| 摘要 |
A transducer cable (5) includes outer conductor (1) inner conductor (2). die lectric (6) therebetween, and a longitudinal passage (4) with sense wire (3) loosely disposed therein extending through said dielectr ic. Intruder-caused vibration (7) of the cable results i n relative movement of the sense wire and outer conductor. causing corresponding sense wire impedance change. A carrier signal (8) transmitted down the inner conductor electromagnetically couples energy to the sense wir e. Said impedance change causes reflection of some of th e coupled energy, the reflection is sensed by a receiver circuit that in turn produces an indication of intrusion. The receiver circu it includes a system that digitizes the received signals at successive times that corres pond to successive sections of the cable, and produces t arge response values for sections of the cable undergoing impedance changes. Tar get responses in several adjoining sections are interpol ated precisely locate the intruder-caused vibration.
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