Abstract: A system for determining the origin and trajectory of a gunshot includes spaced sensor nodes and a base station. A method for determining the origin and trajectory of a gunshot includes the steps of, at the nodes, sensing acoustic signals, converting the acoustic signals into digital signals, separating the digital signals into segments, calculating a time of arrival of each segment, and extracting features from each segment, and then at the base station identifying each time of arrival as a main shock wave or a main muzzle blast time of arrival from the features, and computing the trajectory from the main shock wave times of arrival. The computed trajectory includes velocity and acceleration. The method also includes computing, at the base station, the origin from the main muzzle blast times of arrival.

Abstract: The systems and methods described herein relate to an airborne shooter detection system having a plurality of sensors coupled to the body of an aircraft such as a helicopter. The sensors are arranged to receive shockwave-only signals. The received signals are analyzed to determine an unambiguous shooter location. The analysis may include measuring the arrival times of the shockwaves of projectiles at each of the sensors, determining the differences in the arrival times among sensors, computing a set of ambiguous solutions corresponding to a shooter, and clustering this set of solutions to determine the unambiguous shooter location. The systems and methods described herein may also be used to determine if multiple shooters are present, and subsequently determine the shooter locations for each of the multiple shooters.

Abstract: An acoustic wave detection device including a piezoelectric transducer configured to provide a detection signal; an acoustic resonator having a resonance frequency and including a resonating body having a free surface to be adhered against a substrate in which a seismic acoustic wave, having a frequency spectrum including the resonance frequency of the resonator, is propagated, the seismic acoustic wave causing the acoustic resonator to resonate by the free surface; and a microphone diaphragm having a frequency spectrum including the resonance frequency of the resonator. The diaphragm vibrates by an aerial acoustic wave that causes the acoustic resonator to resonate by the microphone diaphragm. The piezoelectric transducer is attached onto the acoustic resonator to produce a first component of detection signal, when the acoustic resonator resonates by the seismic acoustic wave, and produces a second component of detection signal when the acoustic resonator resonates by the aerial acoustic wave.

Abstract: An inline inspection system and method for calibrating an acoustic monitoring structure installed along a pipe. The system includes a pipe inspection vehicle; a microprocessor configured to attach a time stamp to a measured distance traveled by the pipe inspection vehicle; an acoustic source attached to the pipe inspection vehicle and configured to generate sound waves inside the pipe, the sound waves having predetermined frequencies and predetermined amplitudes; plural sensors disposed along the pipe and configured to record time of arrivals and intensities of the sound waves generated by the acoustic source; and a processing unit configured to communicate with the plural sensors and receive the time of arrivals, intensities and frequencies of the sound waves from the plural sensors. The processing unit calibrates the acoustic monitoring structure by calculating a distance between the acoustic source and a first sensor of the plural sensors.

Abstract: A method for detecting series of substantially periodic bursts of substantially sinusoidal signals, in particular, but not exclusively, series of bursts of signals transmitted recurrently (by pingers for example), this method making it possible to ensure the quick and reliable detection of such signals in the presence of significant interference noise. This method includes slightly delayed processing of received signals, spectral analysis and time integration, and presentation of the results in the form of a two-dimensional image of the successive recurrences of the bursts according to time slots of the received signals.

Abstract: A survey method giving improvements in weapons fire location systems is disclosed. In an urban system with a distributed array in the midst of many buildings that block signal paths or create echoes, methods are provided to measure signal propagation. A survey or tour of the covered region uses a moving signal source to probe propagation inside the region. Survey results may indicate where more or fewer sensors are needed. Survey results plus current measured noise gives prediction of instantaneous system sensitivity. In addition, multipath propagation may be used to determine a location even when only one or two sensors detect the signal. In such exemplary cases, triangulation may be replaced or augmented by pattern recognition. Further, signals of the survey need not be acoustic impulses such as gunfire, but may be RF signals, or coded continuous signals so that gunfire-like sounds would not disturb citizens in the area.

Abstract: A system for three-dimensional tracking of high speed undersea projectiles may utilize a distributed field of randomly positioned passive acoustic sensors. The system measures variables related to the pressure field generated by a supercavitating projectile in flight wherein the amplitude of the pressure generated at a point in space is related to the projectile dimensions, velocity, and trajectory. The system iteratively processes data from the sensors to measure launch velocity, flight direction (trajectory), ballistic coefficient (drag), and/or maximum range.

Abstract: An aspect of the present invention is drawn to method of determining a location of a submersible vehicle. The method includes obtaining first bearing information based on a location of a ship at a first time relative to the submersible vehicle and receiving broadcast information from the ship, wherein the broadcast information includes location information related to a second location of the ship at a second time, a velocity of the ship at the second time and a course of the ship at the second time. The method further includes obtaining second bearing information based on the second location of the ship at the second time relative to the submersible vehicle, obtaining a velocity of the submersible vehicle at the second time and obtaining a course of the submersible vehicle at the second time.

Abstract: The invention relates to an automated estimation of the position (co-ordinates) of a set of loudspeakers in a ioom Based on measured impulse responses the distances between each pair of loudspeakers are estimated, thereby forming a distance matrix, and the resultant distance matrix is used by a multidimensional scaling (MDS) algorithm to estimate the co-ordinates of each individual loudspeaker An improved co-ordinate estimation can, if desired, be derived by utilizing the stress values provided by the MDS algorithm.

Abstract: A system and method for continuous detection of impacts on pipelines for fluid transportation, particularly on pipelines placed on the seabed. The system includes at least two sensors each installed in correspondence with an end of a section subject to detection of a pipeline. A first sensor of the at least two sensors is configured to detect first acoustic waves, which propagate along a first transmission phase associated with the pipeline, and a second sensor of the at least two sensors is configured to detect second acoustic waves which propagate along a second transmission phase associated with the pipeline. The second acoustic waves have different elastic features with respect to the first acoustic waves.

Abstract: Methods and apparatus determining a position of a submersible vehicle within a body of water are provided. A method comprises determining an initial position of the vehicle while the vehicle is at or near a water surface. The method further comprises coupling the vehicle and a base node to a weight and determining a position of the base node once the base node and vehicle have reached the floor of the body of water using acoustic modems of the vehicle and a surface vessel to aid in calculating the position as they descend, and acoustically transferring the at rest position on the seafloor from the vehicle to the node. The method further comprises decoupling the vehicle from the node and weight and determining a position of the vehicle based on the position of the base node and acoustic signals exchanged between acoustic modems of the vehicle and the base node.

Abstract: A sound source localization system includes a plurality of microphones for receiving a signal as an input from a sound source; a time-difference extraction unit for decomposing the signal inputted through the plurality of microphones into time, frequency and amplitude using a sparse coding and then extracting a sparse interaural time difference (SITD) inputted through the plurality of microphones for each frequency; and a sound source localization unit for localizing the sound source using the SITDs. A sound source localization method includes receiving a signal as an input from a sound source; decomposing the signal into time, frequency and amplitude using a sparse coding; extracting an SITD for each frequency; and localizing the sound source using the SITDs.

Abstract: Systems and methods for processing signals received from at least two sources are described. The two sources may each include an array of sensors. The sensor arrays may be spaced apart on the surface of a body, such as an aircraft, a ground vehicle, or a building. The sensors are configured for receiving signals from the at least two sources indicative of timing information. The timing information may be associated with a shockwave of a projectile and a location processor configured for determining shooter location based on signals output by each of the at least two arrays of sensors is coupled to each of the at least two arrays of sensors. The location processor is configured to compute global time metrics and local reference times associated with each of the sensors and determine shooter location based on a relationship between computed global time metrics and local reference times.

Abstract: A method of signal processing includes calculating a range based on information from a reflected ultrasonic signal. Based on the calculated range, one among a plurality of direction-of-arrival (DOA) estimation operations is selected. The method also includes performing the selected operation to calculate an estimated direction of arrival (DOA) of an audio-frequency component of a multichannel signal. Examples of DOA estimation operations include operations based on phase differences between channels of the multichannel signal and operations based on a difference in gain between signals that are based on channels of the multichannel signal.

Abstract: A portable measurement system is provided including a probe, a user interface control and a receiver. The probe includes a plurality of ultrasonic transducers that emit ultrasonic waveforms for creating a three-dimensional sensing space. The user interface control captures a location and position of the probe in the three-dimensional sensing space. The receiver includes a plurality of microphones to capture the ultrasonic waveforms transmitted from the probe to produce captured ultrasonic waveforms and a digital signal processor that digitally samples the captured ultrasonic waveforms and tracks a relative location and movement of the probe with respect to the receiver in the three-dimensional ultrasonic sensing space from time of flight waveform analysis. Embodiments are demonstrated with respect to hip replacement surgery, but other embodiments are contemplated.

Abstract: Systems and methods are disclosed for locating a weapon fire incident such as an acoustic transient from a gunshot, explosion, weapons launch, etc. In one exemplary implementation, there is provided a method of locating the incident from a combination of propagation phenomena including a discharge time of the weapon fire incident. Moreover, the method may include obtaining a first propagation parameter of the incident from one or more first sensors, obtaining the discharge time from another sensor, and processing the data to determine a location using a common time basis among sensor measurements. According to further exemplary implementations, the discharge time may include a transient event that has a different propagation velocity than that of sound in the atmosphere.

Abstract: A man wearable acoustic sensor for use with a gunshot detection system. In a preferred embodiment the inventive sensor includes: a housing configured to be man wearable, a microphone; a processor housed within the housing and in communication with the microphone to detect an acoustic event and determine a time of arrival for the acoustic event; a GPS receiver for providing position information to said processor; a network; and a display for displaying information concerning acoustic events to a user. Man wearable describes a sensor which is either integrated into a piece of equipment normally carried by a soldier or integrated into an article of clothing or configured to securely attach to such equipment or clothing.

Abstract: Disclosed is a moving object and a location measuring device and method thereof that may transmit an ultrasound signal to the moving object through a plurality of ultrasound transmitting units, and may estimate a location of the moving object at a current time based on distance information of distances between the moving object and the plurality of ultrasound transmitting units measured based on the transmitted ultrasound, inertia information, and location information of the moving object at a time prior to the current time.

Abstract: A method and apparatus is provided for acoustic ranging by application of linear period modulated sound. In one aspect of the instant invention, an apparatus is provided for acoustic ranging by application of linear period modulated sound. The apparatus includes at least one source adapted to generate at least one modulated Doppler invariant signal and at least one receiver deployed along a seismic sensing cable, wherein the receiver is adapted to receive at least one modulated Doppler invariant signal from the at least one source. The apparatus further includes a signal processing unit adapted to determine the propagation time delay between the source and the receiver using the modulated Doppler invariant signal and the received Doppler invariant signal.

Abstract: A method, apparatus and software is disclosed in which the location of the origin of a received acoustic emission in a structure is calculated by triangulating the times of flight of the acoustic emission to a distributed set of sensors and using a predetermined acoustic model of the structure.

Abstract: An autonomous ultrasonic indoor location system includes a location beacon transmitting apparatus and a location beacon receiving apparatus. The location beacon transmitting apparatus is configured to sequentially transmit US signals at a predetermined time interval upon transmission of a signal containing synchronization information.

Abstract: A method for measuring sea waves includes: transmitting ultrasonic waves from an ultrasonic transmitter 2 provided on a buoy 1 into the sea, and receiving the ultrasonic waves from three transponders 3 on the seabed together with the time signals; detecting distances between the transponders 3 and the ultrasonic transmitter 2 based on the propagation time of the ultrasonic waves; high-pass filtering the distance data to extract a short-term fluctuation component; preparing and solving linear equations to determine the displacement in the height direction of the short-term fluctuation component and obtain a wave height.

Abstract: An apparatus and method of sniper localization includes an internal clock; an acoustic sensor positioned in a known location and detecting pressure waves; a first processor determining the trajectory of the supersonic projectile, where the first processor includes a shock wave threshold detector receiving time series information and recording arrival times of shock wave components of the pressure waves; a blast threshold detector receiving the time series information and recording arrival times and amplitude information of blast wave components of the pressure waves; a discrimination processor discriminating between a blast wave, a shock wave, or neither, and storing arrival times of each of the potential blast wave components classified as the blast wave; and a localization estimation processor calculating an estimated trajectory of the projectile based on the blast wave and the shock wave arrival times and calculating an estimated firing position of the projectile.

Abstract: There is provided a method and associated apparatus for measurement. Specifically, a method for determining a distance travelled by a signal in a medium, or the time of flight of a signal travelled. The method comprises considering an unambiguous range wherein the unambiguous range greater than a distance to be travelled by a signal. A signal is then transmitted across the distance to be determined, the signal comprising at least two frequency components, the frequency components based on the unambiguous range and the speed of the signal in the medium. The distance travelled (or the time of flight) is determined by using the variance of the received phase characteristics, such as phase angle) of one frequency component of the received signal with the received phase characteristics of another frequency component of the received signal.

Abstract: An apparatus includes sound sensors for converting sounds into electric signals. An angular position of a sound source of a first sound wave as seen from the apparatus is determined on the basis of moments of arrival of the first sound wave at the respective sound sensors which are represented by the electric signals. An angular position of a sound source of a second sound wave as seen from the apparatus is determined on the basis of moments of arrival of the second sound wave at the respective sound sensors which are represented by the electric signals. Calculation is given of a relative angle between the determined angular position of the sound source of the first sound wave and the determined angular position of the sound source of the second sound wave. A condition of the apparatus is controlled in response to the calculated relative angle.

Abstract: Various embodiments of the present invention are directed to systems and methods for multimodal object localization using one or more depth sensors and two or more microphones. In one aspect, a method comprises capturing three-dimensional images of a region of space wherein the object is located. The images comprise three-dimensional depth sensor observations. The method collects ambient audio generated by the object, providing acoustic observation regarding the ambient audio time difference of arrival at the audio sensors. The method determines a coordinate location of the object corresponding to the maximum of a joint probability distribution characterizing the probability of the acoustic observations emanating from each coordinate location in the region of space and the probability of each coordinate location in the region of space given depth sensor observations.

Abstract: A method and apparatus for identifying running vehicles in an area to be monitored using acoustic signature recognition. The apparatus includes an input sensor for capturing an acoustic waveform produced by a vehicle source, and a processing system. The waveform is digitized and divided into frames. Each frame is filtered into a plurality of gammatone filtered signals. At least one spectral feature vector is computed for each frame. The vectors are integrated across a plurality of frames to create a spectro-temporal representation of the vehicle waveform. In a training mode, values from the spectro-temporal representation are used as inputs to a Nonlinear Hebbian learning function to extract acoustic signatures and synaptic weights. In an active mode, the synaptic weights and acoustic signatures are used as patterns in a supervised associative network to identify whether a vehicle is present in the area to be monitored. In response to a vehicle being present, the class of vehicle is identified.

Abstract: The present disclosure relates to a method and system for finding and physically altering underground targets. Multiple projectiles are dispersed into the ground and determine their spatial orientation using seismic waves, and then operate as an array to locate and properly time kinetic pulses to focus seismic waves on the target.

Abstract: Methods and systems for determining a geophysical position of an object in an underwater channel are provided. Acoustic signals from at least two sources are received by a receiver of the object. The acoustic signals have a frequency corresponding to at least one waveguide mode associated with the underwater channel, where the acoustic signals are transmitted at predetermined transmission times. An arrival time for the at least one waveguide mode is determined from the received signals, based on the predetermined transmission times. The geophysical position is determined based on the arrival time and a modal group velocity for the at least one waveguide mode.

Abstract: Systems and methods for obtaining target elevation information are disclosed. The systems and methods use multiple vertical transmitters and one or more receivers to infer changes in the elevation plane and the height of objects. Changes in elevation and heights of objects are inferred from path length differences between the transmitters and a particular backscattering point. Using known geometric information regarding the configuration of the transmitters, propagation time differences can be estimated via time delay estimation methods in either the time or frequency domain. Appropriate modulation schemes are used such that the multiple signals transmitted are separable upon reception.

Abstract: An apparatus and method for localizing a sound source in a robot are provided. The apparatus includes a microphone unit implemented by one or more microphones, which picks up a sound from a three-dimensional space. The apparatus also includes a sound source localizer for determining a position of the sound source in accordance with Time-Difference of Arrivals (TDOAs) and a highest power of the sound picked up by the microphone unit. Thus, the robot can rapidly and accurately localize the sound source in the three-dimensional space with minimum dead space, using a minimum number of microphones.

Abstract: Audio system and related method integrated with ultrasound communication functionality are provided. A communication transmitting device of proposed invention modulates a communication signal of communication functionality to a high-frequency sound and transmits the high-frequency sound by an ordinary audio transmitter. A communication receiving device of proposed invention receives the high-frequency sound with an ordinary audio receiver and demodulates it to retrieve the communication signal, and then the communication device can use the communication signal. The proposed audio sound transmitter/receiver can be implemented using low-cost audio speaker/microphone, such that a cost for implementing communication functionality can be reduced.

Abstract: The present disclosure relates to a method and system for finding and physically altering underground targets. Multiple projectiles are dispersed into the ground and determine their spatial orientation using seismic waves, and then operate as an array to locate and properly time kinetic pulses to focus seismic waves on the target.

Abstract: Disclosed are systems and methods that can be used to detect shooters. The systems and methods described herein use arrival times of a shockwave, produced by a shot, at a plurality of sensors to assign weights to each of the plurality of sensors, and determine a shot trajectory based on the assigned weights.

Abstract: Disclosed are systems and methods that can be used to detect shooters. The systems and methods described herein use arrival times of a shockwave, produced by a shot, at a plurality of sensors to assign weights to each of the plurality of sensors, and determine a shot trajectory based on the assigned weights.

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 event detection and localization system is provided that employs a plurality of smartphones. The detected events may comprise a gunshot, a biological threat, a chemical threat and/or a radiological threat. Each smartphone comprises a memory for storing an event detection process; and at least one hardware device to implement the event detection process. The hardware device is operative to detect an event based on a signal obtained using a sensor in the vicinity of the smartphone; obtain a time of arrival of the signal; obtain a location of the smartphone at the time of arrival; send a notification of the arrival time and arrival location to one or more of another smartphone and a server; and receive an indication of an origination of the event.

Abstract: Disclosed are an apparatus and a method of location tracking. The location tracking apparatus may calculate a location of an object using an ultrasound. In this instance, an intensity of the used ultrasound may be determined based on a distance to the object, thereby reducing unnecessary power consumption.

Abstract: Systems and methods are disclosed for processing weapon fire information such as gunfire. In one exemplary implementation, there is provided a method of processing gunshot information to determine source location information involving echo/reflection processing features. Moreover, the method may include processing gunshot information received from a source at a sensor having a reflecting surface at a given distance, processing direct arrival time and echo arrival time information, and determining source location information as a function of a virtual sensor calculated behind the surface.

Abstract: The position of a mobile unit (12) within a detection zone is determined. An acoustic signal is emitted from the mobile unit and received along a first path (54). An echo of the signal is received after reflection from a surface (46) within said detection zone. The position of the mobile unit (12) within the detection zone is determined from the times of arrival of the signal and echo.

Abstract: A pen transcription system and method for using the same are disclosed. The pen transcription system includes a receiver having first and second acoustical sensors mounted on a planar base and separated from one another, an EM detector, and a controller. The first and second acoustical sensors detect an acoustical signal emitted by a moveable signal source. The EM detector detects an EM signal that is synchronized with the acoustical signal. The controller measures the difference in time of detection between the EM signal and the acoustical signals detected by the first and second acoustical sensors. The acoustical sensors include a detector and a housing surrounding the detector, the housing having an aperture defined by an axis. The acoustical sensor has a reception function that is symmetrical about the axis and the axis is substantially perpendicular to the base surface.

Abstract: A method and apparatus for determining the direction of a sound source is disclosed. The method includes determining time differences of arrival of the sound at N locations and using the differences to determine the angular direction of the source. The apparatus indicates the angle of arrival and additionally indicates the type of the sound source.

Abstract: In accordance with some embodiments of the present disclosure, a process for determining a direction vector of a sound source is described. The process may be implemented to detect, by a first sound sensor, a first sound pressure of a sound wave propagated from the sound source, and detect, by a second sound sensor, a second sound pressure of the sound wave. The process may further be implemented to determine, by a processor, the direction vector of the sound source relative to the first sound sensor and second sound sensor, wherein the direction vector is based on the first sound pressure, the second sound pressure, and a first distance between a first physical location of the first sound sensor and a second physical location of the second sound sensor.

Abstract: The present invention relates to a method for determining an acoustic property of an environment. According to the method a sound signal and at least two reflection signals of the sound signal (are received, and for each of the reflection signals a time difference between a time of reception of the sound signal and a time of reception of the respective reflection signal is determined. Furthermore, for each of the reflection signals, an angle between a reception direction in which the sound signal was received and a reception direction in which the respective reflection signal was received is determined. Based on the determined time differences, the angles and predetermined constraints defining arrangement constraints of the sound reflecting surfaces an arrangement of the sound-reflecting surfaces is determined.

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: A pen transcription system and method for using the same are disclosed. The pen transcription system includes a receiver having first and second acoustical sensors mounted on a planar base and separated from one another, an EM detector, and a controller. The first and second acoustical sensors detect an acoustical signal at a first wavelength emitted by a moveable signal source. The EM detector detects an EM signal that is synchronized with the acoustical signal. The controller measures the difference in time of detection between the EM signal and the acoustical signals detected by the first and second acoustical sensors. The acoustical sensors include a detector and a housing surrounding the detector, the housing having an aperture having a maximum dimension that is less than the first wavelength divided by 6.28.

Abstract: Method and apparatus for locating an object (2) that is to be located relative to a reference object (1), by electrically generating a locating signal (SL) by modulating a carrier signal with pseudo-noise. The modulation is continuous and of the ultra-wideband (UWB) type. Analysis using a cross-correlation function between said locating signal (SL) and received reflected signals (SRR1, SRR2) serves to segregate waves that have followed a direct path and any interfering waves that have followed indirect paths, so as to be able to deduce therefrom the shortest overall propagation time corresponding to those of said locating waves (OL) that have followed direct paths. The invention applies in particular to a rotary wing aircraft, e.g. a helicopter drone.

Abstract: The invention relates to a method for determining the location of an impact on a surface of an object based on the analysis of an acoustic signal generated by the impact. This method further comprises a signal treatment step of weighting the acoustic signal to take into account spurious contributions in particular due to reflections at the border of the object.

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 level measurement system suitable for use in a high temperature and pressure environment to measure the level of coolant fluid within the environment, the system including a volume of coolant fluid located in a coolant region of the high temperature and pressure environment and having a level therein; an ultrasonic waveguide blade that is positioned within the desired coolant region of the high temperature and pressure environment; a magnetostrictive electrical assembly located within the high temperature and pressure environment and configured to operate in the environment and cooperate with the waveguide blade to launch and receive ultrasonic waves; and an external signal processing system located outside of the high temperature and pressure environment and configured for communicating with the electrical assembly located within the high temperature and pressure environment.