Abstract: An amplitude, phase and frequency modulator circuit is provided with the circuit containing a periodically driven switch. The circuit connects a DC power source and a resistive load. Periodic operation of the switch generates a square-wave of voltage across the load. A transistor used as a switch is embedded in a switch driver that controls base current and base-emitter reverse bias voltage. The modulator DC input resistance is approximately equal to the load resistance when the switch ON-state period and OFF-state period are approximately equal. The modulator efficiency is nearly one hundred percent. The frequency response of the square-wave modulator system is high-pass with a lower cutoff frequency determined by element values.

Abstract: A method for localizing the range and bearing of a distant underwater object includes firing a preselected number of supercavitating projectiles sequentially from a firing location such that each projectile tracks along substantially the same trajectory. Supercavitating pellets are dispersed from a projectile at a pre-selected range. Acoustic signals are sensed to detect acoustic signals caused by supercavitating pellet impact with an object. These signals can be processed to determine the range and bearing to the object. In further steps the range and bearing can be used to aim the projectiles.

Abstract: Systems and methods for automatically applying fairings to a cable as the cable is deployed from a winch are provided. Each fairing has two halves, with each half having a recess, or groove, to accommodate the cable. Like halves are connected together and the two halves are stored on separate spools. Counter-rotating wheels adjacent to and on opposite sides of the cable serve to feed the fairing halves from the spools to the cable as the cable is deployed. As the fairing halves approach the cable, magnets in the fairing halves are attract each other and bring the two halves together around the cable and firmly hold the two halves together. When the cable is retrieved, guides align the fairings such that a wedge can pry the two halves apart. The halves can be picked up by the wheels and fed back onto the spools.

Abstract: A synthetic muscle comprises an outer layer having an interior filled with a proton containing electrolyte. A first electrode extends into the interior, and a second electrode extends through the interior. The second electrode is attached to the outer layer at two locations. An ion selective microporous membrane extends through the interior along the length of the second electrode and is also attached to the out layer at the two locations. The ion selective membrane is also attached to the second electrode at a plurality of points along its length, defining a plurality of pockets of the ion selective membrane. The ion elective membrane is generally disposed between the two electrodes. The two electrodes are in communication through a power source. Using the power source, an electroosmotic flow is established across the ion exchange membrane from the first electrode to the second electrode, inflating the pockets and constricting the outer layer.

Abstract: A handling system with an improved fairlead is provided for protecting a tow cable wherein the cable breaking strength exceeds the system-rated tension load; the fairlead being positioned collinearly between the system bellmouth and winch. A guide slot passes through the fairlead positioning the cable higher than the winch release point and bellmouth entry point, maintaining the cable down-slope as the cable exits the fairlead. The slot has a hemispherical portion tapering inward to a groove extending downward. Near the groove bottom, at the fairlead end nearest the bellmouth, is a cutting device. Under tension, the cable rides in the hemispherical portion of the groove. If tension suddenly increases from a snag, the resulting force drives the cable down into the groove where the cable is cut by the device, separating before the force damages the system. The constrained cable end is securely held in place by the taper.

Abstract: A deployable and inflatable/deflatable fendering apparatus capable of providing protection for watercrafts and docks. The apparatus has an inflatable cylindrical body, an outer collar body, and a water reservoir with an inflating and deflating means. The collar body circumferentially surrounds the cylindrical body, and is made of abrasion resistant materials and protects the cylindrical body from punctures, tearing and abuse. The collar body may be inflatable or filled with foam-like material. The reservoir comprises a one-way valve, a series of ballasts and is attached to the cylindrical body and is expandable to provide stabilization of the fendering apparatus. The fendering apparatus can be deflated for storage.

Abstract: A testing apparatus is disclosed that includes a turntable, an upper scissor jack assembly and a lower scissor jack assembly positioned in parallel planes, about a longitudinal axis and affixed to a base. The apparatus is powered by at least three motors with supporting controllers. The lower assembly is affixed to the base mechanically via the turntable which allows the lower assembly to rotate with respect to the upper assembly. There are two loading plates attached to the hinges of each scissor jack. The test specimen is secured by the loading plate. Each scissor jack operates by a screw-gear powered by one of the motors. Upon energizing a stepper motor; the screw-gear positions a scissor jack to apply a tension or compression on the specimen. While subjected to tension or compression, the lower jack assembly can be rotated with respect to the upper assembly for in-plane shear loading.

Abstract: A system for deploying a fiber optic line sensor is provided that includes a launch vehicle to which three sections are attached. The first section is a buoy antenna section. The second section is an electronics canister section having control electronics. These sections are releasably attached to the launch vehicle. The electronics canister section is in contact with the antenna section and secured to the antenna section by a spring band. A communications cable is attached between the antenna and the control electronics. The third section is a spool section containing a spool of a fiber optic line sensor. This third section is attached to the launch vehicle by a rigid mount and is in contact with the electronics canister section. The fiber optic line sensor extends from the spool section into the electronics canister section to the control electronics.

Abstract: A method for solving a combinatorial optimization problem and applying the solutions to routing as employed in naval convoying and other transit point scheduling. The method involves isolating a plurality of vertices into open-ended zones with lengthwise boundaries. In each zone, a minimum length Hamiltonian path is found for each combination of boundary vertices, leading to an approximation for the minimum-length Hamiltonian Cycle. The method discloses that when the boundaries create zones with boundary vertices confined to the adjacent zones, the sets of candidate HPs are found by advancing one zone at a time, considering only the vertices in the zone in question (with embedded HPs from previous zones) and an adjacent zone in the direction of progression. Determination of the optimal Hamiltonin paths for subsequent zones has the effect of filtering out non-optimal Hamiltonian paths from earlier zones.

Abstract: Non-linear control laws are disclosed and implemented with a controller and control system for maneuvering an underwater vehicle. The control laws change the phase of one Inferior-Olive (IO) neuron with respect to another IO. One control law is global, that is, the control law works (stable and convergent) for any initial condition. The remaining three control laws are local. The control laws are obtained by applying feedback linearization, while retaining non-linear characteristics. Each control law generates a profile (time history) of the control signal to produce a desired phase difference recognizable by a controller to respond to disturbances and to maneuver an underwater vehicle.

Abstract: The present invention is a submarine mast antenna controller for controlling a plurality of functions performed by an antenna mast of a submarine. The submarine mast antenna controller is a solid state electronic control unit on a single card that monitors various submarine mast antenna system sensors and motors, and controls electromechanical devices associated with the sensors and improves functionality over the former ACU system by consolidating control interfaces and indicators in one computer terminal via a VXI interface.

Abstract: A plurality of optical sensors are mounted to a housing made of optically conductive material. The housing seals the optical sensors from a water-filled tube which extends through said housing. The optically conductive material provides optical coupling with the water-filled cable tube whereby a plurality of light beams are directed through the housing and the water-filled tube in a predetermined pattern, which provides certainty of the absence or presence of a cable within the water-filled cable tube for a minimum cable diameter regardless of the orientation of the cable within the water-filled tube.

Abstract: An autonomous hydrophone position locating and target tracking system employing a string or array of acoustic hydrophone equipped apparatuses that are easily and rapidly deployed over the ocean bottom within a preselected volume of water. For each bottom residing hydrophone, a dedicated cable provides surface location based on satellite generated GPS positioning data. Special real time cable deflection algorithms resident in the base unit electronic processor are continuously updated using the velocity gradient inputs from several in-line velocimeters positioned at different depths along the cable. The shape of the tether cable and the resulting position of the bottom unit mounted hydrophone is then back calculated in real time in three dimensions from the known global position of the surface buoy.

Abstract: An apparatus for improving and increasing sustainable shear force capabilities at an interfacing surface between a rigid material and a flexible material is disclosed. The interface includes at least two superimposed components having different surface roughnesses. A coarse surface roughness component has a surface roughness about 3 orders of magnitude greater than that of a fine surface roughness component. The interface is useful for all types of devices with a rigid-to-flexible interface that needs to resist shear, tension, torsion, compression, or any disturbing steady-state or variable force or forces.

Abstract: An Unmanned Undersea Vehicle (UUV) docking system is provided in which the UUV is responsive to a first rotating light beam (which emits from a submarine) to begin a docking procedure. The UUV utilizes a photodetector to detect the first light beam and to guide the UUV toward the submarine by utilizing the first light beam. In one embodiment, the UUV reflects light from the first light beam back to the submarine. A photodetector on the submarine detects the reflected light to ascertain that the UUV is locked onto the first light beam. The submarine then stops rotating the light beam so that a trajectory of the UUV heads in the direction of a docking station which is positioned on the submarine.

Abstract: A method and system for detecting the location of an air/sea interface on an Instrumented Tow Cable (ITC) when distributed temperature measurements are provided. The air/sea interface is determined by estimating the variance of observed temperature in the proximity of each measurement cell. The method and system described herein uses a sliding variance across the entire cable length. The variance of the cell or cells in the area of the interface has been found to be large compared to other cells. Accordingly, the location of the air/sea interface is determined based on the location of the peak variance. The location of the air/sea interface is used in determining the catenary of the ITC.

Abstract: The invention as disclosed is an apparatus that controls the wake of stator blades on an underwater vehicle. The apparatus comprises one or more stator blades each with a movable trailing edge that when actuated in a controlled manner produces a periodic flapping motion upstream of a propulsion rotor. The controlled periodic flapping of the trailing edge the fills the stator blade wake enough to overcome the stator blade's own drag and fill its wake deficit. This has the effect of reducing the blade rate tonal noise of the propulsion rotor.

Abstract: The invention as disclosed is a method for mitigating spatial aliasing that takes advantage of the forward motion of towed array elements to overcome the frequency constraints imposed on beam forming by the spatial separation of the array elements. The method employs the motion of a towed array of hydrophones to generate at least one synthetic array element to compensate for spatial under sampling.

Abstract: The present invention provides methods for making an acoustic transducer. In one possible embodiment, a rigid inner shell is provided with a conductive exterior surface. Masking material is applied onto a first location on the conductive exterior surface of the rigid inner shell. Piezoelectric material is deposited over the conductive exterior surface of the rigid inner shell and the masking material. Conductive material is deposited onto the piezoelectric material. The masking material is removed. A first signal lead is attached to the first location on the conductive exterior surface of the rigid inner shell. A second signal lead is attached to the conductive material.

Abstract: An underwater data transmission system including arrays of nano-meter scaled photon emitters and sensors on an outer surface of an underwater platform. For the emitters, a laser is pulsed to correlate with data packets, providing a beam of photons at a prescribed frequency. Nano-scaled collecting lenses channel the incoming photons to photo-receptors located at a focal plane for the frequency at the base of each lens. A coating on the lenses absorbs photons at the frequency that are not aligned with the longitudinal axes of the lenses or tubes. Nano-wires connect the photo-receptors to a light intensity integrator. The integrator integrates the intensity over a surface area. The output of the integrator is fed to a signal processor to track and process the arriving digital packets.