Abstract: This invention discloses a tracking and positioning system including a plurality of transmitters distributed within a working space, and at least one sensors attached to at least one moving object and operative to sense transmissions arriving from the plurality of transmitters, a dynamic transmission activator operative to track at least one position parameters of at least one of said sensors and to selectively activate and deactivate individual sets of at least one transmitters from among the plurality of transmitters, at least partly responsively to at leas one position parameters of at least one of the sensors. A tracking method for tracking a moving object whose initial position is substantially unknown is also disclosed.

Abstract: A time/analog converter for adjusting the zero point and amplification of the output characteristic of a sensor includes an integrator whose output is connected to the input of a holding member. A reference voltage and the output voltage of the holding member occur at the input of the integrator. A control means actuates switches connecting the integrator to the holding member and applying the reference voltage and the output voltage to the input of the integrator so that the reference voltage is at the integrator input for a first time interval and the holding member output voltage is at the integrator input for a second time interval. The integrator output voltage is applied to the holding member for a third time interval. A controllable pulse shaper is connected to one of the switches and can close it for a required time interval. A related method is also described.

Abstract: A system which enables the position of each of a plurality of movable labelled objects to be determined in an environment having two or more isolated zones, wherein the objects carry transponders which, in response to encoded radio signals, transmit ultrasonic signals of which the transit times to a plurality of fixed receivers are determined, the transponders in the different zones being triggered in a common timeslot but in staggered relationship for one zone as compared to another, and an algorithm is applied to verify the consistency of the transit times having regard to the possible movements of objects from one zone to another.

Abstract: A method and apparatus using ultrasonic sensors for determination of the pointing vector described by two points separated in space in the coordinate frame of the measuring system. For measurement, acoustic signals are transmitted from two emitters whose spatially separated coordinates form the desired pointing vector. Three detectors, associated receiver electronics and software are required to compute six distinct spheres from the time of flight measurements. The intersection of the three spheres, associated with each emitter, describe the desired location in the detector coordinate system of that emitter. With the coordinates of each emitter, the pointing vector is computed using standard geometry. A reference is required to determine the time of flight of the signals to each detector. Another embodiment uses an active reflective technique, where the timing is obtained through round trip transmission and reception of the signal with a known fixed delay at the vector points.

Abstract: A method and apparatus for distance measurement is disclosed in which first and second signals having different propagation speeds are transmitted between a transmitter (2) at a first location and a receiver (3) at a second location. The distance between the first and second locations is determined from the difference in propagation time between the first and second signals.

Abstract: The invention relates to an apparatus for detecting the position of an object moveable along a predetermined travel path, comprising: an acoustic signal waveguide extending along the travel path and having a predetermined, uniform speed of propagation of sound; a signal input coupler located on the moveable object, to couple a clocked acoustic signal into the acoustic signal waveguide, at least one signal output coupler being arranged at one end of the acoustic signal waveguide and being connected to an evaluation unit for determining the propagation time of the sound signal from a position at which it is coupled in to the at least one signal output coupler and for generating a signal representative of the instantaneous position of the moveable object on the travel path, wherein the signal input coupler couples in, as acoustic signal, adjacent pulses having a varying time interval.

Abstract: The invention relates to an apparatus for detecting the position of an object moveable along a predetermined travel path, comprising: an acoustic signal waveguide extending along the travel path and having a predetermined, uniform speed of propagation of sound; a signal input coupler located on the moveable object, to couple a clocked acoustic signal into the acoustic signal waveguide, signal output couplers at both ends of the acoustic signal waveguide and each being connected to an evaluation unit for determining the propagation-time difference of the sound signal from a position at which it is coupled in to the signal output couplers and for generating a signal representative of the instantaneous position of the moveable object on the travel path, wherein a calibration signal input coupler connected to a calibration acoustic signal generator for a calibration acoustic signal is provided on one of the signal output couplers, the evaluation unit calculating a correction variable for subsequent determinat

Abstract: A method and apparatus using ultrasonic sensors for determination of the pointing vector described by two points separated in space in the coordinate frame of the measuring system. For measurement, acoustic signals are transmitted from two emitters whose spatially separated coordinates form the desired pointing vector. Three detectors, associated receiver electronics and software are required to compute six distinct spheres from the time of flight measurements. The intersection of the three spheres, associated with each emitter, describe the desired location in the detector coordinate system of that emitter. With the coordinates of each emitter, the pointing vector is computed using standard geometry. A reference is required to determine the time of flight of the signals to each detector. Another embodiment uses an active reflective technique, where the timing is obtained through round trip transmission and reception of the signal with a known fixed delay at the vector points.

Abstract: An ultrasonic location system for indoor environments, enabling the determination with high accuracy of the positions and orientations of objects to be tracked, wherein transmitting units (20, 22, 24) on the objects to be tracked transmit encoded ultrasonic pulses which are detected by receiver units (12 to 18) located by known positions around a room, and the receiver units are adapted to detect times-of-flight of the ultrasonic pulses in conjunction with decoding of the pulses to identify which time-of-flight applies to each transmitting unit.

Abstract: A system is provided for determining range to a wave energy source. The system includes a transmitter for transmitting a burst of pulses of wave energy in response to a trigger signal. A receiver is provided for determining a time of arrival of the burst and from such determined time of arrival, the range to the wave energy source. The receiver includes: an envelope detector for detecting an envelope of the burst; a network for producing an output in response to an early point on the detected envelope occurring prior to a peak in the detected envelope; a timer, responsive to the trigger signal and the network output for determining the time of arrival of the burst; and a processor, responsive to such determined time of arrival, for determining the range of the wave energy source from the transmitter.

Abstract: An apparatus for detecting the position of a moveable object along a path such as a rail or a wire. The apparatus includes an acoustic signal conductor, a signal input coupler, and a signal extractor. The acoustic signal conductor extends along the travel path and has a predetermined, uniform speed at which sound is propagated. The signal input coupler is located on the moveable object to couple a clocked acoustic signal into the acoustic signal waveguide. The signal extractor is arranged at one end of the acoustic signal waveguide and is connected to an evaluation unit for determining the propagation-time of the sound signal from a position at which the sound signal is coupled to the signal extractor to accordingly generate a signal representative of the instantaneous position of the moveable object on the travel path. A sensor on the acoustic signal conductor is actuated by being passed over by the moveable object.

Abstract: Signals from microphones 1, 2 are first stored in memory circuits 4, 6 and then supplied to a cross-correlation arithmetic circuit 7, following which a cross-correlation operation is carried out and cross-correlation function values are calculated for each time difference. An evaluation function circuit 8 carries out addition processing of particular time intervals based on the cross-correlation function values and then searches for the maximum value to calculate time differences. Signals from the microphones 2, 3 are first stored in memory circuits 6, 5 and then supplied to a cross-correlation arithmetic circuit 9, following which a cross-correlation operation is carried out and cross-correlation function values are calculated for each time difference. An evaluation function circuit 10 carries out addition processing of particular time intervals based on the cross-correlation function values and then searches for the maximum value to calculate time differences.

Abstract: A system and method for detecting the range of an acoustic source within a reverberant space. The invention includes a method, apparatus, and computer program to determine whether a sound source is situated near or far from a pair of microphones situated within a reverberant space. A signal detector is applied to the data; only the data that passes the signal detector is processed any further. The signal at the two microphones is compared to obtain the angular distribution of acoustic power. The concentration of acoustic power in the direct path versus reverberant paths is determined and used to compute a direct-to-reverberant ratio. If this ratio is greater than a selected threshold, the sound source is determined to be near the microphones. Otherwise, the sound source is determined to be far from the microphones.

Abstract: An apparatus and method for detecting, locating, tracking, or classifying an acoustic energy source located on a far side of a structure is disclosed. In accordance with the present invention, a receiving device samples a plurality of points on a near side of the structure to detect vibrations that result from sound waves propagated by the acoustic energy source. The location of the acoustic energy source is determined based on the relative time differences of the vibrations and the known positions of the vibrations on the structure. The acoustic energy source may be classified based on identifying characteristics of the vibrations. In addition, a device may be provided to transmit a sound wave through the structure. The receiving devices samples a plurality of points on the near side of the structure to detect vibrations resulting from reflections of the sound wave from the object.

Abstract: According to a method and a device for deciding relative to a chosen reference system, and without contact, the position, direction or speed—or any combination thereof—for a projectile (10) in its flight through a gas towards a giver target (30), the position of the projectile in a first plane (35) is decided at a certain distance from the target by means of at least three acoustic sensors (S1, S2, S3) arranged in a vicinity of the plane. Acoustic sound waves, emanating from a turbulent gas volume (13, 14, 15) extending essentially straight behind the projectile (10), and/or emanating from a wake or monopole (12, 13) existing essentially straight behind the projectile, are received by means of the acoustic sensors (S1, S2, S3). Time differences for the arrival of the acoustic sound waves to the respective acoustic sensors are measured. The projectile position (x, y; x1, y1) in the first plane is calculated from the time differences.

Abstract: A low cost and highly accurate sniper detection and localization system uses observations of the shock wave from supersonic bullets to estimate the bullet trajectory, Mach number, and caliber. If available, muzzle blast observations from an unsilenced firearm is used to estimate the exact sniper location along the trajectory. The system may be fixed or portable and may be wearable on a user's body. The system utilizes a distributed array of acoustic sensors to detect the projectile's shock wave and the muzzle blast from a firearm. The detection of the shock wave and muzzle blast is used to measure the wave arrival times of each waveform type at the sensors. This time of arrival (TOA) information for the shock wave and blast wave are used to determine the projectile's trajectory and a line of bearing to the origin of the projectile. A very accurate model of the bullet ballistics and acoustic radiation is used which includes bullet deceleration.

Abstract: A method of localizing signals utilizing auto-correlation functions and cross correlation functions includes: collecting data at a plurality of input channels; filtering the data collected from the plurality of input channels in order to identify a primary signal; identifying at least two lags and at least one reference lag in a function of the data; and estimating relative travel times of the data.

Abstract: Apparatus and methods for rapid and improved accuracy acoustic position determination comprising simultaneous and mutually distinguishable wide-band acoustic transmissions emitted from a plurality of spatially diverse transmitters and reception thereof by one or more receivers. The receivers identify the transmitters by directly (non-demodulated) correlating the received signal against stored or regenerated replicas of the transmitted signals. The location of the receiver is determined relative to the identified transmitter locations according to the measured times-of-flight from the identified transmitters to the receiver. Further embodiments of the method and apparatus of the present invention provides yaw, pitch and roll determination with a plurality of co-located receivers, and an extended and enhanced operating area.

Abstract: A method of tracking an object within a surveillance area having a predetermined linear extent. One or more ultrasound transducers are fixed to the object. A plurality of background units are placed at known positions in the area, each unit including an ultrasound transducer. One or more ultrasound waves are transmitted between the object and the plurality of background units. The ultrasound waves are received if they have propagated between the object and the background units within a time window of a duration such that the product of the duration and the speed of sound is substantially less than the linear extent of the detection area. A characteristic of the received ultrasound waves is determined, and coordinates of the object are determined responsive to the characteristic.

Abstract: The present invention is generally directed to a method of remotely controlling electronic devices by using the change in time required for sound waves to travel from an emitter to a detector. The time needed for emitted sound waves to reach a detector depends on the distance from the emitter to the detector. The present invention uses a system which measures the time between emission and detection of two or more successive sound pulses or sound waves. The change in time for sound waves to travel the distance from the emitter (or emitters) to the detector (or detectors) is determined and then used for controlling electronic devices. The sound waves are produced by a sound generator, and the detector is designed specifically for the detection of sound waves. In certain embodiments, ultrasonic sound waves or pulses are produced by the sound generator and are used to control an electronic device such as a computer cursor or vehicle.

Abstract: An apparatus and method for measuring the true distance and relative velocity between first and second objects. The apparatus comprises a transceiver located at the first object which measures a first transit time for the transmission of a first signal from a first object to a second object and for the reflection of the first signal from the second object back to the first object. The transceiver further measures a second transit time for the transmission and reflection of a second signal, the second signal being transmitted immediately upon the reflection of the first signal back to the first object. First and second transit times can be used to calculate first and second apparent distances between the first and second objects, respectively. The apparatus also includes calculating means for determining the relative velocity between the first and second objects using the first transit time and the second transit time.

Abstract: In a noise measuring system comprising a microphone array and a directivity forming section for controlling the direction of directivity of the microphone array, the directivity forming section includes delay section and adding section, and the optimal value of a delay time of the delay section is set in such a manner that a noise isolation characteristic for causing any mobile noise generator not targeted for noise measurement to come off a directional plane or a directional line formed in the direction of directivity of the microphone array and a deterioration characteristic of the directivity of the microphone array balance with each other.

Abstract: An apparatus (14) for locating a source of acoustic mission in an article (10) comprises a plurality of spaced transducers (18) which supply output signals corresponding to detected acoustic emission activity to a processor (24). Artificially induced acoustic emissions (12) are generated in the article (10) by directing a laser beam (33) onto the article (10). A camera (40) produces an image of the article (10) and any laser flashes. A processor (42) converts the positions of the laser flashes to coordinates on the article (10). A processor (24) analyses parameters of the acoustic emission in the output signals and the coordinates of the laser flashes to infer the mathematical relationship between the parameters and location of acoustic emissions.

Abstract: What is disclosed here is a transmitting and receiving means for ultrasonic waves, comprising a miniaturized ultrasonic generator which operates inendently on a battery and which is appropriate for accommodation in a small encapsulating case for medical examinations, as well as at least one ultrasonic receiver which is connected to an analyzer which determines, with resolution in terms of time, the distance between the ultrasonic generator and the ultrasonic receiver.

Abstract: A method for determining the positions of the N array elements of a random rray to an accuracy sufficient to accomplish beam forming is provided where the initial positions of the array elements are known to an accuracy of .lambda..sub.min/2, and where .lambda..sub.min is the wavelength of the highest frequency of any of the M cohering sources which are in the field of the array and where the relative directions are unknown. The method includes the steps of: identifying M cohering sources in the field of the array, each of which emits at least one narrowband frequency, each frequency differing from the adjacent frequency by 1/T, where T is the time period of the measurements; a device for measuring the true bearing of one of the M sources; receiving the M cohering signals at the N array elements; performing a Fast Fourier Transform (FFT) on each of the N element signals; examining the spectrum of each of the N received signals; and from the N spectra, selecting M (M>3) lowest angular frequencies, .omega..

Abstract: This invention is an automatic gunnery system, responsive to airborne acoustic shock waves produced by a projectile passing through a target area. The invention relates specifically to the "hit" location of the said projectile for the condition when the flight path of the projectile is not perpendicular to the target area. Two pairs of concentric curved elongated acoustic energy conductors (curved sensor rods) are located adjacent to one side of said target area with acoustic transducers attached to the end portions thereof. Said transducers produce an electrical signal when a shock wave from the projectile reaches them through said energy conductors. Electrical signals from the transducers are connected to electronic circuitry and a calculating computer which calculates the intersection of two circles and determines the location of each "hit" on or near the target with each "hit" registered on a graphical display means.

Abstract: A low cost and highly accurate sniper detection and localization system uses observations of the shock wave from supersonic bullets to estimate the bullet trajectory, Mach number, and caliber. If available, muzzle blast observations from an unsilenced firearm is used to estimate the exact sniper location along the trajectory. The system utilizes a distributed array of acoustic sensors to detect the leading edge of a projectile's shock wave and the muzzle blast from a firearm. The detection of the shock wave and muzzle blast is used to measure the wave arrival times of each waveform type at the sensors. This time of arrival (TOA) information for the shock wave and blast wave are used to determine the projectile's trajectory and a line of bearing to the origin of the projectile. A very accurate model of the bullet ballistics and acoustic radiation is used which includes bullet deceleration.

Abstract: The system includes circuitry for measuring the distance between a transmitter and one or more receivers, and having a timing circuitry to measure the time-of-flight of an RF pulse and the transversed distance of the pulse. The use of two receivers in a single plane provides for the determination of the location of the transmitter with respect to a reference position created by the associated tracking system and the automatic tracking of the transmitter with the field of view of a camera by the tracking system.

Abstract: A coordinate input apparatus which can stably input coordinates at a high precision is provided. A vibration sensor is fixed to a vibration propagating plate by means such as an adhesion or the like. Electrodes are formed on both edge surfaces of the vibration sensor. One electrode is connected to the vibration propagating plate (its surface is made of a conductive material). Another electrode is connected to a conductive plate spring through an electrode leading member. The electrode leading member has a cylindrical portion to position a projecting portion to a center axis by setting a side surface of the vibration sensor to a reference has a relation adapted to be come into engagement with the vibration sensor. The plate spring presses the electrode leading member to the vibration sensor and is electrically connected to the vibration sensor.

Abstract: A novel multi-lane traffic monitoring system is based on detecting the acoustic signals motor vehicles create and radiate during operation. The system comprises an array of electro-acoustic sensors for converting impinging acoustic wavefronts to analog electrical signals; a circuit to acquire, perform signal frequency component discrimination, and digitize the electrical signals at the electro-acoustic sensor array output; a circuit to perform effective spatial discrimination in the up/down road direction and in the cross-road direction in real time; a circuit to perform vehicle detection for individual lanes and to estimate or measure pertinent parameters associated with each vehicle detection from each traveled lane; and a circuit to compute for each lane, pertinent traffic flow parameters from vehicle parameters for the purpose of providing a transportation system interface.

Abstract: A projectile trajectory and source location system and method identifies, calizes, and displays a projectile trajectory relative to one or more stationary objects, such as buildings in an urban environment. The system includes a sensor array and trajectory location calculator that sense conditions generated by the projectile, such as an acoustic signature, and calculate a set of ranges to the trajectory. A ranging system and range comparison calculator measure ranges to one or more stationary objects and compare those ranges to the set of ranges to the trajectory. A display displays the trajectory relative to the stationary objects including unobstructed portions of the trajectory, obstructed portions of the trajectory and the located source of the projectile. A tracking system and dynamic reprocessor track the movement of an observer, dynamically reprocess the relative trajectory location, and update the display of the relative trajectory location in response to the observer's movement.

Abstract: A method for locating structure-borne sound events in pressure enclosures to be monitored in power plants, includes positioning sensors at various locations on a pressure enclosure. Signals are picked up with each of the sensors upon arrival of a sound wave generated by a structure-borne sound event and propagating along the pressure enclosure. The signals are stored in recording devices disposed downstream. A location of the structure-borne sound event is determined with a hyperbolic section method, from transit time differences resulting from different arrival times of the sound wave at two different sensors. Each range of possible speed values for the propagation of the generated sound wave is made a basis of one respective structure-borne sound event. The hyperbolic section method is performed separately for each speed value of the range for outputting a location indication with an error. The location with the least error is selected as the most likely location of the structure-borne sound event.

Abstract: A method for selecting a set of four target bearings from a plurality of bearing measurements to optimize rapidity, accuracy and stability of a target track solution in a bearings-only target motion algorithm. Four bearings are selected to generate the deterministic solution by first selecting a candidate bearing set, then computing a set of "n" solutions from the candidate set and others adjacent thereto. Motion parameters are then computed, and any solution exhibiting parameters outside a user defined deviation from the mean is discarded. The mean target parameters of the remaining solutions may again be computed, and further culling out performed, until the desired distribution is achieved. An optimal solution is chosen as the solution from the remaining sample space that is closest to the mean in target range, course and speed.

Abstract: A digitizer uses acoustic waves originating from a stylus to determine the position of the stylus on a plate. The acoustic waves are introduced into the plate from the tip of the stylus and are detected by a plurality of detectors positioned at various points along the periphery of the plate. By sensing differences in the arrival times of the acoustic waves at the detectors, a microprocessor calculates the position of the stylus. In a preferred embodiment using a non-tethered stylus, four detectors are positioned at the corners of a rectangle, and the time differences are used as addresses in a lookup table, which is programmed to contain x and y coordinates corresponding to the time differences, Different embodiments may detect only the "fast" symmetrical waves or only the "slow" antisymmetrical waves generated in the plate, or may use the arrival times of both types of waves to determine the stylus position.

Abstract: A method for determining the position of seismic equipment wherein acoustic transmitters transmit spread spectrum sequences which are received by the seismic sensors in the equipment whose position has to be determined. By collecting and processing the signals thus produced, it is possible to determine the position of seismic equipment with reference to each individual sensor in the seismic equipment each time a measurement is take. The already existing conventional seismic sensors which are provided in a streamer are used to record the transmitted spread spectrum signals. By calculating time differences between the sensors' reception of a spread spectrum signal it is possible to calculate the position of the seismic equipment.

Abstract: A short baseline navigation system employs the real-time estimation of the positions of multiple cooperative targets. Each target replies with a unique stepped frequency sequence signal that covers the usable frequency band. A processor operates on reply signals received by elements on the tracking platform and develops a coarse time-difference-of-arrival estimate using an algorithm derived herein. The processor also estimates the Doppler shift of received signals, and determines a time-window (or gating) that eliminates the portions of the received signals corrupted by multipath interference. The relative phase differences between the received signals are then used in conjunction with the coarse time-difference-of-arrival estimates for a precise direction-of-arrival estimation.

Abstract: In a coin handling apparatus, a single sensor (30) detects impacts of the coin at different positions within the apparatus, and uses the output to determine the route taken by the coin through the apparatus, and the speed of the coin.

Abstract: The disclosure involves a method for guiding a machine within an area. Such method includes the steps of triggering an acoustic locating signal from a stationary "beacon-type" base module to a receiver on the machine. The method is applicable for one-beacon, two-receiver and two-beacon, one-receiver applications. A related apparatus also includes a device for emitting a trigger signal and a device for determining the time elapsed between transmission and reception of the locating signal. An operating principle involves computing the module-to-machine distance by determining the "time of flight" of such signal. The machine is steered along a path, the locus of which is defined by an equation.

Abstract: This invention relates generally to a method and system for synchronizing the timing of events between and among vessels using a common timing reference.

Abstract: A method and apparatus for determining position of a vehicle in a tank of fluid. At least one transducer is disposed on the vehicle and a plurality of transducers are disposed on the outside wall of the tank. The transducers are arranged in a substantially common plane. The travel time of energy can be measured between any two of the transducers. Accordingly, the velocity profile of the liquid can be determined based on travel times measured between the transducers on the tank and position can be determined based on travel times measured between the transducers on the vehicle and the transducers on the tank.

Abstract: An apparatus and method for accurately determining the relative locations of sensors in a passive sonar or like monitoring system utilizes two non-parallel (but not necessarily orthogonal) calibrator signals to calculate the relative positions of sensors in a sensor array. Iteration, using a deformed line array constraint, permits reliable solution of the sensor position equations, even when the relative angle between the calibrator signals is initially unknown.

Abstract: An automatic noise threshold circuit and method automatically sets an operating threshold for a signal receiving section of a laser pulse transmitting device such that a constant noise pulse firing rate is output from a detector to provide maximum return signal sensitivity and enable detection of the weakest possible laser pulse in order to obtain maximum performance out of a laser range finder. The circuit sets the noise pulse rate at that point at which, in conjunction with a firmware based process, the actual return signals from the target can be discrimintated from the accompanying noise.

Abstract: New apparatus comprise a optical fiber based RF signal train generator for storing transient RF pulses and regenerating the identical replicas for analysis. The apparatus further comprise RF receivers to process one stored pulse with a reference to other stored pulse. The present invention drastically increases our abilities to investigate acoustical, electromagnetic, and optical transient phenomena.

Abstract: Location of a firearm firing projectiles is accomplished by using an acoustic detection antenna that includes at least three microphones spaced apart from one another to detect and record signals and time offsets of the signals which are representative of the muzzle noise of the firearm and/or the soundwave emitted by the mach cone generated by a projectile that has supersonic muzzle velocity, and processing the signals and their time offsets in such a manner as to determine at least the direction in which the firearm is located.

Abstract: A range-finding system for measuring a target distance from a point of measurement to a target object, comprising a slave unit for calculating and indicating the target distance based on a waiting time from transmission of an interrogation signal to reception of a response signal and a master unit placed at a certain correction distance from the target object for transmitting the response signal when a delay time corresponding to the correction distance has elapsed from reception of the interrogation signal.

Abstract: An acoustic tracking system designed to allow scientists and fishermen to follow dolphins and whales without harming or harassing them. The system utilizes six flow shielded hydrophones mounted on the bottom of a vessel in two arrays of three hydrophones in each array. Acoustic signals of interest (dolphin calls) which strike the hydrophone piezo-electric elements are transmitted to a receiver-display device which determines and displays both the bearing to the signal of interest and the relative range from the vessel to that signal. The receiver-display device utilizes digital microprocessors to determine the difference in signal arrival time of an incoming signal at pairs of hydrophones. The resulting computed bearing to the dolphin call is displayed as a lighted indicator on an electronic heading display.

Abstract: Methods and apparatus are provided for determining the general direction of the origin of a projectile. At least one sensor, having at least three spaced-apart transducers, each being capable of encountering a blast wave generated at an origin of and by a propellant for the projectile, is provided for generating a signal responsive thereto. From the signals, a time relation is measured between at least three transducers when the blast wave serially encounters each of the three transducers. From the time relations, at least one unit sighting vector from at least one sensor to the origin of the blast wave is determined so that the unit sighting vector points in the general direction of the origin of the projectile.

Abstract: A piezoelectric sensor for detecting elastic plate vibrations in an object such as the transmission plate in a coordinate input apparatus is prismatic in shape and is fixed to the surface of the object. The prismatic sensor is arranged so that it is parallel to the direction of propagation of the vibrations and has an electrode surface perpendicular to the surface of the object. The arrangement of the prismatic sensor permits the thickness of the object in which the plate vibrations propagate to be substantially reduced and reduces the manufacturing cost of coordinate input apparatus using the prismatic sensor.

Abstract: New apparatus comprise a comprises an optical fiber based RF signal train generator for storing transient RF pulses and regenerating the identical replicas for analysis. The apparatus further comprise comprises an RF receivers receiver to process one stored pulse with a reference to other another stored pulse. The present invention drastically increases our abilities to investigate acoustical, electromagnetic, and optical transient phenomena.

Abstract: A system is disclosed for determining the location from which a sound blast having an identifiable audio signature originates. The system is particrly suited for determining the location of the muzzle blast from which a projectile, such as a bomb, is being launched by an enemy. The system comprises a plurality of elevated or airborne sensors whose position is accurately determined and which supply information to a land base station that performs the trigometric operations to ascertain the location of the enemy weapon.