Abstract: A portable, diver-operated cryogenic freezing unit cleans surfaces underwater. A housing has a first chamber that contains cryogenic liquid, such as liquid nitrogen, and a second chamber is disposed adjacent to an end portion that fits about contaminating matter on a surface underwater. A valve vents cryogenic liquid from the first chamber to expand as gas in the second chamber. The vented cryogenic liquid and gas freeze a slug of water and the contaminating matter on the surface within the end portion. The housing is bent, twisted or otherwise displaced to break or pry-away and remove the frozen slug of water and contaminating matter from the surface to thereby clean it. A method of cleaning a surface underwater using the cryogenic freezing unit is described.

Abstract: A method of controlling the lateral position of a towed body in water where the body is equipped with effectors for effecting at least aileron and rudder control. A lateral correction is defined by a distance measured perpendicular to the towed body's direction of travel. A first command indicative of an aileron control is determined that would cause the effectors to move the body laterally of the direction of travel by an amount equal to the lateral correction. A second command indicative of a rudder control is determined that would cause the effectors to move the body laterally of the direction of travel by an amount equal to the lateral correction. The first and second commands are combined to define a combined command that is applied to the effectors so that the optimum aileron and rudder controls are implemented simultaneously.

Abstract: A portable, diver-operated cryogenic freezing unit cleans surfaces underwater. A housing has a first chamber that contains cryogenic liquid, such as liquid nitrogen, and a second chamber is disposed adjacent to an end portion that fits about contaminating matter on a surface underwater. A valve vents cryogenic liquid from the first chamber to expand as gas in the second chamber. The vented cryogenic liquid and gas freeze a slug of water and the contaminating matter on the surface within the end portion. The housing is bent, twisted or otherwise displaced to break or pry-away and remove the frozen slug of water and contaminating matter from the surface to thereby clean it. A method of cleaning a surface underwater using the cryogenic freezing unit is described.

Abstract: A catalytic heater supplies heated water that circulates to heat a diver's suit. An insulating housing closed at opposite ends by cap members defines a chamber containing a catalyst inside of a multi-tube heat exchanger. Fittings in the cap members pass water through the multi-tube heat exchanger to and from the suit, and a gas circuit flows mixed hydrogen and oxygen to the catalyst that reacts with the mixed hydrogen and oxygen to produce heat that heats the water in the multi-tube heat exchanger for the diving suit. Optionally, hydrogen may be mixed with oxygen from a breathing gas mixture so that after heating the water, the gases remaining may be breathed by the diver. The catalytic heater provides a safe, reliable source of warm water for active thermal protection of divers over a wide range of diving applications.

Abstract: A method is provided for determining multiple feature variances in a medium. Acoustic sources are positioned on one side of a selected scattering direction. Acoustic receivers are positioned on an opposite side of the selected scattering direction such that, for each acoustic source, there is a corresponding acoustic receiver located at a mirror-imaged position relative to the selected scattering direction, and such that a Bragg scattering wave vector associated with each acoustic source/receiver pair is parallel to the selected scattering direction. Each acoustic source is operated at a unique time to direct a broadband ultrasonic pulse at the region of interest. An acoustic scattered wave reflects from the region of interest and is detected as a waveform at the pair's acoustic receiver. Each waveform is converted to the frequency domain to form a spectral waveform. A band of Bragg wave numbers is determined for each spectral waveform.

Abstract: A dive mask display system integrates a plurality of components in the mask's frame. These components can include: a radio frequency (RF) antenna for receiving RF signals indicative of dive information, a display that is directly viewable in a peripheral vision area of the diver but outside of the field of view defined by the mask's lens(es), a diver-controlled controller, and a depth sensor. The various monitored information, as well as bottom time tracked by the controller, can be displayed simultaneously.

Abstract: A wideband-to-narrowband conversion method and apparatus performs the operational step of receiving an acoustic wideband signal, initially incident on an array of acoustic wideband transducers and subsequently digitized, and in response thereto generating a spatial Wigner bilinear kernel output signal, and the operational step of receiving and spatially bandpass filtering the spatial Wigner bilinear kernel output signal to remove a wideband low frequency portion as well as any unwanted noise therefrom and retain and output only a narrowband portion thereof.

Abstract: An interface system supports a load from a surface. A disc-shaped base member is adapted to be secured to a supporting surface. A flexible member has one portion secured to the base member and another portion extends from the base member in a flexible loop to attach and support a tensile load. A cavity in the base member faces an inner surface thereof and contains an adhesive to secure the one portion of the flexible member, and an opening in the center of the base member extends from the cavity to the outer surface to pass the load-bearing flexible loop from the center of the base member and provide a flexible attachment for the tensile load in the center of the base member.

Abstract: A tool is provided for facilitating angular alignment of a hydrofoil coupled to a mounting block having a flat bottom surface area. The mounting block is pivotally coupled to a cylindrical strut having a longitudinal axis. The tool has a saddle for engaging the cylindrical strut and a plate coupled to the saddle. The plate has an alignment edge that, when positioned by the saddle beneath the flat bottom surface area of the mounting block, forms a desired angle with respect to the longitudinal axis of the cylindrical strut.

Abstract: Digital image data is manipulated for improved image visualization and analysis. A two-dimensional image includes relevant subject matter and a substantially homogeneous background that at least partially borders on the relevant subject matter. A first sub-image is defined from the two-dimensional image that includes the relevant subject matter and a reduced amount of the substantially homogeneous background. A second sub-image is defined from the first sub-image that substantially defines just the relevant subject matter. A plurality of image processing options are selected from a library of image processing options. The second sub-image is then processed in accordance with the image processing options to generate image output data. The image output data can be displayed for viewing and/or analysis.

Abstract: A system and method are provided for improving vehicle safety in a crash situation for a vehicle having mountable vehicle components. A plurality of pyrotechnic bolts are used to mechanically couple at least a portion of the vehicle components to the vehicle. A force measuring device measures forces experienced by the vehicle during a crash and produces a signal indicative thereof. This signal is compared with a threshold. An activation signal is generated when the threshold is attained. Failure of the pyrotechnic bolts is then initiated in accordance with a prescribed plan.

Abstract: A detonation arrestor cuts the detonating cord of a dud line charge to prevent the pressure wave from a nearby explosion from sympathetically detonating the dud line charge. A housing of the detonation arrestor has a transverse passageway to receive the detonating cord of the dud line charge and an axial bore intersecting the passageway. A cutter piston having a cutter blade is disposed in the bore and is sized to permit axial displacement by a shallow dish-shaped diaphragm spring. The diaphragm spring has its center adjacent to one end of the cutter piston and laterally extends from the bore to be secured to the housing along its round periphery in a sealed relationship. The diaphragm spring is formed in the configuration of a Belleville spring from a spring material providing strength, rigidity, and spring modulus to snap to an extended position when displaced to a position past an over center position by an impinging pressure wave.

Abstract: A self-contained, self-surveying differential GPS base station system and method of operating same are provided. The system and method use a conventional differential GPS base station. The base station's National Marine Electronics Association (NMEA) data sentences identify a determined position of the base station and fix quality information associated with the determined position. The system and method automatically identify the determined position as an acceptable position when the fix quality information associated with the determined position satisfies a selected criteria which is stored on-site. The system and method then automatically average together each acceptable position to generate an updated position. The updated position is automatically supplied to the base station at a prescribed time for use by the base station in generating Radio Technical Commission for Maritime Services (RTCM) differential corrections for transmission over the air waves.

Abstract: An image processing method improves contrast of relevant subject matter surrounded or partially bordered by a substantially homogeneous background. A first sub-image is defined that includes the relevant subject matter and a reduced amount of the substantially homogeneous background. A second sub-image is defined from the first sub-image that is substantially just the relevant subject matter. If any of the homogeneous background remains, a smoothing routine can be applied to the edges of the second sub-image. The second sub-image can then be re-scaled to a given dynamic range for improved contrast of the relevant subject matter.

Abstract: An aqueous foam generating system and method are provided. A first solution has particles of a carbomer resin encapsulated within an anhydrous, non-polar, organic hydrophobic surfactant. A second solution, capable of ionizing the carbomer resin, is pumped into an eductor which draws a volumetric portion of the first solution to form a mixture that is sprayed from an aerator to form an aqueous foam having long wet-to-dry transition times.

Abstract: An underwater high energy acoustic communications device has inner shell-like structure having an outer surface connected to first ends of tuning springs and outer shell-like structure having an inner surface connected to second ends of the tuning springs to concentrically locate and space the inner and outer structures apart. Explosive units mounted on the inner surface of the outer structure each includes an explosive squib, rigid tube, and projectile. A micro-controller feeds firing signals over electrical leads to the explosive units to detonate them and fire their projectiles to strike the inner structure that emits ringing high-energy broadband acoustic signals that are propagated into surrounding seawater. A transducer connected to the micro controller receives acoustic signals from a remote source to activate the micro-controller to generates preprogrammed sequences of firing signals to propagate coded messages by the high-energy broadband, acoustic signals.

Abstract: An airborne remote piloted vehicle does not require onboard fuel to greatly extend its endurance and payload capability. Photovoltaic cells are provided on substantially the entire bottom surface of the RPV to receive high intensity radiation beamed up from a ground station. The photovoltaic cells can be made responsive to visible light, infrared light and/or ultraviolet light emitted from lasers that direct narrow, high energy beams, or other directable narrow beams of other wavelengths of high energy radiation, including but not limited to microwaves. The cells convert the beamed up radiation to power at least one electrical motor driven propeller and instrumentation for onboard components including sensors, lasers, radio transmitters, and associated instrumentations. Control signals may also be beamed up or otherwise transmitted to the vehicle to control its transport to and hovering at an on-station location and to activate the onboard components for reconnaissance, monitoring, and relaying data.

Abstract: A reconnaissance/surveillance system for remote viewing of a selected location while providing a standoff distance from the selected location for personnel controlling the reconnaissance/surveillance system includes a remote controlled underwater vehicle and a delivery vehicle formed to deliver the remote controlled underwater vehicle to an underwater deployment position. An operator control console in the delivery vehicle is connected to the remote controlled underwater vehicle via a fiber optic communications link. A battery powered propulsion apparatus moves the remote controlled underwater vehicle through water to a viewing station under control of the operator control console. The remote controlled underwater vehicle includes sensing apparatus that provides signals that the operator control console uses to navigate the remote controlled underwater vehicle to the viewing station.

Abstract: A method transforms non-speech input signals into the temporal, spectral and redundancy patterns resembling that of human speech.

Abstract: An active magnetic anomaly sensing system includes a transmitter for transmitting a magnetic field towards a target. The magnetic field induces magnetic moments in the target which cause a magnetic anomaly field to propagate from the target. A first sensor positioned a distance D from the target directly senses magnetic field strength and produces a first output. A second sensor positioned a distance (D+d) from the target directly senses magnetic field strength and produces a second output. A controllable power supply is coupled to the transmitter for selectively activating and deactivating the transmitter. The first and second outputs are produced when the transmitter is deactivated. The second output is subtracted from the first output to generate a differential output indicative of the magnetic anomaly field propagating from the target.