Abstract: A real-time data acquisition system for a remote, unmanned underwater vehe includes an array of sensors within the vehicle which gather data from the environment surrounding the vehicle. The sensor data is digitized and stored in an imbedded computer on the unmanned vehicle. To display the data, the imbedded computer transfers the digital data over a local area network connection to a second computer aboard a mother ship. The second computer converts the digital data back to analog data for display. The data can also be analyzed and processed depending on test requirements. To test the unmanned vehicle performance, the vehicle can be operated adjacent the mother ship with the local area network connection in place. In this mode, the imbedded computer transfers the digital data to the second computer as the data is being stored in the imbedded computer.

Abstract: An isolated compensated fluid delivery system is used in an underwater vel, such as a torpedo, to deliver a supply fluid such as fuel, while displacing the supply fluid with a compensating fluid to compensate for change in buoyancy of the underwater vessel. The buoyancy compensated fluid delivery system includes a container, such as a fuel tank, a flexible delivery chamber disposed within the container adjacent a flexible compensation chamber. An outlet is coupled to the flexible delivery chamber and extends outside the container to direct the supply fluid out of the flexible delivery chamber. An inlet is coupled to the flexible compensation chamber and extends outside the container to direct the compensating fluid into the flexible compensation chamber as the supply fluid is being delivered. The volume of compensating fluid is substantially equivalent to the volume of supply fluid such that the weight and displacement of the underwater vessel remains substantially constant.

Abstract: A fluid conduit for flowing electrically conductive fluids includes an elrically conductive pipe, an electrically conductive rod extending axially through the pipe and centrally thereof, a first power source in electrical communication with the pipe and rod, a solenoidal electromagnet disposed around the pipe and a second power source in electrical communication with the electromagnet. Activation of the first and second power sources creates an electric and a magnetic field, respectively, within the pipe which interact and result in a circumferential force in the flow with consequent reduction in wall friction in the pipe.

Abstract: In accordance with the present invention, a method for obtaining frequency nformation about a given data set is realized. The method comprises the steps of providing a processing unit; inputting a raw data set into the processing unit; optionally removing at least one trend from the raw data; ordering the raw data; estimating power spectral density using an eigenanalysis approach and the inputted raw data and the ordered raw data; simultaneously estimating the power spectral density using the raw data and a periodogram; generating a time-series representation of the raw data to which curve fitting is applied; comparing the results from the power spectral density estimating steps and the time-series representation generating step to determine if any frequencies suggested by the eigenanalysis approach estimating step are valid; and generating an output signal representative of each valid frequency.

Abstract: A soft-bodied, towable, active acoustic module includes a specially formed uspension fixture and a flexible faired body enclosing an active acoustic array. The suspension fixture is a Y-shaped tube having a single forward end and two trailing ends, one for attachment of a trailing tow cable and the other for attachment of the flexible, faired body. The flexible, faired body is an elongated hydrofoil having sections which allow lateral bending. The combination of the suspension feature and lateral bending feature allows the module to be deployed and recovered through shipboard undersurface deployment tubes. A weight attached to the faired body near the lower rear end balances the body to maintain a substantially vertical position during towing. Flow steps on the lower portion of the faired body reduce lateral oscillations.

Abstract: A plasma antenna with an acoustic modulator is provided. An ionizer produ a plasma in a horizontal tube to form a bounded plasma column extending along a longitudinal axis. An amplitude-, phase- or frequency-modulated signal is applied to an acoustic transducer that directs an acoustic wave along the longitudinal axis into the plasma. The acoustic wave acts as an ion acoustic wave to oscillate ions parallel to the axis. This movement radiates an amplitude-, phase- or frequency-modulated electromagnetic field from the plasma column.

Abstract: An acoustic sound speed profiling system is provided. The system includes a sound emitter and a series of sensors or hydrophones spaced vertically in a water column. The sound emitter is a high-frequency sound source adap for mounting on the front end of a passive, towed sonar array. The sound source has a frequency which may be outside the acoustic aperture of the towed array. The series of sensors are located at intervals along and embedded within the array tow cable. The sensors are conventional hydrophones or thin-film hydrophone membranes. During operation of the system, the source transmits high frequency sound, which is received by each sensor along the tow cable of the towed array. Calculation of the speed of sound is determined from the position of the tow cable and the time-of-arrival of acoustic signals at each sensor. There is no interference with the normal operation of the passive towed array.

Abstract: A plasma antenna is provided. An ionizer generates an ionizing beam in a nded or unbounded plasma column extending along a vertical axis. An amplitude or frequency modulating signal is applied to an electro-optical crystal that amplitude, phase, or frequency modulates the ionizing beam. The resulting changes in the ionizing beam produce gradients in the plasma that cause ions and electrons to oscillate in a vertical path that generates alternating current having the frequency of the modulator. These currents generate an amplitude- or phase-modulated electromagnetic field that radiates from the plasma column.

Abstract: A protective mounting assembly includes an electrical connector having a erproof body surrounding and protecting a waterproof interface. Components' signal leads are coupled to the interface at a first side thereof. A rigid foundation is rigidly coupled to the connector's waterproof body. A rigid positioning platform is rigidly coupled to the rigid foundation and defines at least one mounting position for the components. The components are positively oriented relative to the mounting positions. An elastomer material encapsulates the rigid foundation, positioning platform, components and a portion of the waterproof body in such a way that the connections at a second side of the connector's interface are accessible from the exterior of the elastomer material.

Abstract: An improved SCSI controller provides a logical connection between a pluray of host processors using a single SCSI initiator. The controller contains removable host adapters for connection to any type of host processor interface. When a host processor requests status information of a target device, that status information is passed to the requesting processor and subsequently stored in the controller and made available to all other host processors. The advantage to such a controller is the expanded number of host processor connections to a single SCSI initiator whereby each host processor can independently and logically connect through the controller and SCSI initiator to a target without clearing target status information for other host processors. The invention is particularly advantageous when adapted to function in a local area network (LAN) arrangement where a significant number of host processors are requesting data from one mass storage device.

Abstract: A method is provided for measuring and recording the relative degree of pical density, congestion, or crowding of objects dispersed in a three-dimensional space. A Population Density Index (PDI.sub.act) is obtained for the actual conditions of the objects within the space as determined from measurements taken of the objects. The PDI.sub.act is compared with values of a PDI.sub.min and a PDI.sub.max, considered as minimum and maximum bounds, respectively, for PDI.sub.act values. The objects within the space are then repositioned to optimize PD.sub.act, thus optimizing the layout of objects within the space.

Abstract: A large panel surface planer is provided. The planer has a flat platform d as a mounting base. A pair of channel rails are clamped to the mounting base using c-clamps at the ends of each channel rail. A workpiece is secured to the flat platform using one or more pairs of back-to-back clamps which clamp both the workpiece and the flat platform. A pair of rectangular guide bars are clamped to and aligned orthogonally with the channel rails using a c-clamp at each end of each guide bar. A tool stop is also clamped at the channel rail-guide bar intersection providing both a tool stop and a spacer for alignment of the spacing between the guide bars. A cutting tool, such as a router, is then manually moved across the surface of the workpiece using the guide bar to hold the tool in position (both height and lateral position). After planing a particular set position, it is necessary to manually reposition the guide bar for the next cut and to continue sequentially until the entire workpiece has been planed.

Abstract: A system and method are disclosed for reducing flow-induced noise in an urwater towed system. The system includes at least one neutrally buoyant towed array, a tow platform for defining a towed direction of the at least one towed array, a neutrally buoyant tow cable connected to the at least one towed array and the tow platform, and a deploy and retrieve apparatus for deploying and retrieving the tow cable. The deploy and retrieve apparatus is connected to both the tow cable and the tow platform. Deployment of the tow cable from the deploy and retrieve apparatus correspondingly deploys the at least one towed array, and retrieval of the tow cable with the deploy and retrieve apparatus correspondingly retrieves the at least one towed array. The speed of deployment of the tow cable can be varied to decrease the velocity of the towed array relative to the surrounding water thus reducing flow-induced noise.

Abstract: A simple and accurate stowage drum and capstan alignment system and method or the Deployable Array Work Group (DAWG) is provided. The system includes a drum reference point fixture for obtaining the drum centerline, a drum sighting assembly and a capstan sight alignment fixture. For each spoke of the drum brought to a predetermined position adjacent the drum reference point fixture, the distance between the bulkhead and the inner and outer flanges of the drum is measured and the centerline position is calculated by averaging the readings. The drum sighting assembly is positioned within the drum and aligned with the calculated centerline. The capstan sight alignment fixture is positioned on the capstan. Looking through the scope of the drum sighting assembly to the capstan sight alignment fixture, measurements are taken of the offset, roll and rotation of the capstan unit relative to the drum. Additionally, a measurement of the drive shaft/flex coupling keyway freeplay is obtained.

Abstract: In accordance with the present invention, a single point lifting device is rovided for a torpedo nose section. The device has two parallel plates, spaced slightly apart with edges placed longitudinally on the nose section. The edges are shaped to fit the nose section contour. A T-shaped member is inverted and fixed between the two plates, each edge of the horizontal leg suitably attached to one of the plates to form an H-shaped section with the vertical leg of the T extending upwards. Two cinch straps extend around the nose section and lifting device to securely hold the plates against the nose section. A metal strap extends between the cinch straps on the opposite side of the nose section from the plates to prevent the cinch straps from slipping off the contoured nose section. To accommodate the varying centers of gravity for different nose component configurations, the lifting hook placement along the T-section can be varied or the T-section can be moved fore and aft between the parallel plates.

Abstract: A countermeasure buoy for use in an underwater environment includes a main ody portion, a propulsion portion, a hull section, and an acoustical array. The main body portion includes a first end and a second end longitudinally opposed from the first end. The propulsion portion includes a main body end connected to the first end of the main body portion and a propelling end opposite the main body end. The hull section includes a rearward end connected to the second end of the main body portion and an open end opposite to the rearward end. The acoustical array is housed within said hull section and includes a base end connected to an interior of the hull section and a free terminal end opposite to the base end. A cap member is removably attached to the open end of said hull section and a vertical alignment of the propulsion portion, the main body portion and the hull portion enables gravitational displacement of the cap member and release of the acoustical array from the hull section.

Abstract: A standing wave plasma antenna is provided. An ionizer generates an ioniz beam in a bounded plasma column extending along a vertical axis. A modulating signal is applied to an electro-optical crystal that modulates the ionizing beam. The resulting changes in the ionizing beam produce gradients in the plasma that cause ions and electrons to oscillate in a vertical path that generates alternating current having the frequency of the modulator. At a remote end the antenna terminates in a reflector. The reflector includes a chamber having a plasma with a charged particle density that is greater than the charged particle density in the plasma. The generated currents are therefore reflected as in a standing wave antenna. These currents generate an amplitude-, phase- or frequency-modulated electromagnetic field that radiates from the plasma column.

Abstract: A sonar sensor array having a multi-layer tiling arrangement for the indiual elements that increases surface area available for each element while maintaining the inter-element spacing required to avoid spatial aliasing when the received signals are combined to form a sonar beam. The array comprises outer and inner arrays of transducer elements for converting an acoustic signal to an electrical response. The transducer elements of the outer array are positioned such than a grid of isolation spaces separates each of the transducer elements. The transducer elements of the inner array are also positioned such that a grid of isolation spaces separates each one of the transducer elements. The electrical response generated by the transducer elements of the inner and outer arrays are coupled to a beamformer which processes the responses to produce an output signal.

Abstract: A method of data fusion determines a best-estimate solution to a moving cact using a plurality of trackers that provide bearing-to-contact data and range-to-contact data. An averaging function is applied to the bearing-to-contact data to determine weighted-average bearing data associated with each tracker. The same averaging function is also applied to the range-to-contact data to determine weighted-average range data. A computed solution to the moving contact is generated using the weighted-average range data and the weighted average bearing data from the one tracker having the lowest standard deviation. A root mean square (RMS) error in terms of bearing is then determined for the computed solution and each of a plurality of independently generated solutions using bearing-to-contact data from the one tracker having the lowest standard deviation. One of the computed solution or the independently generated solutions that produces the lowest RMS error is considered to be the best-estimate solution.

Abstract: A system and survey method for estimating the geodetic position of acoustic sensors placed at fixed but unknown locations on the seafloor is disclosed. Bottom mounted sensors are surveyed using an extension of the well known trilateration survey technique, i.e., making ranging measurements from reference points to the point to be surveyed. For acoustic sensors, these ranging measurements are obtained by transmitting an acoustic signal from a near surface projector and making corresponding timing and/or position measurements, requiring calculation of the Effective Sound Velocity. Bias errors are precluded from propagating to the sensor coordinates by considering timing and sound velocity biases, in addition to the sensor coordinates, as parameters to be estimated.