrows down the location to the intersection of two spheres, which reduces the possible positions to a circle. The third satellite allows the receiver to determine its exact position at a specific point within that circle by further defining the intersecting regions.

This triangulation method is fundamental to how GPS technology works, as it effectively calculates the receiver’s position based on the distances from multiple satellites in orbit, refining the location down to precise coordinates.

Having more than three satellites improves accuracy and helps determine altitude, which would require signals from four satellites to solve for three-dimensional positioning (latitude, longitude, and altitude). Thus, for two-dimensional positioning, three satellites are sufficient.