INTRUDER DETECTING SECURITY SYSTEM

摘要

INTRUDER DETECTING SECURITY SYSTEM This electronic perimeter intruder detecting security system is arranged for measuring the differences of propagation times and/or velocities of a plurality of different seismic-like waves simultaneously set up by an intruder at a plurality of sensor stations and for calculating the location, velocity, and frequently for identifying the type of intruder. Provisions are disclosed for screening false alarms or waves emanating from without a guarded zone and for ignoring waves from sources not of interest in guarding that zone.