Research Information System
9th WSEAS International Conference on Applied Informatics and Communications, Moscow, Russia, 20 - 22 August 2009, pp.225-226
A rangefinder is a device that measures distance from the observer to a target, for the purposes of surveying, determining focus in photography, or accurately alining a weapon. Some devices use active methods to measure (such as sonar, laser, or radar); others, available since the nineteenth century, measure distance using trigonometry (stadia metric rangefinders and parallax, or coincidence rangefinders). They usually use a set of known distances or target sizes to make the measurement [2].