Patent ID: 7414568
Filing Date: 2008-08-19
Classification: G01S

Abstract:
1. A laser warning receiver comprising an aperture in a detection channel with a fixed field-of-view (FOV) and a first optical filter before a detector whereby any laser beam originating from a source in that FOV will extend through the aperture and filter and onto the detector which will provide a signal in response to the detection of a laser beam, that signal being applied to one input of a pulse analyzer circuit, the receiver further comprising a localization channel with a second filter similar to the first filter and a lens selected to have a similar FOV as the one in the detection channel, both channels being arranged to be directed to the same FOV, the lens focussing the FOV onto a second detector through an N×M liquid crystal display (LCD) matrix, a laser beam originating from a source in that FOV will, provided the N×M elements in the matrix are transparent, produce an output from the second detector which is applied as an input to the pulse analyzer circuit to which the second detector is connected, an output from the pulse analyzer circuit being connected to a LCD pattern selector which is connected to the LCD matrix and provide control signals to the matrix that determines which elements are transparent and which ones will block light received from reaching the second detector, said selector providing a transparent window in said matrix, the size of the window and its position being variable with any laser beam detected by the second detector passing through the window, the location and size of the window being iterative varied and made smaller by the pattern selector, when a laser beam is detected, the position of the resulting smaller window on the matrix determining the co-ordinates of the originating source of a detected laser beam.