Intrusion detection system

专利名称：Intrusion detection system发明人：Robert K. Harman,Andre Gagnon申请号：US08/214007申请日：19940316公开号：US05510766A公开日：19960423

摘要：In an intrusion detection system comprising an open transmission line (10), forexample a \"leaky cable\frequency signal received by the line to detect perturbations caused by an intruder (28),problems of nonlinear sensitivity due to line attenuation are resolved by combiningperturbation signals (R.sub.S, R.sub.T) from both ends of the open transmission line. Aprocessor unit (18) computes logarithmic values of the perturbation signals from theopposite ends of the line and combines them to detect presence of an intruder. The sumof the logarithmic values may be used to determine presence of the intruder and thedifference between them may be used to determine the location of the intruder relativeto the end of the line. The processor may also use phase information from the twoperturbation signals to facilitate detection in the presence of multipath effects.

Reference signals (LO,IF.sub.T, RF) and power may be transmitted between receiver units(12S,14S, 12T,14T,16) by way of the open transmission line (10) itself. The system mayemploy several transmissions having different frequencies, in which case the processor(18) will sum perturbation signals for all transmission frequencies for each end of the line,combine the two sums, and compare the result with a predetermined threshold T.

申请人：AURATEK SECURITY INC.

代理人：Thomas Adams

更多信息请下载全文后查看