Abstract: A compact floating seal system for sealing a rotating shaft within a structure. The floating seal system has a cylindrical outer seal housing positioned within the structure with a cylindrical internal recessed region formed in the outer seal housing and a retaining flange extending into the internal recessed region. An axial retaining means axially retains the outer seal housing against the structure, and an outer torque member prevents rotation of the outer seal housing with respect to the structure. An inner seal housing is retained within the internal recessed region and abuts the retaining flange for preventing axial movement of the housing. The inner seal housing has a shaft aperture therethrough. First and second sealing member retaining grooves formed within the shaft aperture retain O-rings. A lubricant recess is formed within the shaft aperture between the grooves.

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 method for finding a probability density function (PDF) and its statistical moments for a chosen one of four newly derived probability models for an arbitrary exponential function of the forms g(x)=&agr;xme−&bgr;xn, −∞<x<∞; g ⁡ ( x ) = α ⁢   ⁢ x m ⁢ ⅇ - βx n , 0 ≤ x < ∞ ; g ⁢ ( x ) = α ⁡

Abstract: A method is disclosed for evaluating and/or selecting sonar systems and sonar sensors is provided that results in a performance rating that represents both the magnitude and consistency of detection of targets positioned at different depths. In a preferred embodiment wherein a sonar system includes at least one source and at least one receiver, the performance rating related to target detection, is plotted for each of a plurality of source and receiver depths. A dynamic range sensitivity factor is selected that provides sensitivity in the performance rating with respect to consistency of the detection range at different depths. The dynamic range sensitivity factor is preferably selected between zero and an inverse of a scaling factor related to a maximum detection range and a minimum detection range for a particular source and receiver depth relationship.

Abstract: A Submarine Horizontal Launch TACTOM Capsule (SHLTC) provides the capability for launching a Tactical Tomahawk (TACTOM) cruise missile from a horizontal torpedo tube on a submarine. The SHLTC completely encapsulates the TACTOM missile in the torpedo tube and is ejected from the torpedo tube with the TACTOM missile during launch. The SHLTC contains the TACTOM missile in a closure assembly to protect the TACTOM missile from damage. Following safe exit from the submarine, thrust from the rocket motor allows the TACTOM missile to break through a forward tearing shell of the SHLTC. The TACTOM missile and SHLTC completely de-couple and the SHLTC safely sinks away from the submarine and missile. The TACTOM missile continues up to broach the surface and transition to cruise mode.

Abstract: A muzzle door latch, or attachment mechanism, incorporates spring-loaded plungers acting within concave surfaces to provide additional resistance to vibration. The door, or cap, has an elastomeric seal about its outer circumference, which fits snugly within the muzzle. Diametrically opposed guides are attached to the outer side of the cap and extend radially past the outer edge of the muzzle. A plate is attached to the exterior of the muzzle, corresponding to each guide, and each plate extends slightly beyond the end of the muzzle. A roller on each guide engages the outer surface of the plate when the cap is positioned within the muzzle. The plates have a concave indentation on their inner surface, and a spring-loaded plunger on each guide is biased against the concave surface.

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 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: 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: 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 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: 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: 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 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: 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 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 vehicle launch assembly for underwater platforms includes a water tank mounted on the platform, and a plunger movably disposed in the tank and dividing the tank into first and second zones, the first zone being in communication with a. water environment in which the platform is disposed, and the second zone being in communication with a launch tube inlet line mounted on the platform. An actuator is connected to the plunger and is operable to move the plunger in the tank. A triggering device initiates operation of the actuator, moving the plunger in the tank to push water from the tank second zone to the launch tube inlet line to eject a vehicle from the launch tube, or moving the plunger to enlarge the tank second zone to draw water thereinto from a valve in communication with the water environment and the tank.