Abstract: A method is presented for identifying clutter in an image such as a sonar age. A detection scheme identifies portions of the image having a signal-to-noise ratio greater than a given threshold. A classification scheme is then applied to each such portion to generate fractal feature values associated therewith in order to classify the portion as a target or non-target. For clutter identification, each portion is assigned to a group based on a distance from the position of each portion to another of the portions that is its nearest neighbor. A series of tests are then performed for each group using the fractal feature values associated with each portion in each group. A failure of any of the series of tests by a group identifies each portion associated with that group as clutter in the image.

Abstract: An efficient sparker for a pulse powered underwater acoustic source for msweeping is capable of repetitive discharges at about 15 Hz for at least one hour without replacement or maintenance. The sparker has a tubularly-shaped cathode spaced apart from an elongate anode that coaxially extends the length of the tubularly-shaped cathode and a cylindrically-shaped insulator that fills the space between the cathode and anode. The cathode, anode, and insulator are secured to a collar and are shaped to have minimal drag when towed through the water at speeds up to 35 knots. The configuration and selection of fabrication materials for the sparker assure that a nominal constant gap is maintained between the cathode and anode.

Abstract: An air-delivered infrared anti-ship missile decoy is delivered from an aiaft to a desired location below sea surface ahead of advancing forces and then activated at a later time by a remotely-transmitted encoded signal to separate a payload assembly from the remainder of the decoy, float the payload assembly on the sea surface and then produce a relatively large infrared plume above the payload assembly and atop the sea surface that provides an infrared signature for decoying and deception purposes.

Abstract: A sound transducer, which may be a microphone or a speaker, is constructed using a metallic film sandwich of piezoelectric film as the active element. The sandwich is laminated to a flat inflexible substrate, such as a printed circuit board, over substantially its entire surface area, so that it operates as a transducer without flexing the piezoelectric film. Since the piezoelectric film is less sensitive in this mode than when it flexes, either the area of the sandwich must be large, or, as a microphone, the transducer must be subject to powerful sound waves. Such powerful sound waves are most easily achieved by either putting the microphone in physical contact with the sound source or placing the microphone in a contained pressure-field with the sound source. This entire package is then provided with impedance matching to connect it to an external point where the resulting signal can be used, is provided with a ground shield, and is encased in waterproof layers.

Abstract: A reusable gas-powered war game land mine has at least one launch tube with ne or more projectile(s) loaded therein. A compressed gas reservoir and rupturing device are provided with the rupturing device being movable in relationship to the seal of the compressed gas reservoir. A triggering mechanism is coupled to the rupturing device to move the rupturing device so that it impacts the seal when the triggering mechanism is activated. The rupturing device can define a channel through which the compressed gas is directed to the breech end of the launch tube(s) when the seal is broken. As a result, the compressed gas enters the breech end of the launch tube(s) to propel the projectile(s) therefrom.

Abstract: An aim verification method and system utilize an imaging lidar that transs a first beam of radiation within the imaging lidar's field of view. Reflected backscattered energy associated with the first beam within the field of view increases in an area thereof when a target is present therein. A radiation source is coupled to a gun and transmits a second beam of radiation in line with the aimpoint of the gun towards the area of increased reflected backscattered energy associated with the first beam. The second beam has a greater energy density than the first beam and has a cross-section that is smaller than the target. An energy detector is used to sense the reflected backscattered energy associated with the second beam. The gun is aimed at the target when the reflected backscattered energy associated with the second beam is greatest in the area of the field of view of increased reflected backscattered energy associated with the first beam.

Abstract: An improved hydrostat constructed on a silicon wafer by microfabrication methods similar to those used for integrated circuits and other devices. A thin section of the wafer acts as a diaphragm, responsive to pressure of ambient water. A lever arm is affixed at its first end to one point on the surface of the wafer and extends over the diaphragm, so arranged that the lever arm will be forced away from the wafer when pressure is applied to the diaphragm. The second end of the lever arm is moved by the diaphragm so that it moves further from the wafer, by a factor of the mechanical advantage of the lever. When the second end moves away from the wafer, it mechanically releases a lock, allowing an ordnance device to which the hydrostat is attached to arm.

Abstract: An insulation jacket is provided for a breathing gas device. A first jacket ortion wraps completely about the device's cylinder and gas delivery valve. A second jacket portion wraps about a high-pressure regulator coupled in-line with the gas delivery valve and a plurality of gas delivery conduits extending from the high-pressure regulator. The first and second jacket portions are formed from a flexible insulating material of laminate construction. A plurality of fastening strips, e.g., hook-and-loop fastening strips, cooperate with first and second jacket portions after they are wrapped about the respective portions of the breathing gas device.

Abstract: An automatic control system is disclosed herewith which causes the notch ter incorporated in a sonar system or any other appropriate utilization apparatus to be electrically by-passed in response to a predetermined minimum doppler present within a data signal being filtered thereby. It includes such uniquely combined elements as envelope detectors, rate-of-decay and rate-of-rise amplifiers, bistable multivibrators, an inverter, and an AND gate for adjusting the position of a selector switch connected for alternately electrically by-passing the notch filter. In addition, the gain of a variable gain amplifier disposed within an automatic gain control loop that includes the aforesaid elements and notch filter may be optionally employed to regulate the gain of the data signal supplied to said notch filter in correspondence with the by-passed and non-by-passed conditions thereof.

Abstract: Aerial training flare or flare simulator comprising a polymeric case, a begradable polymeric candle housing, and a candle comprising a pyrotechnic illuminant and an environmentally friendly, fast-burning ignition composition. An expulsion cartridge ejects the candle and the candle housing while the case is retained on the launching aircraft. The only major component of the flare which falls to earth is the partially melted candle housing, which is biodegradable and thus reduces requirements for environmental cleanup.

Abstract: A method of identifying and classifying pre-detected target candidates in an image using pixel intensity and a fractalization process applied to the image. A raw analog image is digitized and normalized. The normalized pixel intensity content of the image is converted to fractal dimensions using a small and a large fractal box, sequentially. An array of special fractal features satisfying predetermined classification thresholds is prepared from the fractal dimensions for each box centered about each pre-detected target candidate in the image, thus classifying the detected objects as targets.

Abstract: A multiconductor continuity and intermittent fault analysis system that sects the cable to controlled environmental stress stimuli, such a vibration at controlled frequencies, during testing. Multiconductor cables used for the transmission of digital data and control signals include multiple individual conductors terminating at both ends in pins or sockets that are grouped together in a connector. Physical defects in these cables can be permanent, or they can be intermittent faults, such as temporary breaks or shorts caused by vibrational stress on the cables. By vibrating the cable under test and measuring continuity rapidly enough to detect short-term anomalies, even intermittent faults are located.

Abstract: A pulsed-transmission, single frequency echo-ranging sonar system has a w-beam acoustic projector with sharp cutoff of energy radiated in directions other than the desired field of view and a nearly constant amount of acoustic energy throughout the desired vertical field.

Abstract: A pulsed-transmission, echo-ranging sonar system of the side scanning type ses a synthetic aperture to form search beams. The system uses multiple projectors, and a multistatic hydrophone array and a four transmission sequence, each originating at the same location thus permitting a shorter array which can travel twice as fast as conventional systems while achieving grating lobe suppression.

Abstract: The secure communication keying system has a noise generator whose output a predetermined finite band of noise within, for example, the zero to eleven hundred cycle per second range. The noise generator may be a pseudorandom noise generator that is synchronized with a given clock frequency. The output of the system may have noise-like characteristics, but it is encoded with any type of intelligence desired to be transmitted. The output signals simulate the ambient noise occurring within the communication medium and has the same frequency spectrum regardless of the frequency of the modulating signals supplied thereto.

Abstract: A sensor for sensing the location of objects buried in the loose sediment in the bed of the sea. A hollow, cylindrically symmetric, conductive shell is used to inject current into seawater at its tips along its axis. A sensor coil oriented along the axis ignores all magnetic fields except those along the axis, and is used to measure return signals. This is particularly useful in detecting dielectric objects buried in the sediment and in rejecting motion relative to the seabed.

Abstract: A DC superconductor quantum interference device (i.e. DC SQUID) is used in a flux-locked loop as a sensitive detector of magnetic flux. Prior art devices of this sort had a transfer function which was frequency-limited by the transfer function of impedance matching circuitry which is used to connect the DC SQUID with the first preamplifier, which amplifies the DC SQUID signal before it is applied to a detector circuit. The present invention corrects this frequency limitation by creating a compensating circuit having a transfer function which is the inverse of that of the impedance matching circuitry, and inserting it in the system after the first preamplifier and before the detector circuit.

Abstract: An optimal control system for canceling the undesired responses of a linear istributed-parameter system in response to an input stimulus. The control system is optimally distributed and its design is based on the extension of the Pontryagin's maximum principle for a lumped-parameter system to a distributed-parameter system. The technique is to transform the stimulus-to-undesired-output transfer function of the distributed-parameter system into a multidimensional discrete state-space model, and to require a performance criterion to be defined. Theorems have been established to give conditions for asymptotic stability of the closed-loop distributed-parameter system, and to set up weighting factors for the performance criterion. An optimal distributed-control system can force the states of the distributed system to behave according to the prescribed performance criterion regardless of the boundary and initial conditions.

Abstract: A method and apparatus for cathodically protecting basic steel and iron sctures located in an electrolyte without requiring any auxiliary backup power means on a continual basis. The method and impressed current type system use a PV solar panel array to supply dedicated DC operating current after the structure is first initially temporarily provided with preconditioning polarization on a one-time-only basis for a predetermined extended continuous time period, such as from about 3-7 days, by a separate non-solar DC generating means, thereby impressing it with the requisite beneficial relatively high negative potential which completes the initial polarization. The temporary power source is then permanently disconnected and the solar array is promptly connected in circuit to continue to provide the requisite high negative beneficial potentials which were achieved by the preconditioning polarization, and to thereby maintain the cathodic protection.

Abstract: A submersible boat is provided which utilizes a planing boat hull with a sharp bow and blunt stern. The submersible boat performs as a planing boat until it nears the target location. Then, the boat submerges in order to avoid detection. After this vessel submerges, it travels with the blunt end forward and the sharp end aft.