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 (which is
based on the
angles 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.)