Abstract: Method and device for thermal imaging and rangefinding. In one form the device comprises an optical system including a first aperture and first, second and third optical paths each passing through the first aperture. A polarizer positioned to segregate the first and second optical paths is capable of receiving polarized radiation reflected from the target and transmitted through all portions of the first aperture stop. A polarization modifier is positioned between the first aperture and said polarizer; and a beam splitter, sensitive to spectral differences between the polarized radiation and the thermal radiation, is positioned along the first optical path between the first aperture and said polarizer.

Abstract: A forward looking infrared (FLIR) energy imaging device has been found to include components which are required by the receiver portion of a long-wavelength rangefinder. For example, the FLIR collecting lens system which focuses energy from a scene onto a sensitive, cooled detector array duplicates the function which must be performed by the laser rangefinder receiver. Thus an integrated laser/FLIR rangefinder comprises a laser transmitter for illuminating a target, and an IR energy optic channel having a FLIR for receiving IR energy and producing a visible image representative thereof, said FLIR including an afocal lens system for collecting and focusing energy from the target and energy from the laser return having a wavelength compatible with the band pass of the IR optics and detector onto a cooled sensitive detector.

Abstract: In an integrated laser/FLIR rangefinder a scanner position sensor comprising an LED of the array of LEDs of a forward looking infrared (FLIR) system, a reticle grating located at the image plane of LED optical path, and a silicon detector positioned to receive the light passing through the reticle grating for producing a plurality of signals in response to light passing through each grating slot. One of the signals is selected for the synchronization logic for controlling the charging and firing of the laser. If there is no range return a second signal is selected for adjusting the position of the timing pulse.