Patent ID: 6985212

Claim:
Method of laser scanning a perimeter zone of a target site for the detection of an object, said method comprising the steps of: pulsing a laser beam at a predetermined pulse repetition rate; oscillating said pulsed laser beam through a predetermined angle in a first direction; scanning said oscillating pulsed laser beam in a second direction across said perimeter zone; receiving echoes from said pulsed laser beam during said perimeter zone scan; deriving range data corresponding to said received echoes; determining two-dimensional position data of said received echoes in said perimeter zone; forming a three-dimensional scene image of a scan of said perimeter zone based on said range and two-dimensional position data of said received echoes thereof; repeating the steps of scanning, deriving, determining and forming for a plurality of perimeter zone scans to form three-dimensional scene images of each scan of said plurality; and comparing the three-dimensional scene images of said plurality to detect the object in said perimeter zone.