Trilateration is the method of determining the position
of a point,
given the distance
to three control points
, as opposed to
the more commonly known method, triangulation
based on the angle
s between said control points).
Trilateration can be applied to many different areas, e.g.
geograpic mapping, navigation (e.g. GPS systems), and due to the progress in electronic distance-measuring it is preferred to triangulation.
(Trilateration has been successfully applied to a positioning system
where a number of beacons emit signals, from which a device
can determine its position. In this case, however, the device
only knows the differences in distance, and a fourth
beacon had to be used.)