Trilateration

From Experimental Robotics

Introduction

Method of determining a POSITION using DISTANCES from THREE or MORE locations/landmarks/beacons/transmitters/etc.
Same process used in GPS.

More background information at Radio Localization (due to relevancy to both pages) or the lovely Wikipedia.com: http://en.wikipedia.org/wiki/Trilateration

If you were looking for HOW we used this, check Radio Localization

1 2 3

THREE readings are required to determine a 2D position, unless you wish to do something crazy like the Robosapien guys, or use the Earth as an imaginary sphere like in GPS.
You will need FOUR readings for 3D positioning.

ONE CELL

TWO CELLS

THREE CELLS