Abstract: In an embodiment, the present invention is a method for ranging which includes emitting an acoustic signal at a first frequency, monitoring for a first acoustic response signal at a second frequency, and responsive to receiving the first acoustic response signal within a predetermined amount of time, (1) calculating a first distance between a first device and a second device based on a duration between emitting the first acoustic signal and receiving the first acoustic response signal, and (2) broadcast a first message including the distance and an identifier.

Abstract: A serving system using a robot may include a caller mounted on each of a plurality of tables, and a robot driving to a target table among the plurality of tables based on information received from the caller, and the robot may store information on the location of each of the plurality of callers, the size and shape of each of the plurality of tables, the location of the caller mounted on the table, and the rotational angle with respect to a baseline of the caller, and the caller may transmit to the robot information on the distance from the caller to the robot and the direction of the robot with respect to the caller during driving of the robot.

Abstract: A method for determining position of an aircraft with reference to a location on the ground includes transmitting an acoustic signal from a position on the aircraft to an array of spaced apart acoustic sensors proximate the location. The method includes at least one of (i) determining a time difference of arrival of the acoustic signal between each of the acoustic sensors and a reference acoustic sensor and (ii) determining an arrival time of the acoustic signal at each of the spaced apart acoustic sensors. The position of the aircraft is determined from the time differences of arrival and/or the arrival times.

Abstract: The present group of inventions relates to methods and systems for positioning underwater objects, and more particularly to methods and systems in which satellite signals are received by receivers disposed on sonar buoys, the coordinates of the sonar buoys are determined by means of computation modules on the sonar buoys, location data and identification data are transmitted in the form of sonar signals emitted by transmitters on the sonar buoys, the signals are received with the aid of a receiver disposed on an underwater object, and the coordinates of the underwater object are determined according to the time delay of receipt of the sonar signals from the sonar buoys, the location of which is known. The present solution can be used in simultaneously determining the geographical position of an unlimited number of mobile underwater objects, remotely operated underwater vehicles, divers, marine animals, etc. in motion.

Abstract: A navigation system includes a support structure configured to be positioned at a sea floor. The navigation system also includes multiple transducers coupled to the support structure at fixed locations and configured to emit multiple reference signals. The navigation system further includes a transducer coupled to a movable subsea vessel and configured to receive the plurality of reference signals. A controller includes a processor and a memory, and the processor is configured to determine a position of the movable subsea vessel relative to the support structure based on the multiple reference signals.

Abstract: A method for locating a tool in a work space via ultrasound includes associating an ultrasound transmitter to a tool and calculating a position of the tool on the basis of determination of the position of the transmitter. At least three ultrasound receivers for receiving ultrasound signals from the transmitter are set in positions relative to the work space. A calculation of a position of the transmitter includes using a trilateration procedure that includes a change of reference of the positions of the receivers and is carried out to reference them in a second simplified reference system. An unknown point in the second simplified reference system is obtained. A rototranslation of the position of the unknown point obtained from the second simplified reference system is carried out into a first reference system, and a corresponding rototranslation matrix is calculated such that the unknown point is used as position of the transmitter.

Abstract: Devices and methods for aiding a large area search for submerged objects such as aircraft. A searcher transmits interrogation signals to be received by a device at the target object. The interrogation signals have a long range relative to that of returned signals. The target device responds with a ping signal modified to be more easily found by means of information contained in the interrogation signal. The information may be inherent in the nature of the received signal or data encoded and embedded by the searching device. The target device may use a microprocessor to do complex operations using the information from the interrogation signal and other information. Detection of a weak ping is facilitated by such means as being beamed in the direction of the interrogation, arriving at a predictable time, or having parameters adapted to values requested by the searcher.

Abstract: A system and method provides for one or more of tracking of an object and providing automatic access to applications or data. Depending upon the embodiment, the system includes a personal digital key (PDK), a reader, a computing device and one or more of an auto login server and a tracking server. The PDK stores one or more profiles in memory. A reader is configured to wirelessly communicate with the PDK. The computing device is coupled to the reader and one or more of the auto login server and tracking server. The auto login server is configured to communicate with the reader and launches one or more applications associated with a user name identified by a profile received from the PDK. The tracking server is configured to communicate with the reader and to track and log information received from the PDK associated with the object.

Abstract: A system for monitoring for gas and oil flow venting from a surface using time intervals, size and velocity, and using a processor with a data storage containing a bubble flow classification chart and bubble flow categories. The data storage receives at least one: video feed, drilling parameter data feed, seismic profile data feed, logging while drilling data feed, measurement while drilling data feed, sonar data feed, and hydrographic data feed to verify a determined bubble flow category and bubble flow classification as a baseline bubble flow classification and provides an alarm when a bubble flow emergency is ascertained due to a change in bubble flow classification without an anticipated change or changes outside predefined acceptable limits within the video feed, drilling parameter data feed, seismic profile data feed, logging while drilling data feed, sonar data feed, hydrographic data feed, or measurement while drilling data feed.

Abstract: The invention consists of a method which comprises a plurality of steps for determining difference in distance from a reference point to at least two sensor modules 10, 20 that are located under water. The sensor modules 10, 20 comprise means for sending and receiving acoustic signals to each other and to a hydrophone 30 at the reference point. Connected to the hydrophone 30 is a calculating unit 40 that utilises arrival time of the received signals from the sensor modules to determine difference in distance from the sensor modules 10, 20 to the reference point.

Abstract: Methods for personalized sound management are provided. A module comprising hardware and software is provided to manufacturers to build a device. A process is architected for remote enabling of a device with personalized sound management applications. Consumers select applications for managing their sound environment through purchased and subscription hardware and applications via a web environment. All products developed by manufacturers are tested and certified running the personalized sound management applications. Manufacturers and consumers may both be covered under liability insurance. Users may remotely purchase, update hardware, and add and download subscription based applications through the web environment.

Abstract: The invention consists of a method which comprises a plurality of steps for determining difference in distance from a reference point to at least two sensor modules 10, 20 that are located under water. The sensor modules 10, 20 comprise means for sending and receiving acoustic signals to each other and to a hydrophone 30 at the reference point. Connected to the hydrophone 30 is a calculating unit 40 that utilizes arrival time of the received signals from the sensor modules to determine difference in distance from the sensor modules (10, 20) to the reference point.

Abstract: In an embodiment a semiconductor device correlates a received signal with a known pattern. A correlation output is used as a basis for forming a confidence reference level. The confidence reference level and the correlation output are compared to identify a peak in the received signal indicating that a present signal state of the received signal contains the known pattern.

Abstract: A method, system, and apparatus for communicating data with a seismic sensor are provided. The method comprises identifying data to be transmitted and one or more seismic events that correspond to the data to be transmitted. One or more seismic events are created that are distinguishable into binary code from one or more seismic sensors within the array. Seismic events can be distinguished by their pattern or frequency. A first frequency can be assigned as a first binary code and a second frequency can be assigned as a second binary code. Likewise, different patterns of acoustic energy can designate different binary codes. Combinations of patterns and frequencies can be used together to create distinct distinguishable seismic events.

Abstract: An underwater location detection system comprising a number of acoustic reflectors at the location, wherein the acoustic reflectors emit acoustic signals in response to receiving an incoming acoustic signal. The frequency of the acoustic signal emitted by each of the acoustic reflectors is different from one another.

Abstract: A submarine homing system includes an acoustic emitter configured to emit an acoustic signal comprising at least two narrow-band tones, each narrow-band tone having a respective predetermined center frequency. An acoustic receiver is configured to receive the acoustic signal from the acoustic emitter, and produce one or more receiver signals. A processor is operatively connected to the acoustic receiver. The processor is configured to process the receiver signals to calculate a direction between the acoustic receiver and the acoustic emitter.

Abstract: A method and apparatus for an aircraft location system comprising an aircraft structure and a number of acoustic reflectors associated with the aircraft structure. The number of acoustic reflectors is configured to generate first sound signals in response to receiving second sound signals.

Abstract: Provided are an active radio frequency identification (RFID) system for port logistics and a communication method in the RFID system in which the forms of commands and response messages in the current standard are not changed in order to maintain compatibility with the current standard and to support multi-hop communication and some fields that are not generally used are used so as to enable communication between a tag in a shadow area and a reader by multi-hop communication using other surrounding tags.

Abstract: A system for automatically uploading a constellation module for a motion tracking system is provided comprising a programmable computer system having a first electronically readable storage medium. A motion tracking system is in communication with the programmable computer system, and includes a controller having a second electronically readable storage medium and a plurality of transponders. A configuration module resides on the first electronically readable medium. The configuration module is adapted to communicate with the motion tracking system and includes a first configuration parameter adapted to automatically instruct the second electronically readable storage medium to delete an existing constellation module, a second configuration parameter adapted to automatically acquire a desired replacement constellation module, and a third configuration parameter adapted to automatically transfer the replacement constellation module to the second electronically readable storage medium.

Abstract: A system for communicating information in a borehole between tool assemblies in a tool string includes receiving an information signal and separating a first signal that may be a power and low speed signal. A second signal is separated and demodulated from the information signal. The first signal and second signal are transmit to electronic devices that process data from an earth formation. After the first and second signals are transmit to one or more electronic devices, the signals are modulated and/or filtered and then combined into the information signal. The first signal is at one frequency and the second signal is at a different frequency. The apparatus includes a main signal line that couples to a second signal line and third signal line in the tool assembly.

Abstract: Connectors for joining adjacent modular floor covering units. Embodiments of the connectors include a film and an adhesive layer coated on one side of the film. The connectors can have a conductive component that allows electrical continuity to be maintained between adjacent tiles. In yet another embodiment, the connectors can be equipped as radio frequency identification tags by including radio frequency transponders. To install tiles using the connectors, a first tile is placed on the floor and a connector is positioned so that the adhesive layer faces upward and does not contact the floor. The connector is typically positioned so that only a portion of the adhesive layer adheres to the underside of the tile, leaving the remainder of the connector extending from the underside of the tile. One or more tiles are then positioned adjacent the first tile so that a portion of the connector adheres to the adjacent tiles. In this way, the connectors span adjacent tile edges.

Abstract: A system for precise positioning of subsea units has a remotely operated vehicle, an inertial measurement unit positioned on the vehicle so as to produce a signal relative to a position of the subsea unit, a doppler velocity log coupled to the vehicle in producing a signal relative to the position of the subsea unit, a baseline measurement device coupled to the vehicle and producing a signal relative to the position of the subsea unit, a Kalman filter cooperative with the signals from the inertial measurement unit and the doppler velocity log and the baseline measurement device, and a processor cooperative with the Kalman filter for producing an output indicative of the positioning of the subsea unit. A doppler velocity log includes a plurality of beams which are individually connected to the Kalman Filter.

Abstract: A system for communicating information in a borehole between tool assemblies in a tool string includes receiving an information signal and separating a first signal that may be a power and low speed signal. A second signal is separated and demodulated from the information signal. The first signal and second signal are transmit to electronic devices that process data from an earth formation. After the first and second signals are transmit to one or more electronic devices, the signals are modulated and/or filtered and then combined into the information signal. The first signal is at one frequency and the second signal is at a different frequency. The apparatus includes a main signal line that couples to a second signal line and third signal line in the tool assembly.

Abstract: One aspect of the invention is a system for locating an object. The system may include, for example, an object electromagnetic receiver, an audio amplifier, an audio transducer, and an object microprocessor coupled to the object electromagnetic receiver and the audio amplifier. The object microprocessor is configured to ascertain whether a valid activation signal has been received by the object electromagnetic receiver, and if so, read a digital sound file, and ascertain whether the signal strength of the received valid activation signal is above a first threshold. If the signal strength is not above the first threshold, the object microprocessor outputs a maximum sound level indicator signal; and if the signal strength is above the first threshold, the object microprocessor outputs a second tier sound level indicator signal.

Abstract: Systems and methods for determining the position of a component rack within a data center and/or the positions of components within the component rack. In one embodiment, a plurality of ultrasonic reference transponders are disposed in fixed locations throughout a data center. The reference transponders communicate with one another to establish a reference coordinate system for the data center. Each component rack in the data center is provided with an ultrasonic rack transponder that can be triangulated with the reference transponders to determine the position of a component rack. This “rack position” information can be used by a system controller to control the components and to help regulate the data center within pre-specified operating parameters. If a problem occurs in the data center, information about the position of the affected components and component racks may be used by the system controller or a system administrator to help remedy the problem.

Abstract: The invention relates to an identification chip for insertion in an object located in a liquid. The identification chip comprises an acoustic resonator (100), which exhibits a number of distinct resonant frequencies, where the combination of resonant frequencies is unique to the identification chip. This enables the identification chip to be identified by exposing it to an acoustic polling signal, measuring an acoustic response signal and analysing the frequency of the response signal. The resonator (100) comprises a cavity-forming part (110, 120) and a membrane (130). The acoustic resonant frequencies are determined by at least one cavity (140), which is enclosed by the cavity-forming part (110, 120) and the membrane (140). The identification chip can be implanted in a fish, with the object of identifying the fish when it is located in water.

Abstract: A Write Broadcast system and method uses a base station to write sent data to all or some selected number (sub group) of tags in a base station field simultaneously. By unselecting the tags that have been successfully written to, and requesting a response from the remaining tags in the field (or sub group), the system determines, by receiving a response to the request, that there are tags in the field (sub group) that were unsuccessfully written to. Another Write Broadcast signal is sent to these tags. The system is useful for quickly (simultaneously) “stamping” information on the tag memory of a large number of tags in the field of the base station.

Abstract: A Write Broadcast system and method uses a base station to write sent data to all or some selected number (sub group) of tags in a base station field simultaneously. By unselecting the tags that have been successfully written to, and requesting a response from the remaining tags in the field (or sub group), the system determines, by receiving a response to the request, that there are tags in the field (sub group) that were unsuccessfully written to. Another Write Broadcast signal is sent to these tags. The system is useful for quickly (simultaneously) “stamping” information on the tag memory of a large number of tags in the field of the base station.

Abstract: A two-way ultrasonic positioning and navigation system and method involve a plurality of objects each capable of transmitting and receiving ultrasonic signals. A first object transmits an initiating ultrasonic signal and identifies a second object for responding to the initiating ultrasonic signal. The second object transmits a responding ultrasonic signal after a predetermined time delay from receiving the initiating ultrasonic signal. The first objectives the responding ultrasonic signal, and determines a distance between the first object and the second object based on a time period starting at the transmission of the initiating ultrasonic signal and ending at the reception of the responding ultrasonic signal, and on knowledge about the predetermined time delay and other known in advance time delays.

Abstract: The invention relates to a method for recognition, determination and localisation of at least one arbitrary object or space and the picking up of said object, by means of at least one robot, in particular, a service robot, which operates independently on a base surface. Said method is achieved, whereby the robot is orientated within at least one room by means of room co-ordinates and/or co-ordinates of arbitrary objects in the room, transmitted to the robot by means of at least one sensor element, in particular, a transponder or transmitter.

Abstract: An electroacoustic transducer comprising a magnetic circuit of a magnetically conductive material with a pair of opposed surfaces defining a gap therebetween, the magnetic circuit comprising a magnet inducing a magnetic field in the gap, the magnet having a surface constituting one of the opposed surfaces. The magnetic circuit further comprises a diaphragm and a coil having electrically conducting paths secured to the diaphragm. The coil has portions of its paths situated in the gap.

Abstract: A dipping sonar transducer housing includes a generally cylindrical housing (10) which is suspended at the end of a cable (12) connected to tile housing through a vibration isolation module (14) which includes springs (22) to damp out noise, particularly that from the supporting vehicle. The housing (10) contains an upper water-tight chamber (26) which contains circuit boards (28) and preamplifiers (30) which serve as amplification and multiplexing means for the hydrophones carried on extendible arms (96, 60, 88); a second water-tight chamber (35) immediately below the first chamber (26) contains an electric motor (36) which drives a hydraulic pump (38) which provides fluid under pressure to an accumulator (40). Movable vertically on the outside of the second chamber (35) is a piston (48) which drives a plurality of links (54, 56) which extend the receiver array.

Abstract: A system, apparatus, and method for determining positions of underwater animals involves emplacement of an acoustic transponder on the animal and establishing communications with a transponder carried by a vessel whose position can be determined by receiving signals from an external source such as a GPS satellite in order to establish proximity of the animal to the vessel, the position of the vessel then being adopted as the position of the animal. Communications can be established either by communicating the position of the transceiver to the equipment on the animal for storage therein, or by communicating the identity of the animal to the vessel whose position has been determined for association with the position, and subsequent local storage on the vessel and/or communication to a central station.

Abstract: A Write Broadcast system and method uses a base station to write sent data associated with no particular destination tag or tags, by radio frequency signal, to all or some selected number (sub group) of tags in a base station field simultaneously. By unselecting the tags that have been successfully written to, and requesting a response from the remaining tags in the field (or sub group), the system determines, by receiving a response to the request, that there are tags in the field (sub group) that were unsuccessfully written to. Another Write Broadcast signal is sent to these tags. The system is useful for quickly (simultaneously) "stamping" information on the tag memory of a large number of tags in the field of the base station.

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.

Abstract: A transponder has a resonant RLC circuit with one or more electromagnetic energy storage components that vary in response to an externally applied modulating energy field. In addition to the externally modulating energy field, a base station transmits a carrier signal with a frequency essentially the same as the quiescent resonant frequency of the RLC circuit. As the component(s) vary, the resonant frequency of the RLC circuit changes, modulating the carrier signal with the external modulating energy field. Effects of the modulation are detected by the base station. Information (e.g., the presence of a tag) is obtained by receiving and demodulating the modulated signal at the base station. One or more of the circuit elements (e.g., different preferred embodiments of one or more capacitors, inductors, and resistors) can be varied (e.g. mechanically) to modulate the carrier signal.

Abstract: An acoustic tomography telemetry system and method allowing spatially averaged ocean temperatures to be measured in real-time. The system includes autonomous acoustic sources mounted on subsurface moorings and receivers that are either suspended from drifting surface buoys or cabled to shore. The telemetry method largely eliminates, in real-time, corruption of acoustic travel times due to wander of the source's mooring by shifting the start times of tomographic transmissions. Corrections to source wander are obtained without expending battery energy over and above that used in conventional tomography experiments. Standard techniques are used to correct clock errors at the source in real-time.

Abstract: A performer tracking system, and an associated method, for tracking movements of at least one performer upon a stage. A plurality of signal transmitters are positioned about the stage and transmit electromagnetic signals. Performers on the stage carry transponders which receive the electromagnetic signals and, responsive thereto, generate coded sound signals. Sound signal receivers positioned together with the signal transmitters receive the sound signals. A controller determines positions of the transponders and, hence, the performers carrying the transponders and causes spotlights to track the performers.

Abstract: One or more slave acoustic transponders are secured to selected parts of a seismic bottom cable whose location is imperfectly known. A master transponder broadcasts an interrogation pulse from each of a number of different, known locations distributed along a line of survey. In response to an interrogation pulse, a slave transponder emits an encoded signal that is received by the master transponder. The acoustic flight time between each pulse broadcast and encoded-signal reception constitutes a range measurement to the participating slave transponder. Resolving a gather of several range measurement from different known broadcast locations, focussed on an identifiable transponder, defines the transponder location.

Abstract: A transponder of an active digital sonar system identifies a multifrequency underwater activating sonar signal received from a remote sonar transmitter. The transponder includes a transducer that receives acoustic waves, including the activating sonar signal, and generates an analog electrical receipt signal. The analog electrical receipt signal is converted to a digital receipt signal and cross-correlated with a digital transmission signal pattern corresponding to the activating sonar signal. A relative peak in the cross-correlation value is indicative of the activating sonar signal having been received by the transponder. In response to identifying the activating sonar signal, the transponder transmits a responding multifrequency sonar signal.

Abstract: A remotely controlled radio telemetry buoy serves as a communication link tween an underwater acoustic interrogation/receiving transponder system and a remotely located surface platform. The buoy houses a transmission device, a transceiver device and a controller. The transmission device transmits data received from the transponder system as electromagnetic energy in a frequency range of 162-173 MHz. The transceiver device exchanges digital control signals between the surface platform and the buoy in the frequency range of 2-16 MHz. The controller transfers the control signals between the transceiver device and the transmission device and the transponder system.

Abstract: A method for reliably locating the position of a submerged submarine with spect to a surface ship. A multiple number of transponders are placed at known locations near the sea floor, in the area of the ship and the submarine. One transponder has a dual function both as a response transponder and as a relay transponder. The other transponders have a single function as response transponders. Elapsed times between transmission of a first acoustic transmission pulse from the ship and receptions of first acoustic response pulses coming from the transponders, are measured at the ship. Elapsed times between transmission of a second acoustic pulse from the ship, its relay through the relay transponder, a response to the relayed signal by the submarine and then responses to the submarine's response pulse by the transponders, are also measured at the ship. These elapsed times are used to determine distances between the ship and the transponders, and distances between the transponders and the submarine.

Abstract: A monitoring device for portable breathing apparatuses having a manometer by means of which the pressure in the pressure container of the breathing apparatus is detected, and having a transmitter by means of which a signal corresponding to the pressure is transmitted at regular intervals. The transmitter also has a signal generating device which generates an identification signal which is characteristic of the transmitter. The pressure signal and identification signal are received and tested by a receiver. If the identification signal matches an identification comparison signal stored in the receiving device, the measured pressure value is displayed on a display device.

Abstract: An object locating system, especially for use in locating a gaming ball in the game of football, utilizes a series of three sensors positioned on one side of a football playing field and a calibration source positioned on the other side. The calibration source emits an ultrasonic signal which is received by the sensors in order to provide a calibration signal. A ball marking unit is positionable on the field at a location of the ball and emits an ultrasonic signal which is received by the sensors and an RF signal which is received by the calibration source in order to turn the calibration source off. The sensors provide signals in which a processing unit calculates time delays by a time acquisition process in order to determine the position of the ball. In an alternate embodiment, the ball marking unit emits only an RF signal which is received by the sensors. The sensors again provide signals which are analyzed by the processing unit to determine delay between receipt of the signals at the sensors.

Abstract: The positions of one or more underwater divers or vehicles are determined through an underwater acoustic communication link and at least a base buoy and one remote buoy with acoustic transponders and GPS position locating equipment. The location of the buoys is determined by the GPS equipment. The underwater diver or vehicle each carries an acoustic tracking unit transponder which emits a tracking unit message specifying its identity and its last known position at an assigned time slot. Upon reception of the tracking unit message by the base buoy, an acoustic base buoy message is emitted which includes the buoy position. The tracking unit receives the base buoy message, and marks the time of arrival to determine the propagation delay between the tracking unit and the base buoy. A predetermined delay after the receipt of the tracking unit message by the remote buoy, it sends an acoustic remote buoy message specifying its location.

Abstract: An underwater location system (16) is disclosed having a plurality of locator modules (18), each capable of finding the relative range and bearing of other modules. The modules may be diver mounted, placed on movable objects such as a boat (14) or on fixed positions such as the sea floor (12). Range and bearing to each module of the system is displayed, upon request, on a console (20) which may be hand held or mounted in a diver's instrument console. Each module can interrogate other modules with an acoustic pulse which is answered, after a unique time delay stored in each module, by an acoustic response pulse. Response pulse sources are identified by their arrival in a time detection window set by their unique time delay. Range to each identified transponder source is calculated from a receipt time within each detection window.

Abstract: Apparatus for sensing distances between two objects by using multiple pulses from the detector and from the object to be detected by using a transmitter and not using any reflected waves the reliability and the ability to reject clutter is improved. The periods between transmission are accurately controlled so that there is no signal returned until the object to be detected generates such a signal. As a result it is possible to accurately measure the distance between two objects and indeed the system may be used between two objects when both are in motion.

Abstract: An acoustic data acquisition system for shipboard use is disclosed that allows for underwater acoustic data measurements at preselected submerged marine structural coordinates using a free swimming, quiet dynamically positionable remotely operated vehicle (ROV). Moreover, the disclosure provides a method of performing acoustic data acquisition with an ROV by first inputting the marine structural features by use of a computer aided design subsystem, determining the required trajectory path and hovering coordinates for data measurements, next, establishing the acoustic telemetry system for the remotely operated vehicle's control system to operate within and make an absolute positional fix to the marine structure's coordinates then, establish the ambient acoustic conditions of the worksite. The system is monitored and controlled from a computer based system.

Abstract: A position and velocity determining system, that uses two functioned receiver-transmitters. In performing a first function, each receiver-transmitter transmits an acoustic pulse at a unique frequency, in response to a first received accoustic pulse. In performing a second function, each receiver-transmitter transmits a continuous acoustic signal at a unique frequency, in response to a second received acoustic pulse.

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.