Alarm system for intrusion detection of an object moving in the proximity of an object to be protected

摘要

1. Alarm system for determining the intrusion of a moving object into the surroundings of an object to be protected, with a transmitter means for radiating pulsed electromagnetic wave signals and a receiver means for detecting electromagnetic energy reflected from the intruding object, with a range gate which is time-delayed with respect to the transmitted pulses and analysis of the moving target signals passed by the range gate, for the purpose of forming a radial limited alarm zone in the desired distance bracket surrounding the object to be protected in the manner of shells, whereby the depth of the alarm zone is small compared with the distance of the alarm zone, characterized by determining the radial path covered by the intruder within the alarm zone from the difference of the numerical values of added positive and negative Doppler periods of the reflected moving target signals (dE ).