trilaterate

Trilaterate is a verb that describes the process of determining a location based on its distance from three known points. This method is widely used in various fields, including navigation, surveying, and satellite positioning systems. The principle behind trilateration is geometric. Imagine circles drawn around each of the three known points, with the radius of each circle representing the measured distance to the unknown point. The intersection of these three circles, or spheres in three-dimensional space, pinpoints the exact location of the unknown point.

In practical applications, such as GPS, satellites act as the known points. A GPS receiver on Earth measures the time it takes for signals to arrive from multiple satellites. Knowing the speed of light, this time can be converted into a distance from each satellite. By receiving signals from at least four satellites (three for position, and one for time correction), the receiver can calculate its precise position in three dimensions. Trilateration relies on accurate distance measurements; any error in these measurements will lead to inaccuracies in the calculated location. Surveying often uses trilateration with terrestrial measurements, where distances are measured between known control points and the point to be located.