Accession Number:

ADD014515

Title:

Optical Motion Detector Detecting Visible and Near Infrared Light.

Descriptive Note:

Patent, Filed 31 May 89, patented 20 Feb 90,

Corporate Author:

DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s):

Report Date:

1990-02-20

Pagination or Media Count:

10.0

Abstract:

An optical motion detector detects changes in scene lighting indicative of motion and is also capable of detecting surveillance by active night vision devices using near-infrared light. The detector includes two photodetectors which each provide data to a signal processing network. One photodetector is sensitive to visible light the other to near-infrared light. Both signal processing networks are identical and include a sample-and-hold, a comparator network, and a pulse stretcher. The output of a photodetector is provided to the sample-and-hold and comparator network. The comparator network compares a voltage corresponding to the instantaneously detected ambient lighting scene with a voltage corresponding to a reference lighting scene. The pulse stretcher receives the output of the comparator network and in turn provides an output to a logical processor. The logical processor compares the outputs of both signal processing networks and provides an output indicating surveillance with near-infrared light. The logical processor also indicates any perturbations in intensities of incandescent and fluorescent light. Patents. edc

Subject Categories:

  • Optical Detection and Detectors
  • Infrared Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE