Bbn Technologies Corporation

Raytheon Bbn Technologies Corp.

Gte Internetworking Incorporated

Bbn Corporation

Bolt Beranek and Newman Inc.

Gte Service Corporation

James Edwin Barger

Stephen Douglas Milligan

Marshall Seth Brinn

Richard James Mullen

Ronald Bruce Coleman

Gregory L Duckworth

Douglas C Gilbert

John N Stanley

Scott Evan Ritter

Bruce Stuart Murray

Richard Madden

Daniel Ramsay Cruthirds

Carey D Bunks

Daniel L Nelson

Daniel L Hamel

Stephen D Milligan

Seth Marshall Brinn

John Stanley

The systems and methods described herein include an acoustic sensor having piezoelectric material housed in a cartridge and sealed with a solid nonporous stainless steel cover. The systems include additional elements to tune the performance of the acoustic sensor for measuring shockwaves on the surface of an aircraft, such as a helicopter. In particular, the system includes several vibration isolating elements including foam pads and O-rings disposed between the cartridge and the cover for isolating the piezoelectric material from aircraft vibration and turbulence. Additionally, the systems and methods include circuitry for converting analog electrical signals generated by the piezoelectric material, in response to acoustic signals, to digital electrical signals.

Acoustic sensors for detecting shooter locations from an aircraft

The systems and methods described herein relate to an airborne shooter detection system having a plurality of sensors coupled to the body of an aircraft such as a helicopter. The system includes at least five sensors configured and arranged to disambiguate the location of a shooter. By measuring the arrival times of the shockwaves of projectiles at each of the sensors and determining the differences in the arrival times among sensors, the systems and methods may determine the location of one or more sources of the projectiles. A distance of at least ten meters separates two or more of the sensors. Such a separation is advantageous because it allows the system to disambiguate multiple shooters by resolving the curvature of the shockwave.

System and methods for detecting shooter locations from an aircraft

The systems and methods described herein provide military personnel with a swift and accurate means to return fire at a detected shooter. In particular, the systems and methods described herein relate to an indicator for a weapon sight. In some embodiments, the indicator is electromechanical. In some embodiments, the indicator is configured to be moveable such that when the weapon sight is aligned with the indicator, the weapon points in the direction of the detected shooter. In some embodiments, the indicator is attached to the weapon itself, while in other embodiments, the indicator is attached to the weapon mount. The weapon may be located on a ground vehicle, aircraft, or may be portable. In some embodiments, the system includes a processor configured to receive a shooter's location, determine the position of the indicator based on the received shooter location, and control the indicator to move into the determined position. In some embodiments, the system may provide the location of more than one shooter to military personnel and the location of the second shooter may be provided in the form of an aural or visual signal.

Systems and methods for an indicator for a weapon sight

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

Systems and methods for disambiguating shooter locations with shockwave-only location

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

Self calibrating shooter estimation

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

System and method for identifying a muzzle blast using a multi-sensor total energy approach

A sensor assembly suitable for use in an airborne shooter localization system. The sensor assembly has a pressure sensor subassembly with a pressure transducer positioned to detect pressure variations associated with a shock wave from a passing projectile or the muzzle blast following the shock wave. To substantially increase the signal to noise ratio for measurements of the shock wave, the pressure sensor subassembly attenuates pressure fluctuations triggered by turbulent airflow over the surface of the subassembly more than it attenuates the shock wave. This preferential attenuation is provided by separating the pressure transducer from the surface of the sensor assembly by a cavity large enough that the pressure fluctuations are substantially attenuated as they propagate across the cavity. Additionally, features of a housing that holds the pressure sensor subassembly facilitate use on an aircraft. Those features include flexibility that allows the sensor assembly to conform to curved surfaces, a skin that provides resistance to environmental conditions and allows the sensor assembly to be attached with an adhesive, and a body region that provides high vibrational impedance to prevent low frequency mechanical vibrations from being coupled to the pressure transducer.

Sensor for airborne shooter localization system

Systems and methods for determining shooter locations with weak muzzle detection

The invention in various embodiments is directed to systems and methods for mitigating damage from a shock wave using a gas having a specific impedance less than air.

Systems and methods for explosive blast wave mitigation

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

System and method for disambiguating shooter locations

Systems and methods for compensation of sensor degradation in multi-shooter detection systems are described. In such systems, shooter position and trajectory can be estimated precisely from the shockwaves produced at the plurality of sensors by the incoming shots. However, sensor positions can shift and the performance of some sensors may degrade for various reasons. To compensate for sensor degradation that may occur over the life of a long-deployed system, the shooter estimation algorithms are dynamically adapted by performing a least-squares regression analysis of the shockwave arrival times to obtain a time residual for each shot, observing multiple shots, and weighting the individual contributions of the sensors as a function of the time residuals for the multiple shots.

Systems and method for compensation of sensor degradation in shooter detection systems

Systems and methods for locating the shooter of supersonic projectiles are described. Muzzle blast signals are neither sought nor required. The system uses at least two sensors, with each sensor having a 3-axis accelerometer. The sensors are spaced apart at least 1 meter and have each a diameter of about one centimeter. The three accelerometer signals of each sensor represent pressure gradients and are processed to find the shockwave arrival angle unit vector, the shockwave arrival time instant and peak pressure. Noise signals seldom cause false detections with this sensing method because the sensors have maximum sensitivity at the high frequency characteristics of shockwaves, while their sensitivity to the low frequency characteristics of ambient noise is relatively low.

Compact shooter localization system and method

The invention provides, in various embodiments, a transducer for generating hyper-directional sound beams, and a system and method employing a hyper-directional sound transducer for producing pressure gradients and forces across stationary and moving objects.

Systems and methods for producing a sound pressure field

An improved system for sensing ground motion is provided. The system generally comprises a shell and a case within the shell and connected by a suspension. The mass of the case is greater than the mass of the shell. An electrode within the shell detects relative motion between the shell and the case.

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Winchester, MA, United States of America

James Edwin Barger