초록 ▼

A pulsed conductivity sensor intrusion detection device which uses the conduction of short electrical pulses on or near the surface and the immediately adjoining air above the surface. An intruder causes the propagated signal to change which is sensed by the Pulsed Conductivity Sensor (PCS) and prod

A pulsed conductivity sensor intrusion detection device which uses the conduction of short electrical pulses on or near the surface and the immediately adjoining air above the surface. An intruder causes the propagated signal to change which is sensed by the Pulsed Conductivity Sensor (PCS) and produces an alarm. A path is protected by placing a transmitter and a receiver on either side with the protected region between them. An area is protected by placing transmitter and receivers around the periphery of the area. Pulses are sent from the transmitter to the receiver through the surface and the air immediately above it. The receiver sends the signal to an analyzer where the frequency/amplitude spectrum is determined using Fourier Transform techniques. Pulses are sent ten or more times per second and each is analyzed. By comparing sequential pulses, any change will be detected. Signatures for different subjects have been determined and are used to detect when a human intrusion occurs.

대표청구항 ▼

An intrusion detection system for use in an area to be protected comprising: a transmitter for transmitting pulses of RF energy, said pulses disposed for conduction on or near the surface of said area to be protected; a receiver disposed in spaced relation with said source of electrical pulses to re

An intrusion detection system for use in an area to be protected comprising: a transmitter for transmitting pulses of RF energy, said pulses disposed for conduction on or near the surface of said area to be protected; a receiver disposed in spaced relation with said source of electrical pulses to receive said electrical pulses therefrom; and processing means disposed for receiving sequential electrical signals corresponding to said electrical pulses and for determining the frequency/amplitude spectrum of said electrical signals and comparing said sequential signals to detect any changes in said signals, said processing means including Fourier Transform means for determining said frequency/amplitude spectrum of said electrical signals; and, said transmitter disposed for producing electrical pulses with an amplitude of 1 kv and above, an adjustable pulse width of between 5 to 50 ns, a risetime of less than 1 ns and a repetition rate of 10 or more pulses per second.