Abstract: A gunshot location system computes candidate gunshot locations from angle-of-arrival information and time-of-arrival information provided by acoustic sensors. In addition to an angle, each sensor calculates an angular uncertainty from impulses received at four or more microphones having rotational symmetry. An intersection of one or more time-of-arrival hyperbolas with one or more angle-of-arrival beams is used to determine a candidate gunshot location. In simple environments, a location can be confirmed with just two sensors allowing sensor density to be significantly reduced, while in complex environments including reflections, blocking, and interfering acoustic events, the additional angle-of-arrival information improves location accuracy and confidence, allowing elimination of candidate locations inconsistent with the combined time-of-arrival and angle-of-arrival information.

Abstract: Methods and systems are provided herein for signal source tracking. A signal emitted over time from a moving source is a collection of small sub-signals that were emitted by the source at different positions along its path. If the source is traveling at a slower speed than the signal, the sub-signals will arrive at a given sensor in the same order that they were released. By identifying the locations and times of the releases of several of these sub-signals, the path and velocity of the moving source can be estimated.

Abstract: Systems and methods for locating the shooter of supersonic projectiles are described. The system uses at least five, preferably seven, spaced acoustic sensors. Sensor signals are detected for shockwaves and muzzle blast, wherein muzzle blast detection can be either incomplete coming from less than 4 sensor channels, or inconclusive due to lack of signal strength. Shooter range can be determined by an iterative computation and/or a genetic algorithm by minimizing a cost function that includes timing information from both shockwave and muzzle signal channels. Disambiguation is significantly improved over shockwave-only measurements.

Abstract: A target for a test range includes an impact plate having at least three strain sensors positioned on the plate. The sensors are connected to a data acquisition board for receiving a signal from each sensor upon impact of a projectile on the plate. The data acquisition board is joined to a processor for calculating impact location and energy. Optionally multiple sensors can be provided having different orientations for accounting for different strain components in the plate.

Abstract: Localization of remote devices by: the emission of pulses from acoustic transmitters, whose wavefronts propagate in the space region occupied by the remote devices and finally reach them; the emission of radiofrequency pulses from each remote device at the time of detection of the wavefront by an on-board microphone; the acquisition, by a radio base, of the radiofrequency signals propagating from the remote devices, to evaluate the arrival time delays proportional to the distance between the i-th acoustic source and the j-th remote device; the formation of a reception vector for each emission by the i-th source, this vector having a maximum length M equal to the number of remote devices and consisting of the sequence of distances obtained as the product of the reception times and the estimated sound velocity. These steps are repeated for all acoustic sources, to form N+1 reception vectors, to calculate the position of the device by solving derived matrix equations.

Abstract: A vehicle crash event is detected and characterized based on the transmission of acoustical shear waves through the vehicle frame. At least three, and preferably four or more, acoustical emission sensors longitudinally and laterally distributed on the vehicle frame produce acoustical signals that are processed to extract the shear wave energy due to impacts. Since shear waves are non-dispersive and travel through the vehicle frame at a known velocity, they can be detected in any part of the frame. The extracted shear wave signals are used not only to judge the severity of the impact, but also to characterize the type of crash and determine the direction of the impact based on when the shear wave is detected by each of the acoustical emission sensors.

Abstract: An apparatus and method is disclosed for determining the position of a user interface mouse using time of arrival measurements. A transmitter transmits a signal to an array of receivers that are spatially separated from one another. The time difference of arrival for is found for each receiver relative to a predetermined reference receiver. Using the time difference of arrival (TDOA) of each receiver, the location in 3-dimensional space of each receiver, and the speed of sound the position of the transmitter in 3-dimensional space relative to the reference receiver may be found.

Abstract: A method and apparatus for determining the position of an object relative to a moving vehicle. While the vehicle is moving in a first direction, successive sensor pulses are transmitted from a vehicle sensor and toward the object. The echo or reflection from the sensor pulse is then received while a processor determines the transit time between the transmission of each pulse and the receipt of its echo. An angle factor is then calculated which represents the difference between the elapsed time of two sequential sensor pulses and the distance traveled by the vehicle between those two pulses. Whenever the absolute value of the angle factor exceeds a preset threshold, an angle is selected from a predefined lookup table contained in memory. Conversely, when the absolute value of the factor is less than the preset threshold, the angle is calculated as a function of the factor.

Abstract: A method and system for determining the position of a vehicle comprises a transmitter or transceiver for transmitting a transmission signal from a vehicle to beacons associated with the work area. A data processor determines an elapsed time including at least one of a first propagation duration and a second propagation duration. The first propagation duration refers to a propagation time of the transmission signal from the vehicle to the particular beacon; the second propagation duration refers to a propagation time of a return signal from the particular beacon to the vehicle. A compensator compensates for the following associated with the transmitter and the particular beacon: bias delay, noise, and measurement error. A data processor processes the elapsed times into corresponding position curves or temporal curves to estimate a position of a vehicle at a confluence or intersection of the position curves or temporal curves.

Abstract: An acoustical positioning system for positioning a portable electronic device including a loudspeaker system including three or more loudspeakers and a control unit operable according to a first time reference wherein the control unit controls the transmission of a series of audio beacons from the loudspeakers, wherein a first beacon is transmitted at a first time of the first time reference from a first speaker, a second beacon is transmitted at a second time of the first time reference from a second speaker, and a third beacon is transmitted at a third time of the first time reference from a third speaker; at least one portable electronic device operable according to a second time reference and including a synchronizer for synchronising the second time reference to the first time reference; a microphone for receiving the transmitted series of audio beacons; a detector for detecting the time according to the second time reference at which an audio beacon is received and for identifying the origin of the rece

Abstract: An apparatus and a method for detecting a position of a mobile robot in accordance with the present invention can accurately detect a position of a mobile robot by calculating time taken for each ultrasonic signal generated by ultrasonic signal oscillating means of a charging station to reach the mobile robot on the basis of a point of time at which an RF (Radio Frequency) signal emitted from the mobile robot is generated; calculating a distance between the charging station and the mobile robot based on the calculated reaching time; and calculating an angle between the charging station and the mobile robot based on the calculated distance value and a preset distance value between the ultrasonic signal oscillating means.

Abstract: In a building environment, a distance associated with a building automation device is determined as a function of an interval or an inserted time delay between a wireless transmission of a signal and wireless reception of another signal. For example, a two-way communication is provided with an automatic interval or a desired time delay inserted before responding to a received transmission. By using two-way transmissions, the building automation devices may be free of clock synchronization. Acoustic signals may be used in a building environment to determine a distance. The building automation device may also use radio frequency information for communicating with other devices.

Abstract: A thermometer and extensometer for cables and conductors is described. The travel time of one or more acoustic signals along a conductor is used to determine the temperature along the conductor and the length of the conductor. The acoustic frequency is selected to minimize temporal dispersion of the propagating acoustic energy. The technique can be used to measure the temperature of the conductor in a buried, undersea or submerged electrical power cable.

Abstract: A thermometer and extensometer for cables and conductors is described. The travel time of one or more acoustic signals along a conductor is used to determine the temperature along the conductor and the length of the conductor. The acoustic frequency is selected to minimize temporal dispersion of the propagating acoustic energy. The technique can be used to measure the temperature of the windings in a transformer or other electrical apparatus.

Abstract: To measure an accurate positional relationship between an ultrasonic tag and a microphone and identify a sound source position, even if an object is present between the ultrasonic tag and the microphone. When a radio transmission unit transmits a radio wave, an ultrasonic wave transmission unit of an ultrasonic tag receives it and transmits an ultrasonic wave. Then, a plurality of microphones in an ultrasonic wave reception array unit receive the ultrasonic wave. A propagation time calculation unit calculates a time from when the radio wave is transmitted by the radio transmission unit till when an ultrasonic wave reaches each of the microphones in the ultrasonic wave reception array unit. A position estimation unit calculates the position (sound source) of the ultrasonic tag according to the arrival time at each of the microphones and the result of object detection while considering reflection of the ultrasonic wave.

Abstract: The present invention relates to systems and methods of tracking and/or avoiding harm to certain devices or humans. According to one exemplary embodiment, a method of tracking individual assets may include obtaining position data of an asset via a GPS receiver in communication with a position sensor associated with the asset, processing position data and sensor data via a processing component associated with the position sensor that receives the position data from the GPS receiver, and communicating sensor data to a host device via a communication interface associated with the position sensor and configured to enable wireless communication between the position sensor and the host device.

Abstract: A system for determining the position of an object (8) in a space (10) defined by surfaces (11, 12) comprises at least a first transducer (1), a second transducer (2) and a processing device. The transducers are arranged at a mutual spacing (D). The processing device is arranged for determining the times of arrival of both acoustic signals transmitted between the object and each of the transducers (1, 2) and their reflections. On the basis of the difference in the times of arrival of clusters of acoustic signals and the associated reflections the processing device can determine which surface (11, 12) the indirect acoustic signals were reflected by, thus providing additional position information.

Abstract: A gunshot location system computes candidate gunshot locations [314] from angle-of-arrival information [304, 308] and time-of-arrival information [312] provided by acoustic sensors [300, 302]. In addition to an angle, each sensor calculates an angular uncertainty [306, 310] from impulses received at four or more microphones having rotational symmetry. An intersection of one or more time-of-arrival hyperbolas with one or more angle-of-arrival beams [322] is used to determine a candidate gunshot location. In simple environments, a location can be confirmed with just two sensors allowing sensor density to be significantly reduced, while in complex environments including reflections, blocking, and interfering acoustic events, the additional angle-of-arrival information improves location accuracy and confidence, allowing elimination of candidate locations inconsistent with the combined time-of-arrival and angle-of-arrival information.

Abstract: A system and method for detecting, identifying, and fixing the location of the source of an acoustic event. The inventive system includes: a plurality of sensors dispersed at somewhat regular intervals throughout a monitored area; a communication network adapted to deliver information from the sensors to a host processor; and a process within the host processor for determining, from the absolute times of arrival of an event at two or more sensors, a position of the source of the event. Acoustic events are detected and analyzed at each sensor so that the sensor transmits over the network: an identifier for the sensor; an identifier for the type of event; and a precise absolute time of arrival of the event at the sensor. In a preferred embodiment, the system also identifies the type of weapon firing a gunshot.

Abstract: A method for determining position of a mobile electronic device includes emitting an acoustic pulse from the position of the mobile electronic device. The acoustic pulse is detected at a known position at three spaced apart locations along each of at least two lines extending in different directions. The range and phase difference of the acoustic pulse between each of the detecting locations is determined. A relative position of the device with respect to the known position is obtained from the range and phase differences.

Abstract: A thermometer and extensometer for cables and conductors is described. The travel time of one or more acoustic signals along a conductor is used to determine the temperature along the conductor and the length of the conductor. The acoustic frequency is selected to minimize temporal dispersion of the propagating acoustic energy. The technique can be used to measure the temperature and sag of an overhead power line, the temperature of the windings in a transformer, or the temperature of the central conductor in a coaxial power cable.

Abstract: A method for determining the position of an underwater device includes placement of a plurality of station keeping devices on or below the surface of the water in known positions. A device to locate is provided for placement below the surface of the water, and the device to locate and the station keeping devices are provided with a synchronized time base and a common acoustic pulse time schedule. Each station keeping device sends an acoustic pulse at a time according to the common acoustic pulse schedule. The device to locate receives pulses sent by the station keeping devices and calculates a distance between itself and each station keeping device based upon the time that the acoustic pulse is sent and the time that the pulse is received. The device to locate then calculates its position based upon the distances between the device to locate and the station keeping devices. Systems and devices are also disclosed.

Abstract: A method of locating an acoustic source, the method comprising sampling said acoustic source at a plurality of acoustic receivers having different locations, each acoustic receiver time-stamping a respective received acoustic sample using a system time, each acoustic receiver sending said time-stamped acoustic sample to a central controller, the central controller determining the location of the acoustic source in response to receiving the time-stamped sound source samples from the plurality of receivers.

Abstract: A system comprises a plurality of seismic transmitters, at least one seismic source array, and a processor. Each seismic source array comprises a plurality of seismic source-array elements, mounted within the seismic source array; and a plurality of near-field sensors, wherein each near-field sensor is mounted within the seismic source array in the vicinity of one of the seismic source-array elements. The processor is adapted to determine relative positions of the seismic source-array elements on the seismic source array from the seismic signals transmitted by the seismic transmitters and received at the near-field sensors on the seismic source array.

Abstract: Systems and method are disclosed for processing signals. In one exemplary implementation, a method may include transforming initial bullet data associated with one or more sensors into a set of discrete pulses, dividing the discrete pulses into pulse subsets, generating, for the subsets, time domain representations of the pulses, wherein the time domain representations include waveforms having pulse features, and processing the time domain representations to determine alignment between one or more of pulse features, pulses, pairs of channels, and/or pairs of sensors. One or more further implementations may include determining identity of pulses in association with a matching process performed as a function of the alignment, as well as, optionally, other pulse processing features/functionality.

Abstract: The present invention provides a system for identifying and locating an acoustic event. In a preferred embodiment a gunshot detection sensor includes an audio sensor which detects gunshots in combination with a GPS engine which provides location and timing in conjunction with a host system. This allows an acoustic sensing weapon locator which is integrated for size and portability. The inventive mobile military gunshot detector requires a battery or fuel cell at its heart to operate. By managing the power consumption, batteries can be down-sized and the time between changes or recharges can be dramatically extended allowing soldiers to carry less weight and transport fewer replacement batteries into a hostile environment.

Abstract: In a positional information detecting device, a tone-burst signal propagating unit causes a tone-burst signal to propagate through a path. The tone-burst signal is composed of a continuous wave train, the continuous wave train including a plurality of cycles of a constant frequency. A detecting unit detects, at a predetermined position in the path, the tone-burst signal propagating through the path every one cycle of the tone-burst signal to measure a propagation delay time based on the detected signal. The propagation delay time represents a period for which the tone-burst signal has propagated through the path. A phase obtaining unit obtains a phase of the detected signal. A positional information obtaining unit obtains positional information associated with the predetermined position based on the measured propagation delay time and the obtained phase of the detected signal.

Abstract: The present invention relates to an input apparatus, and more particularly, to an information input apparatus and position recognition apparatus using an ultrasonic wave. The information input apparatus includes an input unit for generating an ultrasonic signal and a receiver for receiving the ultrasonic signal generated in the input unit, wherein the input unit includes ultrasonic generator for generating an ultrasonic signal according to a movement of the input unit, and a controller for generating a control signal to enable the ultrasonic generator to generate the ultrasonic waves, the receiver includes an ultrasonic receiver for receiving the ultrasonic signal generated in the ultrasonic generator, and a signal processor for performing a signal processing in a phase sensitive cross-correlation scheme in order to track the position of the input unit using the ultrasonic signal received in the ultrasonic receiver.

Abstract: A method and apparatus for measuring a distance to a sound source. The method includes combining sound source signals input through at least two microphones and generating at least two microphone output signals, and performing an operation on the generated microphone output signals and calculating a distance to a sound source by using the relationship between a result of the operation and a frequency of the input sound source signals. Accordingly, regardless of the strength of a sound source, the distance to a sound source can be measured.

Abstract: The delay between two signals is determined by obtaining zero crossings from each signal, and using each crossing to trigger the sampling of the other signal. Two samples are taken in response to each zero crossing, and the difference between those two samples is calculated. This difference is summed for each event and both signals to derive a value. The process is repeated for different delays between the first and second signals. The values are examined to determine the delay which corresponds to the greatest coincidence between the signals.

Abstract: A method for determining the position of an underwater device includes placement of a plurality of station keeping devices on or below the surface of the water in known positions. A device to locate is provided for placement below the surface of the water, and the device to locate and the station keeping devices are provided with a synchronized time base and a common acoustic pulse time schedule. Each station keeping device sends an acoustic pulse at a time according to the common acoustic pulse schedule. The device to locate receives pulses sent by the station keeping devices and calculates a distance between itself and each station keeping device based upon the time that the acoustic pulse is sent and the time that the pulse is received. The device to locate then calculates its position based upon the distances between the device to locate and the station keeping devices. Systems and devices are also disclosed.

Abstract: A navigation device for navigating a user interface of a processor-controlled device includes an acoustic transmitter adapted to transmit an acoustic signal, an acoustic receiver adapted to receive the acoustic signal and located at a fixed position with respect to the acoustic transmitter, and a measurement circuit coupled to an output of the acoustic receiver and adapted to determine a distance traversed by the navigation device as a function of time.

Abstract: An acoustic detection and localization system includes a signal acquisition stage, a biomimetic processor, and an acoustic feature processor. The system uses multiple acoustic cues including spectral content, inter-aural time delay (ITD), inter-aural intensity difference (IID), and periodicity content to detect, classify, and localize sound sources. Pairs of acoustic sensors are arranged geometrically with a spacing depending on the application. The biomimetic processing provides for echo suppression to enhance performance in reverberant environments, and automatic gain controls for robustness in noisy environments. Applications include mobile robotic platforms for reconnaissance and surveillance, helmet mounted systems for sniper detection, vehicle-mounted systems for combat awareness, general civilian security systems, and systems for environmental monitoring and tracking of animals.

Abstract: One or more embodiments of the present invention are aimed at a device for ships, in particular for multihull ships and high-speed multihull ships making it possible to avoid obstacles, in particular obstacles submerged at low depth. In at least one embodiment, the device according to the invention comprising at least: two transmitters of acoustic waves spaced apart from one another and transmitting waves of distinct frequencies or of different waveforms, an acoustic receiver, whose reception band is suitable for the emission frequencies of the transmitters, means of processing of the received signals, these means performing, through the echoes received, a measurement of the difference of the propagation times and a measurement of the differential Doppler frequency of the waves transmitted by each of the transmitters; these processing means thus determining from these measurements the position of and object having returned an echo.

Abstract: Provided are a positioning system using ultrasonic waves and a method for controlling the positioning system. The method for controlling a positioning system installs a plurality of ultrasonic satellites generating ultrasonic signals to position a mobile. The method sequentially gives satellite identification numbers to the plurality of ultrasonic satellites, generates a synchronization signal and providing it to the plurality of ultrasonic satellites, and allows the mobile to receive ultrasonic signals, which are generated by the plurality of ultrasonic satellites in the order of the satellite identification numbers when the ultrasonic satellites receive the synchronization signal, to measure distances between the mobile and the ultrasonic satellites.

Abstract: A gunshot location system computes candidate gunshot locations [314] from angle-of-arrival information [304, 308] and time-of-arrival information [312] provided by acoustic sensors [300, 302]. In addition to an angle, each sensor calculates an angular uncertainty [306, 310] from impulses received at four or more microphones having rotational symmetry. An intersection of one or more time-of-arrival hyperbolas with one or more angle-of-arrival beams [322] is used to determine a candidate gunshot location. In simple environments, a location can be confirmed with just two sensors allowing sensor density to be significantly reduced, while in complex environments including reflections, blocking, and interfering acoustic events, the additional angle-of-arrival information improves location accuracy and confidence, allowing elimination of candidate locations inconsistent with the combined time-of-arrival and angle-of-arrival information.

Abstract: Acoustic ranging may involve determining a distance between a first device and at least one other device using one or more acoustic signals. In an example embodiment, a first device emits a first acoustic signal and then receives the first acoustic signal at a first time. The first device also receives a second acoustic signal at a second time, with the second acoustic signal having been emitted by a second device. The first device ascertains a first value that reflects a difference between the first time and the second time. Responsive to at least the ascertained first value, the first device determines a distance between the first device and the second device.

Abstract: A system and method for detecting, identifying, and fixing the location of the source of an acoustic event. The inventive system includes: a plurality of sensors dispersed at somewhat regular intervals throughout a monitored area; a communication network adapted to deliver information from the sensors to a host processor; and a process within the host processor for determining, from the absolute times of arrival of an event at two or more sensors, a position of the source of the event. Acoustic events are detected and analyzed at each sensor so that the sensor transmits over the network: an identifier for the sensor; an identifier for the type of event; and a precise absolute time of arrival of the event at the sensor. In a preferred embodiment, the system also identifies the type of weapon firing a gunshot.

Abstract: A noise control system is provided for controlling a noise level around a moveable target. The noise control system has a detecting system configured to detect a location and movement of the target, and a noise cancellation system. The noise cancellation system has a sensor for dynamically sensing noise at the location of the target. The noise cancellation system is configured to be responsive to detection of the location of the target by the detecting system and the sensed noise to provide a noise cancellation wave to a first space at and around the location of the target. The noise cancellation system is further configured to be responsive to detection of the movement of the target by the detecting system and the sensed noise, and to provide a noise cancellation wave to a second space to cover the moving target. The second space is larger than the first space.

Abstract: A gunshot location system computes candidate gunshot locations [314] from angle-of-arrival information [304, 308] and time-of-arrival information [312] provided by acoustic sensors [300, 302]. In addition to an angle, each sensor calculates an angular uncertainty [306, 310] from impulses received at four or more microphones having rotational symmetry. An intersection of one or more time-of-arrival hyperbolas with one or more angle-of-arrival beams [322] is used to determine a candidate gunshot location. In simple environments, a location can be confirmed with just two sensors allowing sensor density to be significantly reduced, while in complex environments including reflections, blocking, and interfering acoustic events, the additional angle-of-arrival information improves location accuracy and confidence, allowing elimination of candidate locations inconsistent with the combined time-of-arrival and angle-of-arrival information.

Abstract: A system and method for detecting, identifying, and fixing the location of the source of an acoustic event. The inventive system includes: a plurality of sensors dispersed at somewhat regular intervals throughout a monitored area; a communication network adapted to deliver information from the sensors to a host processor; and a process within the host processor for determining, from the absolute times of arrival of an event at two or more sensors, a position of the source of the event. Acoustic events are detected and analyzed at each sensor so that the sensor transmits over the network; an identifier for the sensor; an identifier for the type of event; and a precise absolute time of arrival of the event at the sensor. In a preferred embodiment, the system also identifies the type of weapon firing a gunshot.

Abstract: A system and method for detecting, identifying, and fixing the location of the source of an acoustic event. The inventive system includes: a plurality of sensors dispersed at somewhat regular intervals throughout a monitored area; a communication network adapted to deliver information from the sensors to a host processor; and a process within the host processor for determining, from the absolute times of arrival of an event at two or more sensors, a position of the source of the event. Acoustic events are detected and analyzed at each sensor so that the sensor transmits over the network: an identifier for the sensor; an identifier for the type of event; and a precise absolute time of arrival of the event at the sensor. In a preferred embodiment, the system also identifies the type of weapon firing a gunshot.

Abstract: An ultrasound position determination system includes a base unit and at least one mobile unit. Each of the mobile and base units are operable to transmit and receive ultrasonic signals. The mobile unit is adapted to transmit a predetermined signal in dependence upon the state of transmission of the base unit. The base unit is adapted to determine the time taken for the signal to pass from the mobile unit to the base unit and thereby calculate a distance between the mobile unit and the base unit.

Abstract: Exemplary systems and methods are directed to transmission of electromagnetic (EM) pulses in a downhole environment, which is located below a surface of a landform. A sequence of EM energy pulses is generated from a signal generator located at the surface of the landform. The energy pulses are reflected at a ring frequency by one or more downhole transducers. The reflected energy pulse is received at a receiver, which is located at the surface, during a predetermined time interval. The receiver detects the received energy pulses through a time domain or frequency domain technique. The detected ring frequency is correlated to a parameter or condition of the downhole environment.

Abstract: A system for locating an acoustic source from an acoustic event of the acoustic source. In one embodiment, the system includes a sensor network having a plurality of spatially separated sensor nodes each located in a predetermined position encountering acoustic waves generated by an acoustic event passing proximate to the plurality of spatially separated sensor nodes, where the plurality of spatially separated sensor nodes are synchronized to a common time base such that when the acoustic event is detected, information of the acoustic waves from each of the plurality of spatially separated sensor nodes is obtained and broadcasted through the sensor network. The system further includes a base station for receiving information of the acoustic waves broadcasted from the sensor network and processing the received information of the acoustic waves so as to locate the acoustic source of the acoustic event.

Abstract: A system captures motion data in natural environments. A set of sources and a set of sensors are arranged on an object such as a human body. Each source emits ultrasonic signals detected by the sensors. A driver module is also arranged on the body. The driver module generates the ultrasonic signals for the set of sources and timing signals for the set of sensors. Distances between the set of sources and the set of sensors are measured based on a time of flight of the ultrasonic signals. Three dimensional locations of the set of sources and the set of sensors are determined from the distances. The distance measurements are refined using inertial components that provide rotation rates and accelerations. All these measurements together yield poses or configurations of the object.

Abstract: A system and method for archiving and retrieving information from an array of remote sensors. In a preferred embodiment the invention is incorporated in a gunshot detection and location system to preserve audio information surrounding a gunshot event for later review or analysis. In a preferred embodiment the system includes a plurality of acoustic sensors deployed in an array, a computer for processing gunshot information from the sensors, and a mass storage device for temporary archival of audio information. When a gunshot event is detected, the location of the audio information of the data within the spool is stored in an index to facilitate later retrieval of the information.

Abstract: In a building environment, a distance associated with a building automation device is determined as a function of an inserted time delay between a wireless transmission of a signal and wireless reception of another signal. For example, a two-way communication is provided with a time delay inserted before responding to a received transmission. By using two-way transmissions, the building automation devices may be free of clock synchronization. Acoustic signals may be used in a building environment to determine a distance. The building automation device may also use radio frequency information for communicating with other devices. Communication between devices allows a controller to coordinate the determination of distances associated with different devices within a network, such as through transmission of a test signal and assigning distance measurement operations to devices that receive the test signal with sufficient strength or other characteristics.

Abstract: Systems and methods for determining and disambiguating the location of the shooter of supersonic projectiles based on shockwave-only signals are described. Using several spaced sensors, an initial portion of the shockwave-only signals is sensed to determine Time-Differences-Of-Arrival (TDOA) for the sensor pairs. The resulting TDOAs are used to determine the gradient of curvature of the shockwave wavefront on the sensors. The gradient of curvature is then used to determine the disambiguated projectile trajectory.

Abstract: Provided is a method for controlling a positioning system using ultrasonic waves. The method installs a plurality of ultrasonic satellites generating ultrasonic signals to position a mobile. The method sequentially gives satellite identification numbers to the plurality of ultrasonic satellites, generates a synchronization signal and providing it to the plurality of ultrasonic satellites, and allows the mobile to receive ultrasonic signals, which are generated by the plurality of ultrasonic satellites in the order of the satellite identification numbers when the ultrasonic satellites receive the synchronization signal, to measure distances between the mobile and the ultrasonic satellites.