Near Ultrasonic Pattern Comparison Intrusion Detector.
Patent, Filed 24 Jun 85, patented 27 Jan 87,
DEPARTMENT OF THE NAVY WASHINGTON DC
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An intrusion detector is configured to transmit signals of a very short duration and then process the returned signals reflected from various surfaces and objects within the propagation path in a room to be secured. The return signals is a succession of peaks whose return times represent the location of respective objects. As configured, the intrusion detector apparatus includes, inter alia, a microprocessor that stores processed facsimiles of the return signals for an unoccupied room and continually makes comparisons with subsequent returned signals. When the returned signals changes, as a result of an unauthorized entry into the room, for example, a visual andor audible alarm indication is produced.
- Miscellaneous Detection and Detectors