Abstract: An apparatus for detecting the discharge of a firearm and transmitting an alerting signal to a predetermined location. The invention provides for detection circuitry having: (1) a microphone for detecting pre-set sensitivity levels, (2) a measuring means for measuring acoustic energy generated from the discharge of the firearm, resulting in acoustic energy information, (3) transferring means for transferring the acoustic energy information to a digital signal processor, which converts the acoustic energy information into digital format, resulting in digitized binary codes, (4) an analyzing means for comparing the digitized binary codes contained in the digital signal processor with a set of predetermined criteria, (5) a verification process, and (6) an alerting means for transmitting an alerting signal to a predetermined location in the event the digitized binary codes match the set of predetermined criteria.

Abstract: A method is described to determine the position of one or more snipers when a listening station is located in the target area, and when the snipers are randomly located. The intelligent listening system can be located at a stationary or mobile platform, consisting of a minimum of 2 microphones in the combination with a compass. The listening station registers shot sound from the sniper weapon and the shock wave from the projectile trajectory. These two signals are utilized to determine the north adjusted direction to the weapon and the shock wave. The position of the weapon is determined when utilizing the speed of the projectile and the time difference between the shot sound from the weapon and the shock wave. The position is determined as the distance along the direction vector from the listening station and to the sniper weapon. Additionally the closest distance to the trajectory of the projectile is determined.

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 covert aircraft detection system for a submarine is described which inces an acoustic antenna array and a signal processor to process the acoustic signals to provide the location of the detected aircraft and to classify the detected aircraft. The acoustic antenna array is mounted on the submarine mast and includes a vertically extending rod having a microphone and connected thereto three or more folding legs having microphones connected thereto. The microphones detect the aircraft acoustic signals and these signals are transferred to the signal processor which provides the location of the aircraft and matches the acoustic signal with the database of aircraft acoustic signals to classify the type of aircraft. When the acoustic antenna array is connected to a rotatable mast, such as a periscope, a rotary encoder and mast bearing indicator are utilized to account for the rotation of the acoustic antenna array and the rotation of the mast, respectively.

Abstract: A security system for detecting a gunshot event. A communication link, and a number of pole units are arranged in a dense grid. Each one of the pole units includes a microphone and a signal conditioning and thresholding unit coupled to the microphone. The signal conditioning and thresholding unit outputs a detection signal in response to an event when an output signal from the microphone exceeds a peak background average. A data acquisition and signal processing unit is coupled to the signal conditioning and thresholding unit for discriminating gunshot events. The data acquisition and signal processing unit remains in a powered down stand-by mode so as to conserve energy until a detection signal is received. The data acquisition and signal processing unit includes apparatus for identifying a gunshot event by measuring an initial pulse time duration and subsequent pulse pattern features, and a communication interface coupled at an input to the data acquisition and signal processing unit.

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: 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 security system for detecting and reporting gunshot events for control of urban environment security which includes a communication link coupled to a plurality of pole units arranged in a dense grid. Each of the plurality of pole units includes a microphone, a data acquisition unit coupled to said microphone, a signal processor for discriminating gunshot events, and a communication interface apparatus coupled at an input to the signal processor. The communication interface also has an output coupled to the communication link, where the communication interface transmits and receives data on the communication link. A central processor is coupled to the communication link so as to receive data from and transmit data to the plurality of pole units. The central processor and the plurality of pole units operate so as to detect and locate gunshot events sensed by one or more of the plurality of pole units.

Abstract: An acoustic sensor for measuring acoustic waves contained in fluid flow flowing over the sensor. The acoustic sensor reduces any unwanted self-noise associated with the flowing fluid by providing a nose cone having proper aerodynamic properties and by positioning the diaphragm of a microphone of the sensor at a location where any unwanted noise is at a relatively low level. The nose cone has a rounded, blunt or even sharp tip neither of which creates any major disturbances in the flowing fluid which it intercepts.

Abstract: An amplitude responsive detection system analyzes the amplitude characteristic of a received noise and determines whether that characteristic conforms to the predictable audio signature of a gunshot. If a received noise reaches a predetermined amplitude level within a rise time that may be indicative of a gunshot, subsequent amplitude criteria are established representing the decay of the amplitude profile that is expected if the noise is a gunshot. The amplitude criteria are controlled as to both level and occurrence in time to provide a dynamic range that will accommodate near and far gunshots.

Abstract: Optical frequency encoding for normal shock and position sensing where the modulated signal is coupled to a single fiber as a sum total of all the wavelength components.

Abstract: Optical frequency encoding for normal shock and position sensing where the modulated signal is coupled to a single fiber as a sum total of all the wavelength components.

Abstract: This invention is concerned with an indicator apparatus for determination of the trajectory or the trajectory direction of a projectile travelling at supersonic speed. It comprises pressure sensitive transducers (T.sub.1 -T.sub.4), which have fixed positions relative to each other or move relative to each other in a defined way, and which are devised to measure the pressure wave generated by the projectile. Also, there are means to produce electrical signals from the transducers, which represent the pressure values sensed by the transducers. Using said signals from each pressure transducer the computing circuits determine a value for a time instance when the pressure wave pass the transducer. From these time values and the geometrical quantities, which specify the position of each transducer in relation to a spatial coordinate system, the computing circuits evaluate the direction of the projectile trajectory more or less accurately.

Abstract: Apparatus and method for the electro-acoustical measurement of the angle ection of passing projectiles at air-tow-targets, wherein at least three acoustical sensors are equidistantly positioned on a fixed sensor ring which is supported by the tow-target, wherein the arrival times of the waves of the projectiles are electronically measured by means of the several sensors.

Abstract: Apparatus and method for determining the trajectory of a supersonic projectile of unknown velocity and direction having at least three spaced-apart sensors capable of encountering a shock wave generated by a supersonic projectile passing in the vicinity of the sensors and capable of generating signals in response to the shock wave, which signals are related to an azimuth and elevation angle of a unit sighting vector from each sensor to an origin of the shock wave. Means are provided for calculating from the signals the azimuth and elevation angle of the unit sighting vector from each sensor to the origin of the shock wave. Means are provided for calculating from the unit sighting vector of each of the three sensors, the azimuth and elevation angle of the local trajectory of the projectile.

Abstract: A monitoring system for monitoring window panes of an interior of a space or chamber having a plurality of window panes and lateral and/or upper and/or lower walls surrounding the window panes, such as an interior of a motor vehicle to be monitored for intruders, includes at least one microphone configuration for detecting vibrations typically produced when a pane is broken. The microphone configuration is fastened in the interior and/or to at least one of the walls of the space in each case without mechanical contact with the window panes to be monitored, in such a way that the respective microphone configuration can receive essentially only the vibrations transmitted by the air in the interior. The number of the microphone configurations used to detect acoustic vibrations typically produced when a pane is broken and transmitted by the air in the interior is less than the number of window panes and/or door panes and/or roof panes to be monitored for pane breakage.

Abstract: A fiber optic-type shock wave sensor automatically adapts itself in response to vibration preventing false shock wave detection signals. The sensor includes a sensor element comprising a pair of mating toothed rings and a fiber optic coil disposed between the teeth of the rings. One of the toothed rings is moveable in response to shock waves to cause a bending of the fiber optic coil which detectably alters its light transmission characteristics. A rigid, dome shaped membrane is attached to the moveable ring and is flexibly attached to a body containing the sensor element. The membrane and body form an enclosure for the sensor element, and an aperture is disposed in the body which communicates with the enclosure. A normally closed spring biased check valve covers the aperture, and opens in response to a reduction in pressure in the enclosure to admit additional air or gas to the same.

Abstract: The miss distance of a projectile aimed towards a target is determined by a line of pressure transducers other than microphones which through response to a sudden pressure change together establish a cone section through a passing Mach cone; and the time space analogies of that cone permits reconstruction of the projectile path being in effect the axis of that cone.

Abstract: This invention is an automatic gunnery system, responsive to airborne acoustic shock waves produced by a projectile passing through a target area. Curved elongated acoustic energy conductors 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 signal from the transducers is connected to electronic circuitry which determines the location of each "hit" on or near the target which is registered on display means.

Abstract: An analyzer recorder collects sonic boom information of supersonic aircraft and launch vehicles, for use to validate Environmental Impact Statements that contain supersonic aircraft activity. The device comprises a 16-bit microprocessor, a random access memory (RAM) storage, a data retrieval unit (DRU), and a microcomputer. It samples and captures in digital form any loud impulse noise from background noise. The unattended device can discern a sonic boom from the normal background noise and capture it in permanent solid RAM storage for later analysis. The RAM modules can then be transferred with the DRU and the information on the DRU transferred to the microcomputer. The microprocessor displays each recorded event, time of occurrence and summary information for all the stored data.

Abstract: The position of a projectile travelling at a supersonic velocity is sensed by two triangular arrays of transducers 10,11 which are located below and close to the plane of a target area 14 through which the projectile passes. Signals from the transducers are processed to obtain data indicative of the direction of the trajectory from each array. This data can be processed to obtain the position of the trajectory in a cartesian coordinate system.

Abstract: An aircraft detection system which detects and tracks aircraft using: arrays of seismic and acoustic sensors, a set of junction circuits, a set of subarray circuits, several slave computers, and a master computer. Each junction circuit relays detected signals from several adjacent sensors to a subarray circuit and command signals to each of the sensors to adjust the gain of their output signals. Each subarray circuit receives and unites the outputs of several adjacent junction circuits into a subarray which has a particular geographical location in the array of sensors. Each slave computer forwards detected signals from single subarray circuit to the master computer, and relays command signals back to each individual sensor. Each subarray is able to track the seismic or acoustic signature of an aircraft as it travels across the regular distribution of sensors. Each subarray is thereby able to define an azimuth to the target aircraft.

Abstract: The minimum distance between a passing projectile and a training (dummy) target is ascertained by means of four shock wave responsive transducers in the target, two of which are aligned with the target's propagation and the transit time differential of receiving the shock wave from the projectile as well as measured distances to the projectile's trajectory are used to establish a set of possible projectile trajectories, one of them being the real one; all of them being arranged in rotational symmetry to the line established by the two transducers. This information suffices already to determine the minimum distance of fly by.

Abstract: A target bag to be towed has on its periphery arranged a plurality of pressure sensitive transducers for monitoring the trajectory of passing projectiles. The transducers are arranged to obtain overall omnidirectional response characteristics in relation to the center of the target.

Abstract: An apparatus for use in a firing range, in which transducers located adjacent the target area detect the airborne shock wave from supersonic projectiles. The position at which each projectile passes through the target plane is determined from the relative time of arrival of the associated shock wave at the transducers. A visual display of the target and the projectile position is provided for the use of range personnel.

Abstract: There is disclosed a system for guiding, positioning, and measuring through robot control, a tool and a work zone relative to each other, by a noncontacting probe of at least one transceiver for generating shock waves, and for sensing their reflections, with one or more multiple apertured lenses for focusing and concentrating such shock waves and their reflections.

Abstract: An apparatus for use in a firing range, in which transducers located adjacent the target area detect the airborne shock wave from supersonic projectiles. The position at which each projectile passes through the target plane is determined from the relative time of arrival of the associated shock wave at the transducers. A visual display of the target and the projectile position is provided for the use of range personnel.

Abstract: A mounting device 10 for securing a microphone pick-up head 12 flush with respect to the external surfaces of the skin 14 of an aircraft A for detecting shock waves passing thereover. The mount includes a sleeve 30 mounted internally of the aircraft for capturing and supporting an electronics package having the microphone pick-up head attached thereto in a manner such that the head 12 is flush with the external surface of the aircraft skin and a pressure seal is established between the internal and external surfaces of the aircraft skin.

Abstract: Disclosed is an apparatus for training in marksmanship. The apparatus uses a computer to determine the position of strike of a projectile on a target and further detects a hit on the target, especially in the region of the edge of the target where the projectile position determination computer may produce some errors. The physical hit detection system of the present invention will "override" the computer in those instances where the projectile barely touches the edge of the target and the computer "sees" the projectile as having missed the target or vice versa.

Abstract: Disclosed is an apparatus for indicating the location in a measurement plane through which a projectile passes. The apparatus includes an array of at least three transducers responsive to the airborne pressure wave produced by the projectile and positioned at predetermined locations along a line parallel to the movement plane. The apparatus further includes a device for measuring the velocity of the projectile and another for measuring the velocity of sound in air in the vicinity of the transducers. A computing means, responsive to the array of transducers, the velocity measuring means and the propagation of sound determination is provided which determines the location in the measurement plane through which the projectile passed and provides an output indicating that location. Also disclosed is a means, in combination with the position detecting means, for detecting and providing a positive indication of a projectile hit on a target member.

Abstract: Disclosed is an apparatus for use in marksmanship training. The apparatus includes means for detecting and indicating a position in a measurement plane in the vicinity of a target through which a projectile passes. In addition, the apparatus includes means for measuring the velocity of the projectile in the vicinity of the target. The measured velocity is compared with a predetermined expected velocity to determine if the projectile passed through the measurement plane in free flight or if it had ricocheted prior to passing through the measurement plane. The apparatus will then afford the marksman both an indication of where the projectile passed relative to the target and an indication of whether the projectile has struck the target on a ricochet.

Abstract: A curved, elongate transducer assembly contacted by a shock or pressure wave transmits the resultant vibrations to the ends of the member, the vibrations at the respective ends being converted to output signals from which a time difference signal is produced. A computer calculates from the time difference signal the inclination angle of the projectile trajectory relative to a reference line. Two of the curved, elongate transducer assemblies at spaced locations permit calculation of two such inclination angles and, therefrom, the location at which the projectile trajectory passes through a reference plane. The transducer assembly may be a rigid bar with transducer elements at each end, or a single piezoelectric member with pickup electrodes at each end.

Abstract: A hit detection device for use in a marksmanship evaluation device for providing positive and negative reinforcement of shooting techniques immediately after each shot is fired. The hit detection device comprises a transducer spaced apart from a target member and detects and provides a hit indication output when the target is hit. In a preferred embodiment, the transducer in combination with electronic circuitry provide discrimination such that a hit indication output is only provided when the target member is actually hit by a projectile directly and no output is provided if the target is hit by a ricochet or is disturbed by any other external source such as the wind, sonic booms, etc. In a further preferred embodiment, the target member is three-dimensional and at least partially surrounds the transducer to shield the same from air pressure disturbances caused by projectiles passing by but not actually hitting the target member.

Abstract: A target apparatus, having a framework covered by sheets of material to form a chamber the sheets of material being penetrable by a projectile, such as a bullet, fired at the target. A plurality of transducers are positioned at respective spaced-apart locations within the chamber and lying on an arc of a circle, for detecting shock or pressure waves in the chamber caused upon penetration of the sheets of material by the projectile. Time differences between instants of detection of a shock or pressure wave by the transducers are measured, the location at which the projectile penetrated the sheet of material being determined from the time differences. Preferably, a bull's-eye or aiming mark is provided on the target, the center of which is aligned with the center of the circle on which the transducers lie. Apparatus is also disclosed for determining the speed of sound in air within the chamber, enabling the projectile penetration point to be determined with particular accuracy.

Abstract: Probe method and means are disclosed for guiding and positioning a robot-actuated tool, such as a gripper or a welding head, through at least one transceiver for generating and sensing focused shockwaves, the probe being associated with the tool for relative movement with respect to the object or objects being sensed, without physically contacting the same.

Abstract: Indicator apparatus for determining the miss distance of a projectile in relation to a fixed or moving target, comprising pressure-sensing transducers intended to sense the pressure wave generated by the projectile in at least four points, and means for generating corresponding electrical signals therefrom. The apparatus further comprises computer circuits, calculating the distance to the point of origin of the wave, i.e. the so-called "bang generation point", in response to the characteristics of the pressure wave. This distance has been called the "miss distance" in previously known indicator apparatus, but in accordance with the invention the miss distance is defined as the shortest distance between the projectile and target, and one object of the invention is to indicate this distance and the exact position of the projectile when it is at the miss distance from the target.

Abstract: In a target equipment in which transducers are provided to detect the pressure wave generated by a projectile the transducers being connected to a timing and calculating device adapted to calculate from the time delays between the instants of reception of the pressure wave the trajectory of the projectile, a signal transmitter, comprising a spark generator, is used to transmit sonic signals which are detected by the transducers. The signal transmitter can be used to indicate the precise location or shape of the target and this information is stored in the computer memory.

Abstract: In a target equipment in which transducers are provided to detect the pressure wave generated by a projectile the transducers being connectead to a timing and calculating device adapted to calculate from the time delays between the instants of reception of the pressure wave the trajectory of the projectile, a signal transmitter, comprising a spark generator, is used to tansmit sonic signals which are detected by the transducers. The signal transmitter can be usd to indicate the precise location or shape of the target and this information is stored in the computer memory.

Abstract: Apparatus for training in marksmanship which provides positive and negative reinforcement of shooting techniques immediately after each shot is fired. The reinforcement may take a number of forms, preferably comprising a plurality of indications concerning each shot fired. The indications may comprise at least an approximate indication of where a projectile fired at a target has passed relative to the target and/or a positive indication of whether the projectile has actually hit the target and/or whether the projectile has ricocheted prior to reaching the zone of the target. Specific apparatus for performing each of these functions is disclosed. Indication may also be given concerning whether the trainee marksman is correctly gripping the weapon being fired.

Abstract: An improved ballistic impact sensing and display system is provided for use in conjunction with land or water ordnance ranges. A plurality of sensors placed around the target area detect the shock wave created by the impact or passage of the ballistic projectile. The sensors drive electronic timing means which record the time intervals between activation of the sensors by the propagating shock wave. Storage registers within the timing means drive a gridwork of display buses arranged along hyperbolic curves. A matrix of indicators bridging the points of intersection of the hyperbolic buses display the compartment within the target area in which the impact occurred. Additional indicators around the periphery of the matrix of indicators display the sector by which a projectile passed if it missed the target area.

Abstract: A target device for ascertaining the proximity of a hit to the target center comprises a plurality of transducers separated from one another in a space behind the target surface and positioned to respond to the impact shock at times determined by the sound propagation velocity in the air of this compartment. To increase the accuracy of the device, means is provided to provide an essentially constant temperature gradient (or uniform temperature) in the space or compartment and/or one sensor more than that required for determining the position of impact when the sound propagation velocity is known, is used.

Abstract: An apparatus for use in a firing range, in which transducers located adjacent the target area detect the airborne shock wave from supersonic projectiles. The position at which each projectile passes through the target plane is determined from the relative time of arrival of the associated shock wave at the transducers. A visual display of the target and the projectile position is provided for the use of range personnel.

Abstract: To determine the position of a bullet relative to a target an array of at least six transducers is provided, the transducers being in two parallel rows of three in a common plane. The instants of detection of the shock wave generated by the bullet are measured and the position of the bullet is calculated from the measured values.

Abstract: A hit detection device for use in a marksmanship evaluation device for providing positive and negative reinforcement of shooting techniques immediately after each shot is fired. The hit detection device comprises a transducer spaced apart from a target member and detects and provides a hit indication output when the target is hit. In a preferred embodiment, the transducer in combination with electronic circuitry provide discrimination such that a hit indication output is only provided when the target member is actually hit by a projectile directly and no output is provided if the target is hit by a ricochet or is disturbed by any other external source such as the wind, sonic booms, etc. In a further preferred embodiment, the target member is three-dimensional and at least partially surrounds the transducer to shield the same from air pressure disturbances caused by projectiles passing by but not actually hitting the target member.

Abstract: The system is a remotely operated, autonomous multi-channel time history recording device which uses digital and computer technologies to detect, record and display the results of tests that are time varying dependent. It is particularly suited to monitoring the effects of exploding warheads. By placing a series of piezoelectric detectors in an exploding shock wave field, it is possible to ascertain the wavefront propagation. A dynamic peak detector is used is used with each piezoelectric detector to detect the exact peak of the unknown pulse which peak defines the "time-of-arrival" of the pulse. By controlling the system with a computer program it is possible to display the complete time history of the propagating shock wave. When the exploding device is detonated a counter increments in 100 ns steps with its output on a timing bus.