Abstract: An alarm filter (22) for use in a security system (14) to reduce the occurrence of nuisance alarms receives sensor signals (S1-Sn, Sv) from a plurality of sensors (18, 20) included in the security system (14). The alarm filter (22) produces an opinion output as a function of the sensor signals and selectively modifies the sensor signals as a function of the opinion output to produce verified sensor signals (S1?-Sn?).

Abstract: A system for testing radio frequency (RF) communications of a device capable of such communications is provided. The system includes a chamber for isolating the device from RF interference, an antenna that is suitable for RF communications with the device wherein the antenna is capable of communications over a range of frequencies, the antenna being located within the chamber, and a digital communication link for providing non-RF communications with the device.

Abstract: An intrusion detection and tracking system includes a plurality of nodes, a DP and a gateway. The nodes are disposed about an area and form a wireless network to be monitored, the nodes are configured to receive data and transmit data frames with a signal strength indicator and/or a link quality indicator in the frames. The DP is communicatively connected to the network and configured to analyze variations in the signal strength indicator and/or link quality indicator to detect and track disturbances to an electromagnetic field in the area. The gateway is configured to form a data link between the network and the DP.

Abstract: An intrusion detection and tracking system includes a plurality of nodes, a DP and a gateway. The nodes are disposed about an area and form a wireless network to be monitored, the nodes are configured to receive data and transmit data frames with a signal strength indicator and/or a link quality indicator in the frames. The DP is communicatively connected to the network and configured to analyze variations in the signal strength indicator and/or link quality indicator to detect and track disturbances to an electromagnetic field in the area. The gateway is configured to form a data link between the network and the DP.

Abstract: There is disclosed apparatus and methods for a directed energy beam virtual fence. The directed energy beam virtual fence may include a source unit to provide an energy beam and a sequence of relay units disposed at intervals along the length of the virtual fence. Each relay unit in the sequence may receive the energy beam from a previous unit and may recollimate and redirect the energy beam towards a subsequent unit.

Abstract: An Apparatus for remote inspection of emergency equipment at one or a system of emergency equipment stations includes, e.g., at each emergency equipment station: a detector for detection of the presence of an obstruction to viewing of or access to the emergency equipment station; and an electronic circuit in communication between the detector and a remote central station for issue of a signal to the remote central station upon detection of the obstruction to viewing of or access to the emergency equipment station.

Abstract: A security system for a boundary is generally shown as (1) in FIG. 1. The components comprise an elongate member (2) and a support (3) for the bar. The bar support (3) can be fitted to boundary support. A conduit (7) extends through the housing (3). The rod is surrounded by a resilient member. The boundary supports (4) and the bars (2) are in communication with a circuit monitor unit (17) and from an electromechanical disturbance mechanism (EMDM) unit for detecting security breakdown of the boundary.

Abstract: A motion detector for detecting a tampering within a detection zone. A vibration-sensing unit sensitive to vibrations applied to the detector is provided to produce a vibration output signal representative of a detected parameter of the vibrations. A light-sensing unit sensitive to light in a predetermined spectrum is provided to produce a light output signal representative of a detected parameter of the light in the predetermined spectrum. A processing unit is further provided to determine if the vibration output signal is consistent with a predetermined model indicative of a tampering and producing an activating signal accordingly.

Abstract: An advanced technology screening checkpoint system includes a baggage screening zone, a passenger screening zone, and a secondary screening zone. The baggage screening zone may include an explosives scanning system and an imaging system, while the passenger screening zone may include an explosives detection portal and a self-divestment portal to show passengers what to divest prior to screening by a high sensitivity metal detection portal. In some implementations, a secondary screening zone includes a sealed-bottle scanning system, an enhanced explosives detection system, a weapons search routine, and a body scanning system. Centralized monitoring of screening results for individual detection and screening systems of the baggage, passenger, and secondary screening zones may be provided by a combined user interface (CUI).

Abstract: An ergonomically designed metal detector is provided. The metal detector allows for operation of the metal detector between two modes of operation while maintaining an operator's hand position relative to the surface.

Abstract: An intruder detection system includes a leaky transmission path of a transmission side and a leaky transmission path of a receiving side, both of which has a plurality of leaky points existing in a direction to which the respective leaky transmission path extends, and the intruder detection system further includes an intrusion location detection unit which detects an intrusion location of an intruder on the basis of each signal, which is received in a receiving circuit of the receiving side, affected by the leaky electric wave at each of the leaky points. The intruder detection system further includes a detection table which associates a detectable intrusion location with a detection area, and if intrusion location detection information of the intrusion location detection unit corresponds to a detection area of the detection table, a detection result is output.

Abstract: A method determining a malfunction when a reception signal fluctuates at a receiver owing to malfunctions occurring on a leaky cable and its related devices. The method determines, among range bins correlating the reception signal with a distance from a feed end of a radio-wave radiation unit and a radio-wave reception unit, based on a correlation between a time-delay from a transmission time of a transmission signal until a reception time of the reception signal and a transmission path distance of the reception signal in the radio-wave radiation unit and the radio-wave reception unit, when, comparing the reception signal with the transmission signal with respect to the range bin corresponding to a far end, a level of amplitude reduction in the reception signal exceeds a predetermined ratio, that a malfunction is present in either the radio-wave radiation unit or radio-wave reception unit.

Abstract: A detector, system including a detector and method for sensing motion within a detection region. The detector has a detection element and a focusing element aiming received energy corresponding to a presence within the detection region toward the detection element. The focusing element has a plurality of sections in which each of the plurality of sections establishes a corresponding detection zone within the detection region. The plurality of sections are arranged to allow a motion vector to be determined for an object passing through the detection region. The system includes a detector that generates pulses each time presence in a detector zone is detected as well as a central alarm panel. The central alarm panel receives the pulses and has processor that evaluates the timing between electrical pulses to determine the motion vector.

Abstract: An interrogating system can include an interrogating apparatus configured to transmit toward and receive from a subject in a subject position, millimeter-wave electromagnetic radiation. Such a system can also include a controller configured to operate the interrogating apparatus, and produce data representative of a characteristic of the subject from received radiation. Some embodiments of such an interrogating system may include interrogating apparatus adapted to be mounted to a vehicle or at a vehicle loading zone, to interrogate passengers and/or other persons prior to boarding or accessing the vehicle. Such embodiments may include one or more controllers positioned within the vehicle or at the loading zone.

Abstract: A method and system for controlling lighting in a space reduces energy consumption of the light sources by changing at least one of the color rendering index (CRI) and the correlated color temperature (CCT) while maintaining illumination levels. Preferably, the method and system sense movement of people in the space relative to light sources that light the space, and automatically and individually adjust plural solid state lighting devices that form each of the respective light sources to a first lighting condition when people are in a first position, wherein the lamps respectively emit light of a first illumination level and a first CRI at a first electrical power level, and to a second lighting condition when people are in a second position, wherein the light sources respectively emit light of the first illumination level and a smaller CRI than the first CRI and at a lower electrical power level than the first electrical power level.

Abstract: A security system comprises a system control panel for monitoring at least one device on a network. An infrared (IF) sensor located on the network has an IR transmitter and an IR receiver. The IR transmitter transmits control data packets and the IR receiver detects received data packets and IR data. A processor provides the control data packets to be transmitted by the IR transmitter. The processor determines that an external communication device is initiating communication with a target device over the network based on at least the received data packet received by the IR receiver. The processor establishes bi-directional communication over the network between the external communication device and the target device which is one of the processor, the system control panel and the at least one device.

Abstract: A fabrication process produces markers for a magnetomechanical electronic article surveillance system. The marker includes a magnetomechanical element comprising one or more resonator strips of magnetostrictive amorphous metal alloy; a housing having a cavity sized and shaped to accommodate the resonator strips for free mechanical vibration therewithin; and a non-deactivatable bias magnet adapted to magnetically bias the magnetomechanical element. The process employs adaptive control of the cut length of the resonator strips, correction of the length being based on deviation of the actual marker resonant frequency from a preselected, target marker frequency. Use of adaptive, feedback control advantageously results in a much tighter distribution of actual resonant frequencies. Also provided is a web-fed press for continuously producing such markers with adaptive control of the resonator strip length.

Abstract: A remote wellness monitoring system with universally accessible interface consists of an apparatus or home appliance unit running an embedded software program connected to a server computer via a phone line or high-speed internet. At home, the apparatus communicates with an optional set of medical health monitoring devices using wired or wireless communications methods in order to perform wellness measurements. Embodiments of the invention provide a novel user interface on the home appliance to make the system accessible to people with disabilities. The simple user interface is designed to be accessible to people who are blind or deaf or people who cannot use their hands and require an alternative interface device such as a sip & puff controller. The home unit can further monitor wellness activity of the care recipient by pegging the number of times the care recipient passes by an infra-red motion sensor.

Abstract: Under the present invention, a wireless sensor network comprising a plurality of peer to peer nodes is provided. Each node in the network includes, among other things, a sensor for detecting environmental factors. When a potential failure is detected within a node, the node will query its neighboring nodes to determine whether they have the capability to store any data component(s) currently stored within the potentially failing node. Based on the querying, the data component(s) in the potentially failing node are copied to one or more of the neighboring nodes. Thereafter, details of the copying can be broadcast to other nodes in the network, and any routing tables that identify the locations of data components stored throughout the wireless sensor network can be updated.

Abstract: An object information acquisition apparatus for acquiring information on the inside of an object includes an electromagnetic wave generation unit capable of outputting a terahertz wave and of changing the output intensity, an irradiation unit that irradiates an electromagnetic wave onto an object, a scanning unit and a detection unit that detects the electromagnetic wave irradiated onto the object. The scanning unit changes the relative positions of the irradiated electromagnetic wave and the object. The detection unit detects the electromagnetic wave transmitted through or reflected by the object as a result of interaction of the object and the electromagnetic wave.

Abstract: An apparatus for monitoring an access portal through an enclosure around a hazard comprises a line-scan camera mounted above the portal so that its linear field of view extends along a generally opposite threshold of the portal and can detect electromagnetic radiation reflected from an object passing through the portal. The apparatus distinguishes signals from the camera corresponding to items that are intended to pass through the portal for example on a conveyor from signals corresponding to items, particularly intruders that are not intended to pass through the portal. The apparatus preferably comprise an elongate sodium discharge lamp mounted above the portal and provided with a reflector so that monochromatic light therefrom is concentrated in a narrow strip extending along the threshold and the camera is sensitive only to this monochromatic light.

Abstract: According to an embodiment, an intrusion detection sensor includes a microwave sensor (120) that transmits microwaves toward a detection area, receives the microwaves reflected by an object present in the detection area, and outputs a reflected wave reception intensity signal according to the received intensity; a direction variable antenna device (110); a scanning measurement means (131) that provides an instruction to scan the transmission/reception direction to the direction variable antenna device (110) to determine a relationship with the output of the reflected wave reception intensity signal; a detection target object presence determination means (132) that determines whether or not a detection target object is present based on the determined relationship; and an alarm signal output control means (133) that outputs an alarm signal when it is determined that a detection target object is present.

Abstract: A self-contained motion sensitive audio module includes a sensor circuit coupled to a pyroelectric infrared sensor with two sensing elements configured for reliably sensing passersby. The module also includes a power supply, a timing circuit, an audio circuit, a speaker and optionally an LED. The sensor circuit produces an amplified trigger signal when a passerby is sensed. The sensor circuit includes an amplifier to amplify the trigger signal. The timing circuit produces an activation signal upon receiving a trigger signal from the sensor circuit. In playback mode, the audio circuit produces an audible sign message output upon receiving an activation signal from the timing circuit. The module may be attached to the back side of a sign with apertures for receiving the sensor, speaker and optionally an LED.

Abstract: An intrusion detector comprising a passive sensor for detecting a person entering a space to be monitored, said intrusion detector comprising a housing provided with a window for said passive sensor, optical means for directing electromagnetic radiation from said person onto the passive sensor, alarm means connected to said passive sensor for generating an alarm in case the electromagnetic radiation from said person being detected by the passive sensor corresponds to a signal value that exceeds a maximum level or falls below a minimum level, a special feature being the fact that the optical means are provided with a mirror curved in two directions for forming at least one protective curtain extending in a vertical plane in the space to be monitored, wherein the passive sensor is disposed on the optical axis at the focus of the mirror, and wherein the mirror directs a beam of electromagnetic radiation from the person, rotated through at least 45°, preferably through at least substantially 90°, onto the passive

Abstract: A system capable of monitoring an area and detecting a disturbance with the area. The system has a plurality of ultra-wide band radio frequency tags, each of the tags including a digital signal processing module configured to monitor changes in radio frequency multipath properties of received packets transmitted by at least one other of the tags. Changes in the radio frequency multipath properties may be caused by a disturbance indicative of an object in the vicinity of the tags. A corresponding method is also disclosed.

Abstract: An in-container monitoring sensor system is based on an UWB radar intrusion detector positioned in a container and having a range gate set to the farthest wall of the container from the detector. Multipath reflections within the container make every point on or in the container appear to be at the range gate, allowing intrusion detection anywhere in the container. The system also includes other sensors to provide false alarm discrimination, and may include other sensors to monitor other parameters, e.g. radiation. The sensor system also includes a control subsystem for controlling system operation. Communications and information extraction capability may also be included. A method of detecting intrusion into a container uses UWB radar, and may also include false alarm discrimination. A secure container has an UWB based monitoring system.

Abstract: An apparatus for remote inspection of fire extinguishers at one or a system of fire extinguisher stations includes, e.g., at each fire extinguisher station: a detector for lack of presence of a fire extinguisher in its installed position at the fire extinguisher station; a detector for out-of-range pressure of contents of the fire extinguisher at the fire extinguisher station; a detector for an obstruction to viewing of or access to the fire extinguisher at the fire extinguisher station; and a device for communication of inspection report information by wireless signal between the fire extinguisher station and a remote central station.

Abstract: A warning system for notifying another person when a child is left in a child safety seat. The system recognizes a child in a child safety seat by either a pressure pad or a secured child seat lap belt. The system is activated by the release of the driver's seat belt. Should a child remain in the seat when the driver's seat belt is disengaged, the system alarms notifying the driver of such. The alarm would include a calm audio output such as a lullaby, a song, or a story. The system can be integrated into the OEM features to provide an alert escalation process using a local alert, a vehicle alert, a wireless alert and ultimately a 911 alert.

Abstract: A system, device, and method for monitoring an uncontrolled area around a mobile object uses a distributed antenna, which can be a leaky coaxial cable, enclosing its perimeter. A field disturbance sensor, such as a microwave sensor, detects an intruder entering a protected area defined by field of the antenna. An alarm signal is sent to a wireless transceiver for transmission of an alarm event to a remote station. A biometric sensor, such as a passive infrared heat detector, can be used in conjunction with the field disturbance sensor to reduce possible false alarms. Identification of a legitimate alarm may alternatively be verified with video images obtained near an area of interest in proximity to the mobile object, which may be forwarded by the wireless transceiver to a remote station for analysis.

Abstract: A device for the detection of the passage of objects, people or animals bearing a radio frequency identification (RFID) tag, including at least one mobile support which, when at rest, forms a barrier to the passage of the objects, people or animals and which, when in contact with the latter, is capable of moving towards a withdrawn position, this mobile support bearing an antenna connected electrically to an RFID tag reader.

Abstract: Embodiments of the present invention are directed to a method and system for use of ranging MW to decrease MW intrusion detector false alarms. A Doppler microwave system may be provided that is capable of detecting an object range and adjusting the sensitivity of an alarm stage of a MW detector to account for object size and range. Multiple range limited MW stages may be configured for different ranges to determine the general range of the moving object. Based on signal levels present on these MW stages, an approximate object range may be determined. The sensitivity of the MW alarm stage is then adjusted based on a MW alarm state sensitivity vs. object range function that is optimized to alarm on humans and ignore small animals and insects. The method and system may be used in detection systems incorporating a MW sensor.

Abstract: A hybrid-technology metal detector, using pulse-induction and sine-wave excitation of the transmitter coil alternately, in rapid succession. The energy stored in the transmitter coil, in the pulsed mode, is used to shock-excite a high-Q circuit formed by the coil and a parallel capacitor into oscillations in the sine-wave mode. The multiplicative action of the circuit Q causes high currents to flow in the transmitter coil, causing high fluxes to be impressed on the searched area, with increased sensitivity as a result. Using a linear coil-current ramp to assess and minimize the coupling between the transmitter and receiver coils permits effective separation of the reactive and resistive components of the target signals, making accurate identification of targets possible.

Abstract: In a communication network or networked system, cables that interconnect systems or parts of a system are provided with RFID tags embedded at periodic intervals along their lengths. A network of GPS-enabled RFID readers with triangulation capabilities enables the determination of the physical routing of cables within an area of interest. It also enables communication of the physical routing information to an operations support system for cable management.

Abstract: A telecommunications optical fiber is secured against intrusion by detecting manipulation of the optical fiber prior to an intrusion event. This can be used in a non-locating system where the detection end is opposite the transmit end or in a locating system which uses Fresnel reflections and Rayleigh backscattering to the transmit end to detect and then locate the motion. The Rayleigh backscattering time sliced data can be stored in a register until an intrusion event is detected. The detection is carried out by a polarization detection system which includes an optical splitter which is manufactured in simplified form for economic construction. This uses a non-calibrated splitter and less than all four of the Stokes parameters. It can use a polarimeter type function limited to linear and circular polarization or two linear polarizers at 90 degrees.

Abstract: A sensing device for detecting an approaching object is composed of a sensor section that includes a detection electrode supplied with a detection source signal having a prescribed frequency and another detection electrode disposed in close vicinity to the detection electrode, a communication signal amplifier that amplifies the communication signal and outputs the amplified communication signal as an amplifier output signal, an integrator that integrates the amplifier output signal and outputs a judging signal for judging whether or not an object approaches the sensor section, and a detection sub-signal switch that is disposed between an output side of the communication signal amplifier and an input side of the integrator. A communication signal is obtained from the detection source signal that is transmitted to the other detection electrode from the detection electrode and attenuated thereat when an object approaches the sensor section.

Abstract: The intruder detection device for deciding the occurrence of an invasion if an electric wave, which is received by a leakage transfer passage on the receiving side juxtaposed to a leakage transfer passage on the transmitting side for receiving a leakage electric wave from the transmitting leakage transfer passage, changes, and the intruder detection device comprises: a plurality of reference spectrum diffusion signal generating means; a plurality of correlating means configured together with the reference spectrum diffusion signal generating means on a common sensor card, for collating the output reference spectrum diffusion signal of the reference spectrum diffusion signal generating means with the received signal from the receiving leakage transfer passage; and setting means for adjusting the detection precision which is determined by the reference spectrum diffusion signal generating means and the correlating means.

Abstract: A method and means for controlling the operation of a machine by an operator having a transmitter mounted to a machine, a sensor attached to an operator or an operator's clothing, and a tracking device that receives signals from the sensor and determines the position of the sensor. Based on the determined position of the sensor, the tracking device sends signals to the operator and an actuator on the machine based on a comparison with a danger zone, warning zone, or operator zone.

Abstract: An intrusion detection system that is capable of foliage penetration is disclosed employing an array of field disturbance transceivers operating at UHF frequencies. The array of transceivers generate a multiplicity of RF fields between nearby units and detect the presence of intruders by detecting disturbances in these fields. The emitted UHF signals used to generate the RF fields are also used to provide a communication link between transceivers in the array and to a control station. The control station facilitates the operation of the array from a remote monitoring site. A method of array deployment provides multiple opportunities to detect an intruder and secondarily provides redundant communication links in case of a sensor failure. Automatic means of setting detection thresholds based on environmental conditions assures a high probability of detection along with a low false alarm rate.

Abstract: A system to control energy consumption in a room uses a wireless mesh network that allows for continuous connections and reconfiguration around blocked paths by hopping from node to node until a connection can be established, the mesh network including one or more wireless area network transceivers adapted to communicate data with the wireless mesh network, the transceiver detecting motion by analyzing reflected wireless signal strength.

Abstract: Embodiments of a passive infrared detector can distinguish between an intruder and a small animal passing nearby the detector with a high degree of accuracy without substantially detracting from the ability to detect the intruder within a coverage area farther from the detector. In some embodiments, the passive infrared detector includes a pair of lens assemblies that collect infrared light onto corresponding infrared sensors. Each lens assembly receives light from different spatial regions, which do not overlap near the detector and which substantially overlap farther from the detector. The passive infrared detector also includes a controller that is capable of distinguishing between an intruder and a small animal based on simultaneity of signals from the infrared sensors or by summing the signals from the infrared sensors.

Abstract: The present invention is directed to an underground as well as above ground system and method of determining the intrusion into a security zone. One or more transceivers would transmit a unique electromagnetic signal which would power a response from one or more RFID transponders. Each of the transponders would transmit a unique code to the transceiver indicating that there has been no intrusion in the vicinity of that transponder. Failure of a transponder to receive a signal produced by a transponder, would indicate the existence of an intrusion. The transponders as well as the transceivers can be provided in a PVC pipe buried in the ground, or provided in or on a structure located on or above the ground.

Abstract: A secure sealed container and mounting pole house any of a variety of security equipment. Sensing equipment, a high decibel siren, and strobes simulating police lights are removably attachable to a universal mount and control circuit. A control panel connected to the circuit enables and disables the alarm, and monitors system activity.

Abstract: Intrusion detection methods and apparatus exploit the infrastructure of the building itself. The preferred embodiments use the existing power line infrastructure to provide power, data, and sensor observables to a monitoring system which is simply connected at one point, namely, the connection of the building to the city power grid. Computer network interfaces may also be used. In terms of sensors, impedance, capacitive, inductive, electric field and Radar modalities may be used.

Abstract: Improved alarm system that is able to distinguish intrusions by persons from intrusions by others, such as nonhuman animals and inanimate objects. Multiple sensors are placed in a vertically aligned array, so that each sensor monitors at a different elevation. As animals and other objects generally have different sizes and shapes than humans, the vertically spaced sensors will detect different intrusion patterns than the intrusion patterns typically generated by a human. By analyzing these different intrusion profiles and only signaling an alarm when a profile resembling an intrusion by a person occurs, a number of false alarms can be avoided.

Abstract: At least one antenna array including three mutually orthogonal antennas each sharing a common center point senses an electromagnetic signal emitted by a buried object such as a utility line, pipe or sonde. A circuit at least partially mounted in a housing is connected to the array and determines a location of the buried object by measuring signal strength and field angles in three dimensions without having to align the antenna array relative to the buried object while eliminating nulls and false peaks. A graphical user interface (GUI) has user-friendly icons, symbols, menus, numbers and graphical and auditory representation of signal strength. A plurality of different underground objects can be simultaneously detected and their different locations can be simultaneously indicated to a user via audible sounds and/or visual images on a display.

Abstract: A system for controlling door-mounted or door-embedded antennas. An antenna, for example, an EAS or an RF antenna, sends interrogation signals which are received by markers located on merchandise within a range of detection, i.e., an “interrogation zone”. Antennas that are mounted on or embedded in a door move along with the motion of the door. Thus, the interrogation zone covered by the antenna's magnetic field is continually changing with the movement of the door. The system and method of the present invention control door-mounted antennas by monitoring the motion of the door upon which the antenna is mounted, and by adjusting the size and breadth of the interrogation zone generated by the antenna accordingly.

Abstract: There is disclosed apparatus and methods for a directed energy beam virtual fence. The directed energy beam virtual fence may include a source unit to provide an energy beam and a sequence of relay units disposed at intervals along the length of the virtual fence. Each relay unit in the sequence may receive the energy beam from a previous unit and may recollimate and redirect the energy beam towards a subsequent unit.

Abstract: An intruder detection system is provided in which a detection range can be set to a predetermined one so that false detection caused by a moving object outside the predetermined range can be diminished. The system includes a transmission-side leaky transmission line that radiates a detection signal for detecting an intruder and a reception-side leaky transmission line that receives a detection signal leaked from the transmission-side leaky transmission line, both of which are buried spaced apart from each other in a detection surveillance area, and detects the presence/absence of an intruder in the detection surveillance area based on variations in the detection signal received by the reception-side leaky transmission line, wherein at least part of either the transmission-side leaky transmission line or the reception-side leaky transmission line is made of a surface-wave-type leaky coaxial transmission line, and the other leaky transmission line, a radiation-type leaky coaxial transmission line.

Abstract: In occupant detection systems, direct connections, such as fixed or permanent connections, are provided between the antenna and measurement circuit and between the measurement circuit and wiring harness. Multiple such arrangements may be used for capacitive, electric field, or other types of occupant detection circuits. In some embodiments, the occupant detection is split between a measurement circuit and a processor. For multiple sensors, multiple measurements circuits are provided with direction connections. The processor determines the occupancy state from data from the measurement circuits. The direction connections provide separate, unitary measurement modules to be used by the occupancy system.

Abstract: An ultrasonic transceiver device and remote output devices controlled by the transceiver for use by domestic pets. The transceiver utilizes a fixed interval edge detect modulation system to lock out stray environmental noise thereby, avoiding false triggering and greatly increasing the working range. Output devices include: a wireless pet containment system in which ultrasonic transmitters are mounted on a series of posts defining the perimeter of the containment area and a receiver device adapted to be worn by a domestic animal.