Abstract: A digital signal processor is disclosed for analyzing sound signals to determine the identification of the sound and the location of the source of the sound, as well as to present its results as an auditory scene. The processing includes producing a gram representative of a sound signal in time, frequency, and space parameters, and then extracting elements from the gram and features from the elements. The elements and the features are routed to an inference engine, which also receives predefined knowledge from a database. The inference engine derives conclusions, which are used to produce the auditory scene.

Abstract: A cable sectional assembly houses an electrically concatenated series of electronic circuit modules and has electric hook-up media interspersed between the modules. Each run of interspersed hook-up media is surrounded by a flexible tubular member, which is oversized to allow movement of the hook-up media without restriction under flexing of the assembly. The assembly is a construction and arrangement of two forms of moldingly bonded encapsulations. The first of these forms is made of a hard encapsulant and forms a unitary encapsulation local to each electronic module which (i) encapsulates the circuit module and associated electrical coupling connections between the adjacent end of each individual run of an adjacent interspersed run of media and an electrical terminal of the module, and (ii) is securely bonded to the adjacent marginal end portions of the tubular members which surround the adjacent interspersed runs of hook-up media.

Abstract: A method for computing three dimensional unsteady flows about an object. An allowable error is established for the vorticity term calculations, and object geometry is provided giving surface points on an object and a region of interest. A mesh is established incorporating points on the object. Initial flow conditions are set at the surface. Vorticity values that will satisfy boundary conditions are set at the provided surface points. A new mesh is established incorporating the provided points and other points in the region of interest. Boxes are generated containing the provided points and other points. Velocities and pressures at each point are calculated from the flow conditions, vorticity values and boundary conditions., A time variable is incremented and each point is moved by applying the calculated velocity. Vorticity at each point is then recalculated. The method is iterated starting with the step of satisfying boundary conditions until the incremented time variable exceeds a predetermined value.

Abstract: A towed airborne array system has a balloon that supports appropriate instrumentation packages overhead and is tethered to a towing ship to improve line-of-sight sensing and communication capabilities to up to about 100 nautical miles. These improved capabilities can benefit relatively small surface combatant ships (CG, DD, FFG) and might provide an alternative location for having countermeasures placed on a warship.

Abstract: The insertion tool is used to insert an oversized O-ring into a groove, such as a internal groove in an seal housing. The insertion tool includes a base for supporting the housing and an O-ring support extending into the housing and having a top support surface generally aligned with the groove. The O-ring is generally held into position proximate the groove using holding pins around which the O-ring is looped. Pie shaped segments are positioned onto the O-ring support between the holding pins to secure respective sections of the O-ring into the groove. Radial pushers are positioned in spaces between each of the segments, and a retainer ring is disposed over the segments and radial pushers. A central pusher rod extends through a hole in the O-ring support and base, and a cam plunger engages cam surfaces on the radial pushers. The holding pins are removed and movement of the cam plunger causes the radial pushers to move radially, thereby completely inserting the O-ring into the groove.

Abstract: The present invention is directed to a method and system for significantly reducing the acoustic noise from near-surface sources using an array processing technique that utilizes Multiple Signal Classification (MUSIC) beamforming and the Lloyd's Mirror interference pattern at very low frequencies. Noise from nearby near-surface sources, such as merchant ships, super tankers, fishing trawlers, seismic profiling platforms, or other sources near the ocean surface can significantly interfere with the detection and tracking of a quiet target-of-interest (TOI) located well below the ocean surface. The present invention reduces the noise of the near-surface sources without degrading the signal level and quality of the TOI. The present invention utilizes a unique application of the MUSIC beamforming process to separate the noise and signal subspace. Next, eigenvalue beamforming is used to reduce narrowband energy in selected frequency bins wherein the near-surface noise is radiating.

Abstract: A system is provided for testing a propulsor having a first end that can attach to a payload and a second end at which thrust is generated. A bulkhead is sealed to the first end of the propulsor. The bulkhead with the propulsor coupled thereto is suspended vertically by a support that is placed in tension when thrust is generated at the second end of the propulsor. A load cell coupled to the support measures tension therein as a measure of thrust.

Abstract: A processing system and method is used to process acoustic and non-acoustic test data acquired from a number of data collectors. The post-processing system and method is implemented as software and hardware capable of running on a PC. The processing system interfaces with a data acquisition (DAQ) system that acquires calibration signals and test data from the data collectors at a test facility. The processing system uses the calibration signals to determine calibration factors representing the relationship between the test data and the appropriate engineering units. The processing system processes the acoustic and non-acoustic test data, applies the appropriate calibrations factors, and plots the acoustic and non-acoustic test data as a function of time to generate run-time plots. Data values are stored and plotted against calculated baseline curves to generate envelope or baseline plots of the collected data.

Abstract: The present invention relates to an improved steering system for a water craft and an improved method of steering. The steering system includes at least two variable camber plates or rudders mounted to a hull of the water craft for imparting a steering force to the water craft. Each of the variable camber plates is preferably formed from a flexible material and has a leading edge affixed to the hull. A linkage mechanism is attached to a steering device on the water craft and causes at least one of the plates to move relative to the hull and thereby vary the camber of the at least one plate.

Abstract: A portable data acquisition system for use in certifying torpedo tube-launched weapons such as a Mark 48/ADCAP, a Tomahawk missile or a Harpoon and the like. The system includes a portable computer, a rugged four slot chassis, a 32 channel multiplexing module, a four channel isolation amplifier with excitation, eight channel isolation amplifier, a custom signal conditioning module, an associated terminal block and interface cables. The system has the unique feature of obtaining live data for quick analysis about the launched weapon using the torpedo tube as opposed to the post launch data for analysis. All the components are housed in a shock resilient and weather-tight container.

Abstract: A nonlinear signal processing system and method is used to identify nonlinearity (e.g., chaos) in underwater acoustic signals, such as sonar signals. The system and method detects the underwater acoustic signal and digitizes the underwater acoustic signal to produce an acoustic time series. The acoustic time series is reconstructed using a phase space embedding algorithm to generate a phase space embedded acoustic signal. A differential radius signal is generated from the phase space embedded acoustic signal using chaotic radius computations and differential radius computations. Thresholds can be detected in the differential radius signal to reveal nonlinear or chaotic events hidden in the underwater acoustic signal.

Abstract: A system is provided in which a torpedo is launched from a submarine and pays out an optical fiber as it moves away from the submarine towards a target. The optical fiber is attached to the submarine and provides an optical communications link between the submarine and the torpedo. In addition to carrying communications between the submarine and torpedo, the optical fiber includes optical acoustic sensors. The optical fiber serves as a forward deployed acoustic array to gather target bearing and range data that is processed at the submarine. With the array deployed directly within the engagement arena, the submarine can more accurately analyze the acoustic environment to better guide the torpedo through countermeasure avoidance and to target acquisition. The optical fiber pays out behind the torpedo at the same rate that the torpedo moves away from the submarine.

Abstract: A two way pressure relief valve for equalizing pressure between a first region and a second region. The valve has a housing with a lateral aperture in communication with the second region and a first aperture in communication between the first region and the lateral aperture. A piston assembly having an annular rim portion is retained slidably within the housing. Flutes are formed in the piston assembly for allowing fluid communication between the first region and the second region. An annular retaining piece having a second aperture therein is joined within the lateral aperture in the housing at the second region for retaining the piston assembly within the housing. A first biasing means is positioned in the housing between the first aperture and the piston assembly for biasing the piston assembly away from the first aperture. A second biasing means is positioned in the housing between the retaining piece and the piston for biasing the piston assembly away from the second region.

Abstract: The present invention having enhanced maneuverability that has hull at least partially submerged in fluid, which will ordinarily be water. The vehicle has a forward bow, a longitudinal axis extending rearwardly from said bow and opposed first and second sides. The first and second sides have respectively a first major opening and a first small opening and a second opening. A fluid-conducting tunnel extends generally transversely through the hull from the first major opening on the first side of the hull to the second major opening on the said side of the hull. There is a propeller for causing fluid to flow through the tunnel. In order to compensate for the detrimental effect on thrust (T) caused by increases in forward vehicle velocity (Vv), angular speed (N) of the propeller is increased proportionally to measured increases in axial fluid velocity (Vx).

Abstract: A quadrifilar helix antenna is provided having a feedpoint for the antenna connecting to individual helical antenna elements. Each antenna element comprises a normal helix element with a plurality of series capacitors inserted along the element length with a maximum capacitor value at a feed end and a minimum capacitor value at a remote or unfed end. Again, the element is not simply a series of connected capacitors-if it were it would not radiate. The element is a normal element, which is inductive, which has had capacitors inserted along its length.

Abstract: A joint band assembly secures payload and drive sections of a torpedo together and subsequently separates them while the torpedo is making a run. A pair of essentially semicircular bands is arranged in a ring shape have radially inwardly extending lip portions that compressively engage circumferential rims radially outwardly extending from a separation section having first and second parts connected to the payload and drive sections. Adjacent ends of the semicircular bands are coupled together by electro-explosive devices (EEDs) that each has a tubular body portion containing an explosive charge adjacent an annular segment of the tubular body portion. The annular segment has reduced thickness as compared to thickness of the tubular body portion to assure its rupture and separation of the body portion and the interconnected bands.

Abstract: An encapsulation assembly includes a housing having a nose end, a tail end, and a body portion between the nose end and the tail end. A plurality of acoustic transducers are positioned within the body portion of the housing, each of the plurality of acoustic transducers having a wiring connection attached thereto. A tow cable is connected to the nose end of the housing and is in communication with the wiring connection from each of the plurality of acoustic transducers. A characteristic of the assembly is that at least the body portion of the housing is entirely formed of a solid casting of plastic material thereby environmentally isolating the plurality of acoustic transducers within the body portion of the housing. This configuration prevents water intrusion into the transducer elements, and increases the cavitation threshold for the acoustic array, thereby allowing the array to be driven to higher acoustic intensities.

Abstract: A remote acoustic detection system includes at least one detection unit delivered to a remote or inaccessible location by a missile or other aircraft. The detection unit monitors acoustic events at the location such as aircraft takeoffs and landings and preferably is provided the capability of classifying the events, for example, as to the event or type of aircraft. A sleep mode can be provided to conserve power such that the unit is activated only in the presence of threshold acoustic levels. The unit also includes a wireless transceiver for relaying data to a central monitoring authority, which may be a passing or loitering aircraft. Each detection unit may be provided with an address for allowing monitoring of a network of detection units.

Abstract: An electrical connector assembly including a female connector assembly and a male connector assembly configured for quick push-pull connect and for squeeze-to-release disconnect. The female and male connector assemblies are each molded of a plastics material.

Abstract: The non-command, visual interaction system provided for a shipboard watchstation has three major subsystems, an operator-locating subsystem, a visual capture subsystem, and a computer-operated watchstation. The operator-locating subsystem uses an overhead infrared tracker with location tracking hardware to identify operator presence and operator head location. An eye-tracking camera, with eye-tracking hardware monitors the watch operators visual scan, gaze location and dwell time, blink rate and pupil size. An algorithm determines when additional cueing of the operator should be made based on eye-monitoring parameters.