Abstract: The present invention provides a method and apparatus for enhancing active sonar signal detection by estimating the channel/target response utilizing measured values of the excitation signals and received signals. A Wiener/Volterra series expansion for the excitation and received signals is used as a model, wherein a time invariant environment is assumed, thereby disregarding all random noise contributions. The Wiener/Volterra kernels are then determined in a nonlinear processor using a method of correlations which is designed to produce the kernels utilizing only measured white Gaussian excitation signals and received signals. The kernels can be used to give an optimum correlation between the excitation signals and the received signals.

Abstract: A distributed fiber strength member tow cable termination assembly (DTCTA) having a strength member termination area which is spaced from a signal conductor termination area, and which includes a seal area having a plurality of sealing members is disclosed. The strength member termination area preferably includes a strength member termination wedge having a curved outer face which allows for higher termination efficiency. The strength member termination area and signal conductor termination area are distributed, or separated, a predetermined distance by an interface section, for example a length of hose. The separation of the strength member termination area from the signal conductor termination area allows for several improvements in the DTCTA not possible in the prior art due to the previous need to terminate the signal conductors co-located with the strength termination member.

Abstract: Non-chromate solutions for treating and/or etching metals, particularly, aluminum, aluminum alloys, steel and titanium, and method of applying same wherein the solutions include either a titanate or titanium dioxide as a “drop-in replacement” for a chromium-containing compound in a metal surface etching solution that otherwise would contain chromium.

Abstract: A parametric sonar for use in a liquid medium includes a first signal generator which transmits a first acoustic signal and a second signal generator transmitting a second acoustic signal which interatct to produce a difference frequency signal at an interference region. A cavitation generator is provided to transmit a cavitation acoustic wave causing cavitation vapor bubbles in the liquid medium at the interference region. The cavitation vapor bubbles improve the efficiency of generating the difference frequency signal.

Abstract: An apparatus for launching an object in a fluid environment having a tubular member with a forward muzzle end, an opposed rearward end. The object is positioned in the tubular member. Ends of the tubular member are closed by expellable members. Flood valves are located on the expellable members and, on activation, allow flooding of the tubular member by external fluid. A propellant device and an object contact member are disposed within the tubular member. When the propellant device is activated, the object contact member moves the object. These actions are controlled by a control device which first causes the flood valves to enable fluid to flood the interior region. Next, the control device causes the expellable members to be expelled from the tubular member. The control device then causes the propellant device to generate gas in a predetermined manner launching the object from the tubular member.

Abstract: A circuit interrupter device protects a load circuit from excessive, or overloading levels of current, provides a visual indication of circuit overload and open circuit, and can be reset. A multi-metallic heat reactive strip is snapped by an overload current to open the load circuit and close a light emitter circuit having a current limiting resistor connected to an indicator lamp that provides a visual indication of the open circuit. The multi-metallic strip is manually reset via a push button to open the light emitter circuit and extinguish the indicator lamp and close the load circuit to reestablish operation therein. The circuit interruption device can be made utilizing currently available technology for miniature fusing in tight, confining spaces and/or assemblies that have unusual shapes that restrict access in automobile electrical systems, test instruments, domestic appliances or many other electronic/electrical circuits.

Abstract: An assembly is provided for retaining standard electrical plugs within receptacles in environments having vibration and shock conditions that loosen normal electrical plugs. The present invention includes an adapter with a first locking mechanism for locking the adapter to the electrical receptacle. The adapter contains a standard electrical receptacle to receive the power plug prongs of the power plug. In a preferred embodiment, a restraining collar is mounted adjacent the power plug and secured to the adapter with tie straps to thereby secure the power plug to the adapter.

Abstract: An underwater acoustic receiver sensor is disclosed that measure up to seven (7) quantities of acoustic field at a collocated point. The quantities measured by the acoustic receiver sensor are acoustic pressure, three orthogonal components of acoustic particle acceleration and three spatial gradients of the acceleration vector. These quantities are appropriately combined and provides for improved directivity of the acoustic receiver sensor.

Abstract: An acoustic array deployment system and a method are provided. An optical fiber acoustic array has a first end coupled to a projectile housed onboard an underwater vehicle. A second end of the array is coupled to the underwater vehicle. The acoustic array is stored on a spool while the projectile is housed onboard the underwater vehicle. The projectile is launched from onboard the underwater vehicle in a gravitationally downward direction that is not aligned with the underwater vehicle's direction of travel. As a result, the acoustic array is paid out from the spool as the projectile is launched and then sinks. By establishing the line array's broadside beam in a direction that is away from the vehicle and approximately perpendicular to the vehicle's direction of travel, the relative angular difference between the underwater vehicle and target can be used to guide the vehicle towards the target.

Abstract: A hydraulically activated device for spacing plural towed lines includes a toroidal and inflatable tube member defining an aperture in an opening of the toroid shape. A plurality of connectors each secure a corresponding one of the plural towed lines to the toroidal and inflatable tube member. The toroidal and inflatable tube member is inflated with sea water to a predetermined volumetric configuration suitable to an operating speed range of the towed lines and upon inflation will space the towed lines in a three-dimensional arrangement therearound. A sheath may also be formed around the toroidal and inflatable tube member, the sheath being formed in cross section as a tear drop or similar streamlined shape.

Abstract: A multimode invariant processor is provided to simultaneously classify one or more patterns in multidimensional or in two dimensional “real world” images. The classification is invariant to a translation, a change in scale size and a rotation of a whole or partially hidden photonic image. The multimode invariant image processor comprises a retina portion, a nonlinear processing portion, a convergence processing portion and a classifier portion. The retina portion processes the photonic image to obtain an image data array of pixels and further process the array of pixels through a window difference network to obtain gradients of the image data. The neural directors of the nonlinear processing portion receive the gradients and generate respective feature vectors, which may have a greater dimensionality than the gradient information, to aid in discrimination between similar patterns in the image data.

Abstract: A system and method provides automatic monitoring of data representing the onset of, or occurrence of fault conditions for a submarine mast system. The system is separately programmable and transparently operable with respect to the mast host system that controls mast functions. In a preferred embodiment, a plurality of sensors are in communication with a microprocessor system to record data by time and date of the event. The communication of data from the sensors to the microprocessor is electrically isolated from control signal communications to mast components, and the sensors are further individually opto-isolated. The microprocessor may selectively transfer data on a time-shared basis over host system communication lines to an independent memory collecting submarine fleet data, as an aid in fleet-wide maintenance decision making.

Abstract: A method for maximizing the radiated power of a transducer, such as a sonar transducer, includes providing a transducer system comprising a transducer operating at a frequency f and having a radiating face, a tuning fluid having a density &rgr;1 and a speed of sound c1, a tuning plate having a density &rgr;p and a thickness t, and an external fluid having a density &rgr;2 and a speed of sound c2; and tuning the transducer to have a maximum specific acoustic resistance at the radiating face in accordance with the equation: [ ( 2 ⁢   ⁢ π ⁢   ⁢ f ⁢   ⁢ ρ p

Abstract: A supercavitation ventilation control system is disclosed and includes a vehicle body having a fore end and an aft end. A cavitator is fit to the fore end of the vehicle body, the cavitator generating a gas cavity around the vehicle body. A cavity control ring is slidably positioned at the aft end of the vehicle body, the cavity control ring selectively adjusting a terminal end of the cavity formed by the cavitator. A stop ring is adjustably positioned on the vehicle body forward of the cavity control ring for managing a reentrant jet generated by the cavity control ring. Each of the stop ring and cavity control ring are moveable by separate actuators and a single control system.

Abstract: A compact antenna transmits and receives broadband electromagnetic energy signals over a 180° hemispherical pattern in air at the ocean's surface. The antenna has an elongate semi-cylindrical shell and a circular end disc connected to one end, and a semi-circular end disc connected to the other end to form a half-cylinder cavity. A curved plate is connected to the circular end disc and a curved body portion has a curved end extending parallel with the semi-cylindrical shell. A vertical stem has an upper portion connected to the curved plate. The semi-cylindrical shell, circular end disc, semi-circular end disc, and vertical stem are made from a material that is conductive of electromagnetic signals, and they can be differently dimensioned to change the center frequencies to embrace different broadband ranges. The antenna is deployed and retrieved from a submarine in a tow body.

Abstract: A method and apparatus for analyzing newly acquired and faded or lost sonar contacts. Initial processing identifies a list of possible associations between a newly acquired contact and lost contacts. Subsequent processing of the possible associations reduces the number of possible associations that a sonar operator must consider in determining whether an acquired contact represents a new contact, a reacquired lost or faded contact.

Abstract: An information processor is installed onboard a seagoing vessel that has at least one onboard system, e.g., a weapon system, to carry out a mission that is defined by instructions originating at a remote location, e.g., mission data updates (MDU) data. The information processor is programmed to receive unencrypted data related to the mission. A secure communications terminal has a first hardwire connection to a public switched telephone network (PSTN) and a second hardwire connection to the information processor. The secure communications terminal receives encrypted data related to the mission over the first hardwire connection, converts the encrypted data to unencrypted data and supplies the unencrypted data over the second hardwire connection.

Abstract: The present invention relates to a system for collecting ocean turbulence data without interference from the hydrodynamic effects of the vehicle. The ocean turbulence data collection system comprises an underwater vehicle, such as an unmanned underwater vehicle, at least one sensor for collecting the ocean turbulence data, and a stinger arrangement mounted to the nose portion of the vehicle for positioning the at least one sensor sufficiently forward of the nose portion of the vehicle to avoid interference from the hydrodynamic effects of the vehicle. The collection system is also provided with at least one accelerometer for compensating for motion not induced by turbulence.

Abstract: A launch assembly having an elastomeric tube for launching a device is disclosed. To launch the device an outboard end of the tube is movable outwardly along the length of a housing by an extending device, while the inboard end of the tube is restrained by a release mechanism and remains stationary. Thus, as the outboard end moves and the inboard end remains stationary, the elastomeric tube elongates. The tube may be elongated a predetermined amount, at which time the inboard end of the tube is released by the release mechanism. Releasing the inboard end allows it to travel toward the now stationary outboard end with a sufficient velocity to launch the device. The amount of elongation of the tube is related to the amount of possible launch energy. Thus, greater elongation of the tube provides a greater launch velocity, while shorter elongation provides a reduced launch velocity, as desired.

Abstract: A portable flood control revetment comprising an elongated collapsible and inflatable tube of flexible material impervious to air and water, the tube having a bottom wall and other walls defining an internal compartment, and a multiplicity of cables in the compartment, each extending from one of the walls to another of the walls to hold the tube in a selected shape when the tube is filled with air or water. The bottom wall defines at least one pocket for receiving a corresponding at least one hold-down member, and other of the walls are provided with closeable orifices for permitting flow of air and water into and out of the compartment to respectively inflate, fill, and collapse the tube.