Abstract: A system for locating and identifying an acoustic event such as gunfire. The inventive system employs a plurality of man wearable acoustic sensors for detecting gunfire, each acoustic sensor having a display associated therewith for displaying information concerning the acoustic event to a user. In preferred embodiments, the sensor includes a microphone for receiving acoustic information; an A/D converter; a processor for processing the digitized signal to detect a gunshot and determine a time of arrival; a GPS receiver for determining the position of the acoustic sensor; and a network interface for bidirectional communication with a system server. Preferably the display comprises: an LCD; and an electronically readable compass. When the display and acoustic sensor are in separate housings, the acoustic sensor includes a transmitter and the display includes a receiver for transferring the gunshot information.

Abstract: An apparatus for processing passive acoustic signals received on a horizontal line array that were either emitted from an underwater object or echo returned from an object, is proposed to track the motion (bearing change and range change) of an object (target) relative to the receiver horizontal line array. Adaptive array processing for a moving object is biased for a moving source when the number of data samples is limited by the stationariness condition. Motion compensation can be carried out in the beam domain by beam shifting for a bearing changing object and frequency shifting for a range changing object. The method includes receiving acoustic signals from the target, determining the beam covariance matrices, determining the target bearing rate and range rate, processing the beam covariance matrices by compensating for the target motion, and producing a beam power plot versus time.

Abstract: A method and apparatus for the determination of a stationary and/or moving object, such as a vehicle, acoustic signals emitted by the object and/or reflected by another object are recorded and used to evaluate or identify an object. The object is detected, evaluated and identified acoustically with the aid of noises from it and/or extraneous noises, with respect to its own movement profile in relation to one or more coordinate axes (x, y axes), in the manner of a self-localization based on sound waves.

Abstract: Described is a system and method for detection using an ultrasonic wave. The system may include a first arrangement and a second arrangement. The first arrangement may include a transmitter and a receiver. The transmitter transmits an ultrasonic wave along a surface on which items are to be stored and the receiver receives the wave after it has passed over the surface. The second arrangement receives from the first arrangement data corresponding to properties of the received wave. The second arrangement compares the properties of the received wave to properties of the transmitted wave to generate current condition value. The second arrangement determines based on the current condition value and calibration data a current condition state corresponding to a degree of the surface currently occupied by the items. The calibration data includes at least one calibration value and a corresponding calibration condition state.

Abstract: There are provided a speaker distance detection apparatus and method using a microphone array, capable of exactly detecting the distance between a speaker and even a small terminal such as a mobile telephone, and a speech input/output apparatus using the method. The speaker distance detection apparatus uses a microphone array composed of a plurality of microphones, previously determines a reference microphone to be a reference among a plurality of microphones, detects differences between a signal level of the reference microphone and signal levels of the other microphones, based on correlations between signals in the respective microphones, and determines the distance from the microphone array to the speaker based on the detected signal level difference.

Abstract: A position detecting device for detecting the position of an object (12) movable along a predetermined path of movement, comprising a signal transmission medium (13) extending along the path of movement, a signal generator (15) movable together with said movable object (12), by means of which a signal can be coupled into the signal transmission medium (13), at least one signal receiver (29, 33) at an extraction location in an end portion of said path of movement, a signal propagation time measuring means (35, 37) adapted to determine the signal propagation time between coupling location and extraction location (45), wherein the signal generator (15) is designed to deliver a periodically repeating signal pulse sequence (FIG.

Abstract: An acoustic event location and classification system comprising an array of at least two acoustic transducers arranged spaced from one another; a central data processing unit for receiving signals from the acoustic transducers and processing the signals to determine a event type and location; and an internet or LAN connection for transmitting event type and location data to a third party, wherein the central data processing unit uses a DSNN to determine the event type and generalized cross correlation functions between microphone pairs to determine the event location.

Abstract: The invention relates to a device that is used to analyse the structure of a material. The inventive device comprises: probe elements (5) which are used to (i) emit a wave, in the material, with emission delay laws that correspond to several simultaneous deviations and (ii) receive, on the different probe elements (5), signals from the refraction of said wave by the material; detection channels, each detection channel being connected to a probe element (5), in order to collect the refraction signals and to transmit same to data processing means (4); and delay circuits that apply a delay on each detection channel according to the reception delay laws which are predetermined and which correspond to the different deviations of the wave emitted. The invention also relates to an analysis method which can be used, in particular, on said device.

Abstract: An object localising system comprises sensor devices at different sites, each sensor device being capable of detecting a signal from an object, and control means for repeatedly responding to the outputs of the sensor devices by selecting a sub-set of the devices and determining the amount by which the times at which the devices of the sub-set receive the signal are delayed with respect to each other to enable calculation of the current location of the object. Each sensor device can be switched between a master mode, in which the device is operable to transmit events derived from a signal from an object, and a slave mode, in which the device is responsive to such events from another sensor device for processing its own signal in order to determine the time delay between receipt of the signals by the sensors of the respective devices.

Abstract: A system and method for protecting sensor positions in an array of acoustic sensors which make up a gunfire locator system. The inventive system includes a purity of sensors and a host computer. Each sensor includes: a microphone for receiving acoustic information; a processor for processing acoustic information to detect an acoustic event and determine a time of arrival; a GPS receiver; an encryption module for encrypting transmitted sensor positions; and a network interface for transmitting sensor positions and times of arrival. The host computer includes: a network interface for receiving sensor transmissions; an encryption module for deciphering sensor positions; and a CPU.

Abstract: A double feed detecting apparatus provided with an ultrasonic transmitter installed on one side of a transport path for a sheet material for transmitting an ultrasonic toward the sheet material, an ultrasonic receiver installed on the other side of the transport path for the sheet material for receiving the ultrasonic transmitted by the ultrasonic transmitter and outputting a received ultrasonic signal, a first determining device for determining whether double feed or not in accordance with the amplitude of the received ultrasonic signal output by the ultrasonic receiver, and a second determining device for detecting a phase change in the received ultrasonic signal, and determining whether double feed or not on the basis of the detected phase change.

Abstract: The present application discloses a method for resolving harmonic ambiguity and inter-array harmonic tracking. The method allows derivation of a complete set of possible harmonic families given the selection (by an operator) or automatic detection (by an automated algorithm) of a single tone (fselected) from a frequency spectrum using a novel “ambiguity matrix” approach in which a matrix of all N possible harmonic members and M hypothetical fundamentals is constructed. The ambiguity matrix provides an image of all possible harmonic families associated with a selected tone. The selection of the correct fundamental is then made based on simple comparisons between this image and the set of all possible fundamentals. The ambiguity matrix effectively provides a reduced finite solution space (discrete set of possibilities) in which to unambiguously estimate the correct fundamental.

Abstract: Systems and methods for locating the shooter of supersonic projectiles based on shockwave-only measurements are described. Muzzle blast signals are neither sought nor required. The system uses at least five, preferably seven, acoustic sensors that are spaced apart at least 1 meter. The sensor signals are acquired with a time resolution in the order of microseconds and processed to find and disambiguate the shockwave arrival angle unit vector. Two different Time-Difference-Of-Arrival (TDOA) measurement techniques are described, with one technique using counters in each signal channel and the other technique using cross-correlation between signal channels. A genetic algorithm can be used to efficiently disambiguate the results.

Abstract: A time measurement system for measuring the delay between first and second signals comprises means for detecting the times of upcrossings when the first signal crosses a predetermined level (preferably substantially different from the average level) with a positive slope and the times of downcrossings when the first signal crosses the predetermined level with a negative slope. These events are transmitted to a remote device receiving the second signal, which uses the events to define respective staggered segments of the second signal, to sum said segments and to detect a predetermined feature in said sum, the position of said feature representing the delay between the first and second signals.

Abstract: The relative position and orientation between two subsea structures (210, 212) are measured by ultra-short baseline acoustic metrology. Dual mode master/slave (220, 222) stations comprising a multi-transducer array are fitted in known position and orientation relative to each structure. The first station (220) is operated in master mode to determine the position and direction of the second structure (222) relative to the first (220). The second station (222) is operated in master mode to determine the position and direction data from both operations the apparatus calculates relative position and orientation between the structures. The dual mode stations can be replaced by a master station and a slave station, swapping places.

Abstract: Method and apparatus for locating and quantifying sound sources using an array of acoustic vector probes (200). Signals received at the probes are converted to digital form and fed into a digital signal processor (400) which computes the sound pressure and the sound-intensity vector at each probe. The set of sound-intensity vectors measured by the array provides a set of directions to a sound source (100) whose approximate spatial coordinates are determined using a least-squares triangulation formula. The sound-intensity vectors also determine sound-power flow from the source. In addition sound pressure measured by the probes can be phased to form a sensitivity beam (250) for scanning a source. Sound-intensity measurements made concurrently can be used to determine the spatial coordinates of the part being scanned and the sound power radiated by that part. Results are displayed on a computer screen or other device (500) permitting an operator to interact with and control the apparatus.

Abstract: An underwater target tracking capability is disclosed for a grid-search technique utilizing parameter evaluation plot techniques comprising processing acoustic sonar measurements in conjunction with additional kinematics and environmental information. In the implementation described here, the measurements considered are passive broadband sphere bearings together with limiting knowledge of target speed and range at initial detection. These information sources are processed in a manner especially suited to enable rapid response to the emerging tactical situation.

Abstract: A system and related method for the detection of low power broadband signal sources in a high noise environment. The system uses multiple collinear arrays of sensors to receive data signals. The sensor-to-sensor spacing within the arrays is greater than one-half the wavelength of the center frequency associated with the broadband spectrum of interest. The signals are processed using nonlinear spectral estimation to remove periodic signals from the data signals to obtain broadband data. A cross correlation matrix is formed from the broadband data. Nonlinear spectral estimation is applied to the cross correlation matrix to determine the angular direction of the low power broadband signal sources with respect to the arrays.

Abstract: A desired acoustic signal is extracted from a noisy environment by generating a signal representative of the desired signal with a processor. The processor receives aural signals from two sensors each at a different location. The two inputs to the processor are converted from analog to digital format and then submitted to a discrete Fourier transform process to generate discrete spectral signal representations. The spectral signals are delayed by a number of time intervals in a dual delay line to provide a number of intermediate signals, each corresponding to a different spatial location relative to the two sensors. Locations of the noise source and the desired source are determined and the spectral content of the desired signal is determined from the intermediate signal corresponding to the noise source locations. Inverse transformation of the selected intermediate signal followed by digital to analog conversion provides an output signal representative of the desired signal.

Abstract: An apparatus for a bearing tracker is disclosed that provides improved estimates of target's bearing, bearing rate and signal-to-noise (SNR). The estimates are computed using normalized beam spectral data from short time interval preceding the initialization process.

Abstract: A method for determining position and velocity of targets from signals scattered by the targets using a first and a second station each including a transmitter/receiver of electromagnetic or acoustic signals. First, mono-static measurements are carried out from each station, and also a bi-static measurement between the stations. The two mono-static measurements are used to calculate a number of target candidates with 2-dimensional position and 2-dimensional velocity. These target candidates are tested against the result of the bi-static measurement and the target candidates which are found in all measurements with suitable error margins are retained.

Abstract: In order to locate electromagnetic or acoustic signal sources of a sensor configuration (1a through 1c) fitted with at least two electric outputs; where the incidence-dependent transfer functions between the acoustic signals incident on the input(s) of the sensor configuration (1a through 1c) and the electric output signals are different, the ratio (7x through 7xx) of the output signal is formed and the result then is correlated with the previously determined ratio function (11).

Abstract: The methods and systems relate to tracking targets, and more particularly to tracking multiple targets within a field of densely distributed sensor nodes using wave processing/analysis methods applied to “target-waves” in an observable physical phenomena. The “target-waves” are target induced perturbations of a physical phenomena that are analogous to a propagating wave where the wave propagation velocities are equal to the target velocities. The term “target” refers to an individual object, or a group of objects that can be treated as an entity, whose position, speed, direction, separation, etc. is of interest to a user. Some examples, not exclusive, are military vehicles (e.g. tanks) along a road, people on sidewalks or in halls, and ships at sea.

Abstract: A thermal sensor system is provided in combination with a maneuverable vehicle, particularly in an underwater application. The system includes a transport pipe having an intake and output for the passage of seawater. A thermal sensor is connected to the transport pipe for detecting an actual temperature of seawater within the transport pipe. Sensor electronics are provided in connection with the thermal sensor, the sensor electronics conditioning signals output by the thermal sensor. The selective sampling by the thermal sensor may either be intermittent or continuous according to system needs. Further, a control device is connected to the sensor electronics, acoustic equipment and a depth sensor in connection with the maneuverable vehicle allowing change of the vehicle's course in response to these inputs.

Abstract: The invention concerns panoramic audio devices to process the impulsive signals received by passive sonars. It consists in isolating, in each beam, impulsive signals in the frequency and time domains and then filtering them according to the characteristics of the human ear. All left and right signals are then summed in order to be listened to in a headset. It allows rapid processing of impulsive signals.

Abstract: Voice control systems are used in diverse technical fields. In this case, the spoken words are detected by one or more microphones and then fed to a speech recognition system. In order to enable voice control even from a relatively great distance, the voice signal must be separated from interfering background signals. This can be effected by spatial separation using microphone arrays comprising two or more microphones. In this case, it is advantageous for the individual microphones of the microphone array to be distributed spatially over the greatest possible distance. In an individual consumer electronics appliance, however, the distances between the individual microphones are limited on account of the dimensions of the appliance.

Abstract: A technique for suppressing interference with unknown phase shifts received by an array of sensor elements partitions the array into a plurality of subarrays. Each subarray is processed independently to suppress the interference. Next, the resulting data from each subarray are summed together. This summed data, which effectively represents data provided by the full array with interference suppressed, may be utilized to detect and/or localize a target of interest. Each subarray is processed independently of all other subarrays. No cross-subarray processing is required. This technique is applicable to linear arrays, multi-line arrays, planar arrays, cylindrical arrays, conformal arrays, and spherical arrays. Applicable sensors include acoustic sensors (e.g., sonar, ultrasonic), electromagnetic sensors (e.g. radar), and optical sensors (e.g., infrared, ultraviolet, visible light).

Abstract: A system and method for processing sonar information from an underwater hydrophone array, at frequencies having wavelengths less than two times a spacing between adjacent hydrophones. The method and system all for processing received underwater waveforms at high frequency limits beyond the mechanical limits of the array.

Abstract: An apparatus for ultrasonically detecting an edge of a web, includes a ultrasonic-wave transmitter transmitting ultrasonic-wave pulse train, a ultrasonic-wave receiver receiving the ultrasonic-wave pulse train and converting the received ultrasonic-wave pulse train into electric signals, the web being fed between the ultrasonic-wave transmitter and receiver, a rectifying circuit for rectifying the electric signals, a low-pass filter circuit for smoothing output signals transmitted from the rectifying circuit, a first sample-holding circuit for sampling an output signal transmitted from the low-pass filter circuit, at first timing, a second sample-holding circuit for sampling an output signal transmitted from the low-pass filter circuit, at second timing later than the first timing, a third sample-holding circuit for sampling an output signal transmitted from the first sample-holding circuit, at the second timing, and a differentially amplifying circuit for calculating a difference between output signals trans

Abstract: An object localising system comprises sensor devices at different sites, each sensor device being capable of detecting a signal from an object, and control means for repeatedly responding to the outputs of the sensor devices by selecting a sub-set of the devices and determining the amount by which the times at which the devices of the sub-set receive the signal are delayed with respect to each other to enable calculation of the current location of the object. Each sensor device can be switched between a master mode, in which the device is operable to transmit events derived from a signal from an object, and a slave mode, in which the device is responsive to such events from another sensor device for processing its own signal in order to determine the time delay between receipt of the signals by the sensors of the respective devices.

Abstract: A time measurement system for measuring the delay between first and second signals comprises means for detecting the times of upcrossings when the first signal crosses a predetermined level (preferably substantially different from the average level) with a positive slope and the times of downcrossings when the first signal crosses the predetermined level with a negative slope. These events are transmitted to a remote device receiving the second signal, which uses the events to define respective staggered segments of the second signal, to sum said segments and to detect a predetermined feature in said sum, the position of said feature representing the delay between the first and second signals.

Abstract: Enables the estimation of a sound source position at an angle in a system with a small number of microphones, which was conventionally difficult to perform, and improve the precision of estimating the sound source position. By forming a reflecting surface RS as an enveloping surface of a spheroid in which a position of sound collecting means and a sound source position are the focal points, a major reflected wave having a delay amount corresponding to a sound source position is generated, and the delay amount between the direct wave and the reflected wave is checked, whereby the sound source position is acquired and estimated.

Abstract: A system for the accurate determination of the position of an underwater vehicle comprising a system observer subsystem having a state velocity update module, a terrain matching module, means for generating a prediction of the terrain matching module's performance and a constrained extended Kalman filter subsystem. The constrained extended Kalman filter subsystem includes a steady state extended Kalman filter, a non-linear constraint module, and a state predictor.

Abstract: The position and orientation of a mobile unit is determined from ultrasonic waves received from beacons of known location. Orientation is determined from a phase difference of the sensed ultrasonic wave at plural receivers on the mobile unit. Signals from multiple beacons may be processed to solve for x, y and z position and for speed of sound. The receivers are spaced at greater than a half wavelength of the ultrasonic wave and signals from plural receivers are processed to remove multiple wavelength phase ambiguity. Two non-collinear sets of collinear receivers allow ambiguity resulting from symmetry of the receivers to be broken.

Abstract: There are provided a speaker distance detection apparatus and method using a microphone array, capable of exactly detecting the distance between a speaker and even a small terminal such as a mobile telephone, and a speech input/output apparatus using the method. The speaker distance detection apparatus uses a microphone array composed of a plurality of microphones, previously determines a reference microphone to be a reference among a plurality of microphones, detects differences between a signal level of the reference microphone and signal levels of the other microphones, based on correlations between signals in the respective microphones, and determines the distance from the microphone array to the speaker based on the detected signal level difference.

Abstract: A system and method for determining target solutions based on energy received at one or more sensors includes the step of displaying the received energy on a display. Target solution traces are overlaid onto the received energy trace. The operator selects tie-down points, and adjusts at least one of time, range, and bearing definitions for the tie-down points while observing the overlain traces, so as to obtain coincidence of the traces. The calculated target solution then matches the observed received energy trace.

Abstract: The invention relates inter alia to a sensor system (50) used for distance calculation. A setpoint selection unit (58) controls an amplifier unit (54) and/or a sensor unit (52) depending on selectable setpoints for a cycle of detection. Contrary to known sensor systems, different detection cycles can be carried out in a very simple manner.

Abstract: In order to locate electromagnetic or acoustic signal sources of a sensor configuration (1a through 1c) fitted with at least two electric outputs; where the incidence-dependent transfer functions between the acoustic signals incident on the input(s) of the sensor configuration (1a through 1c) and the electric output signals are different, the ratio (7x through 7xx) of the output signal is formed and the result then is correlated with the previously determined ratio function (11).

Abstract: A system and method for determining target solutions based on energy received at one or more sensors includes the step of displaying the received energy on a display. Target solution traces are overlaid onto the received energy trace. The operator selects tie-down points, and adjusts at least one of time, range, and bearing definitions for the tie-down points while observing the overlain traces, so as to obtain coincidence of the traces. The calculated target solution then matches the observed received energy trace.

Abstract: An apparatus for ultrasonically detecting an edge of a web, includes a ultrasonic-wave transmitter transmitting ultrasonic-wave pulse train, a ultrasonic-wave receiver receiving the ultrasonic-wave pulse train and converting the received ultrasonic-wave pulse train into electric signals, the web being fed between the ultrasonic-wave transmitter and receiver, a rectifying circuit for rectifying the electric signals, a low-pass filter circuit for smoothing output signals transmitted from the rectifying circuit, a first sample-holding circuit for sampling an output signal transmitted from the low-pass filter circuit, at first timing, a second sample-holding circuit for sampling an output signal transmitted from the low-pass filter circuit, at second timing later than the first timing, a third sample-holding circuit for sampling an output signal transmitted from the first sample-holding circuit, at the second timing, and a differentially amplifying circuit for calculating a difference between output signals trans

Abstract: A method of estimating emitter range and heading from bearing measurements without requiring observer heading change or observer acceleration during the bearing measurement collection period. Emitter signal characteristics are measured and a set of parameters characterizing a specific emitter as a signal source are generated based on the measured characteristics. Based on the emitter characterization and an emitter-platform association data base, a most probable platform including the emitter is identified and the emitter operating mode and corresponding specific platform are associated with a particular kinematic regime.

Abstract: A plurality of sound-detecting devices are configured to detect sound from an event of interest. Information about the sound is recorded that is dependent on a distance between the source position and the location of the sound-detection devices. The source position is approximated using the recorded information and the relative position of individual sound-detection devices to one another. The approximated source position is used as input for operating a electronic device.

Abstract: A system is provided for detecting the presence of two or more acoustic sources or targets such as vehicles that are traveling between an array of unattended passive ground sensors, in which the sensors each include a phased-array microphone and processing to determine the bearing to the acoustic target. The bearings from pairs of these sensors are subtracted one from the other to provide a bearing line difference “delta” which is the indicator of the presence of an acoustic target close to the line between the two sensors of the pair. A tripwire threshold indicating the presence of a target is set when the absolute value of this bearing line difference “delta” is greater than, for instance, 150°, with the “delta” being 180° when the target is on the line between the two sensors.

Abstract: In order to locate electromagnetic or acoustic signal sources of a sensor configuration (1a through 1c) fitted with at least two electric outputs, where the incidence-dependent transfer functions between the acoustic signals incident on the input(s) of the sensor configuration (1a through 1c) and the electric output signals are different, the ratio (7x through 7xx) of the output signal is formed and the result then is correlated with the previously determined ratio function (11).

Abstract: A method and apparatus for analyzing newly acquired and faded or lost sonar contacts. Initial processing identifies a list of possible associations between a newly acquired contact and lost contacts. Subsequent processing of the possible associations reduces the number of possible associations that a sonar operator must consider in determining whether an acquired contact represents a new contact, a reacquired lost or faded contact.

Abstract: A system is provided for detecting the presence of two or more acoustic sources or targets such as vehicles that are traveling between an array of unattended passive ground sensors, in which the sensors each include a phased-array microphone and processing to determine the bearing to the acoustic target. The bearings from pairs of these sensors are subtracted one from the other to provide a bearing line difference “delta” which is the indicator of the presence of an acoustic target close to the line between the two sensors of the pair. A tripwire threshold indicating the presence of a target is set when the absolute value of this bearing line difference “delta” is greater than, for instance, 150°, with the “delta” being 180° when the target is on the line between the two sensors.

Abstract: A measuring system and method of detecting an object distance by transmission media with different wave velocities are described. The measuring system has a computer, a primary detector and a secondary detector. The primary detector is connected to the computer through bus communication and the secondary detector connected to the primary one through two different transmission media. The primary detector is able to receive separately a first signal and a second signal emitted simultaneously from the secondary detector through the transmission media. Moreover, the first signal has light-speed and the second signal has sound-speed. To calculate the distance between the objects which the primary and the secondary detector are attached respectively. The delay time of second signal and the wave velocity of the supersonic media are multiplied.

Abstract: A multistatic passive sonar is disclosed having a time-aligned source combiner, that exploits the cross-correlation between a target beam and all other beams to detect and measure the range of a target. This combiner performs long-term cross-correlation between the target beam and each individual source beam, and then aggregates the individual correlation results, time aligned based on the scenario geometry, and averaged to enhance the composite signal-to-noise ratio of the range measurement. In doing so, innocuous acoustic sources may be opportunistically exploited as if the array were part of a multi-static, active (e.g., sonar) system.

Abstract: A system and method for displaying sonar data are disclosed. In a presently preferred embodiment, each of N channels from a beamformer are separately processed utilizing a pair of passive broadband detection processors such as SCOT processors and SPED processors. The output of each SCOT processor and each SPED processor are scaled, aligned, and then compared. The maximum scaled and aligned output from each pair of processors is selected for input to a bearing time history display.

Abstract: An acoustic signal processor that samples acoustic data, performs a spectrum analysis of the sampled acoustic data, stores the acoustic data in corresponding frequency bins, and then filters acoustic data stored in a frequency bin by applying a power-law arithmetic operation to the frequency bin acoustic data, such that the power-law arithmetic operation is adaptively changed based on an order dependent determination of whether the frequency bin acoustic data is representative of noise or clutter, or whether it is representative of a signal of an object.