Abstract: A resilient antenna disturbance detector is provided. A signal generator generates an unclonable integrity test signal. The antenna reflects a signal in response to the integrity test signal. A comparator determines whether the reflected signal matches the integrity test signal and a controller signals the disturbance of the antenna to a monitoring device if the energy level of the reflected signal is greater than a predetermined threshold and the reflected signal matches the integrity test signal. The detector provides the advantage of preventing an external receiver and transmitter from predicting and transmitting the integrity test signal to the antenna to interfere with disturbance detection. Also provided is a security system with resilient antenna disturbance detection.

Abstract: An infra-red motion detector for monitoring motion in a monitored space is described. The motion detector includes, within a housing, an infra-red radiation sensor sensitive to infra-red radiation incident through a window. A refractive optical system within the housing selects incident infra-red radiation for redirection onto the infra-red sensor. An external light source mounted externally of the housing directs external light through the window providing a recognizable light input. A refractive Fresnel patch mounted externally to the window selects incident light from the external light source and redirects it to a tamper sensor within the housing. A detection controller processes signals output by both sensors in monitoring the space. The detection controller detects incident light from the external light source and trips a tamper alarm in failing detection, and further detects changes in infra-red radiation in the monitored space and trips an intrusion alarm upon detecting changes.

Abstract: A resilient antenna disturbance detector is provided. A signal generator generates an unclonable integrity test signal. The antenna reflects a signal in response to the integrity test signal. A comparator determines whether the reflected signal matches the integrity test signal and a controller signals the disturbance of the antenna to a monitoring device if the energy level of the reflected signal is greater than a predetermined threshold and the reflected signal matches the integrity test signal. The detector provides the advantage of preventing an external receiver and transmitter from predicting and transmitting the integrity test signal to the antenna to interfere with disturbance detection. Also provided is a security system with resilient antenna disturbance detection.

Abstract: An infra-red motion detector for monitoring motion in a monitored space is described. The motion detector includes, within a housing, an infra-red radiation sensor sensitive to infra-red radiation incident through a window. A refractive optical system within the housing selects incident infra-red radiation for redirection onto the infra-red sensor. An external light source mounted externally of the housing directs external light through the window providing a recognizable light input. A refractive Fresnel patch mounted externally to the window selects incident light from the external light source and redirects it to a tamper sensor within the housing. A detection controller processes signals output by both sensors in monitoring the space. The detection controller detects incident light from the external light source and trips a tamper alarm in failing detection, and further detects changes in infra-red radiation in the monitored space and trips an intrusion alarm upon detecting changes.

Abstract: A lens assembly for a passive infrared motion detector has one or more rows of far field Fresnel lenses arranged on a substantially cylindrical sheet and operative to collect light onto a sensor location. A plurality of rows of mid/near field Fresnel lenses are arranged on a basically spherical sheet, and the mid/near field lenses are operative to collect light onto the sensor location. An infrared motion detector also has an infrared sensor with a lens assembly having a plurality of lenses on a spherical surface collecting light from a corresponding number of zones onto said sensor, and a reflector mounted in the detector directs light collected by at least one of the lenses onto the sensor for providing one or more creep zones.