NCJ Number
57721
Date Published
1976
Length
7 pages
Annotation
A NEW PERIMETER INTRUSION DETECTION CONCEPT BASED ON AN ACTIVE ULTRASONIC TAPE INDUCER HAS BEEN FOUND FEASIBLE ON THE BASIS OF RESULTS SUMMARIZED IN THIS PAPER.
Abstract
A THEORETICAL ELECTROMECHANICAL MODEL OF THE PROPOSED MULTILAYERED ELECTRET TAPE TRANSDUCER WAS USED TO DETERMINE THE EFFECTS OF MANY PARAMETERS ON ITS PERFORMANCE AS A RECEIVER AND AS A RADIATOR OF ULTRASOUND. THIS INFORMATION WAS USED IN DESIGNING MODELS FOR FABRICATION AND TESTING IN THE LABORATORY. AFTER DEVELOPING A METHOD FOR POLING THE ELECTRET AND FOR CONSTRUCTING THE MULTILAYERS, RESEARCHERS FABRICATED SHORT SAMPLES AND TESTED FOR RECEIVING SENSITIVITY AND RADIATING EFFICIENCY. TWO LONGER, IMPROVED SAMPLES WERE THEN FABRICATED AND USED TO DEMONSTRATE THE FEASIBILITY OF THE INTRUSION DETECTION CONCEPT. THE ADVANTAGES OF THE ELECTRET TAPE SYSTEM ALLOW IT TO BE USED FOR A WIDE RANGE OF INDOOR AS WELL AS OUTDOOR PERIMETER PROTECTION APPLICATIONS. BECAUSE OF ITS EASY INSTALLATION, THIS SYSTEM HAS MANY APPLICATIONS FOR MOBILE VEHICLES THAT ARE UNATTENDED FOR EXTENDED PERIODS OF TIME, SUCH AS AIRCRAFT. OTHER USES INCLUDE THE PROTECTION OF VALUABLE OR DANGEROUS MATERIALS, SUCH AS OIL, FUEL, AND HIGH EXPLOSIVES. THE FEASIBILITY STUDY, AIMED AT INVESTIGATING THE TRANSDUCER PORTION OF THE NEW CONCEPT, YIELDED SEVERAL RESULTS: THE ULTRASONIC DOPPLER DETECTION CONCEPT APPEARS TO BE SOUND AND THE ELECTRET TAPE DEVELOPED APPEARS TO BE AN ADEQUATE SOURCE AND RECEIVER FOR SUCH A SYSTEM; SIGNIFICANT IMPROVEMENTS FOR MAKING SHORT TAPE TRANSDUCERS CAN BE MADE IN FUTURE SAMPLES; AND A COMPUTER-IMPLEMENTED MODEL OF THE TRANSDUCER HAS BEEN DEVELOPED FOR USE IN ASSESSING ITS PERFORMANCE AS A RADIATOR, RECEIVER, AND IN A DETECTION SYSTEM. ILLUSTRATIONS, GRAPHS, AND REFERENCES ARE PROVIDED. SEE ALSO NCJ 38864, 52569, 57707-57720, AND 57722-57726. (AUTHOR ABSTRACT MODIFIED--PRG)