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: A barge strike system for clearing an obstacle-filled region of water inces a floating barge having at least one hollow region defined therein. The barge is equipped to move under its own power to the obstacle-filled region at various speeds, including speeds in excess of minimum planing speed. Explosive material is contained in the barge's hollow region(s). A plurality of detonators are coupled to a top surface of the explosive material and are initiated to generate a coalesced planar wave downward through the explosive material.

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 transducer array is constructed from a constant arc length portion of a ght circular cylindrical shell of piezoelectric transduction material. The constant arc length portion is segmented evenly along the length thereof to define a plurality of transducers. The transducers can be in the free field or mounted on a planar baffle.

Abstract: A self-contained underwater breathing loop apparatus for an oxygen rebreather includes a breathing bag formed to act as a compliant volume and a semipermeable membrane arranged to divide the breathing bag into a first chamber and a second chamber. A breathing hose is connected between a mouthpiece and the first chamber of the breathing bag to conduct exhaust breath from the diver thereto. The semipermeable membrane is formed to allow helium in the diver's exhaust breath to pass therethrough while preventing oxygen in the exhaust breath from being transported from the first chamber into the second chamber. A relief valve in the second chamber allows helium in the second chamber to be expelled into the water. A CO.sub.2 scrubber is in fluid communication with the first chamber of the breathing bag. A helium supply in fluid communication with the CO.sub.2 scrubber for supplying helium to the breathing loop through a metering valve.

Abstract: A coherent light beam is split to form optical signals that follow separate ptical paths to a light beam combiner. One optical signal is frequency modulated reference signal. The optical signal is directed to the object being detected. A light collector is arranged to collect light that has impinged upon the object. The collected light from the object and the reference signal are optically heterodyned. The heterodyned signals are detected by a photodiode that produces electrical signal that are processed to determine the shape of the object being detected.

Abstract: An apparatus and method for beamforming for a toroidal volume search sonar. onar array vehicle motion is used to reduce reverberation by fixing beams geometrically in space to prevent beam contact, prior to a specified range, with the sea surface or sea bottom interfaces. Reverberation is further reduced by creating a composite beam from one scanned beam containing the target dominated by surface reverberation and another dominated by bottom reverberation. A correlation and averaging procedure is applied to the two scanned beams to further reduce the reverberation in the composite beam. To further reduce reverberation, the two beams selected for correlation and averaging processing are chosen such that the number of common elements associated with the two beams is a minimum within a given angular separation.

Abstract: Method and apparatus for localization and characterization of a magnetic rce including source strength and orientation. Samples of five tensor gradiometer signals from a straight-line track are used to construct a polynominial fit to each gradient tensor component with the variable being either time or track distance. Polynomial expressions are used to estimate rate of change of each gradient tensor component at the current sample, providing five numbers. Current samples of the gradient tensor components form a second five number set. An invention inversion process produces solutions for instantaneous bearing vector from the gradiometer to the source, direction in space of the source magnetic moment vector, and ratio of the magnetic moment vector magnitude to the fifth power of range from gradiometer to source from the gradient tensor component rate samples.

Abstract: A system and method are provided for multiplexing/demultiplexing asynchros high-speed digital data and asynchronous low-speed digital data. A first digital signal processor (DSP) receives complete low-speed data messages and is programmed to assemble each complete message into data blocks in accordance with a block format. Each data block is identical in size and includes provisions for a header that identifies the data assembled therein. A second DSP has a plurality of I/O ports, each of which has a direct memory access (DMA) associated therewith. One of the I/O ports is coupled to the first DSP to receive each complete message assembled into data blocks. The other I/O ports are coupled to a second plurality of channels transmitting asynchronous high-speed digital data. The DMAs associated with the other I/O ports are configured to assemble the high-speed data into data blocks in accordance with the same block format used for the low-speed messages.

Abstract: A marker buoy includes a base with a post coupled to and extending theref, a line attached to the post and is wrapped about a portion thereof, and a float attached to the line and fitted over the wrapped portion of the post. When the marker buoy is deployed near the bottom of a body of water, the base sinks to the bottom and the float rises to the surface of the body of water causing the line to unwrap from the post. The line length is user set as a function of depth and speed of the surface current at the time of buoy placement and use.

Abstract: A device is provided for modifying the temperature of a breathing or other as supplied through a conduit. A heat exchanger is mounted in-line with the conduit. A thermoelectric device has first and second thermally conductive plates separated by at least one thermoelectric couple. The first thermally conductive plate is in thermal contact with the heat exchanger. A phase change material is in thermal contact with the second thermally conductive plate. A voltage is applied to the thermoelectric couple(s) to maintain the first and second thermally conductive plates at different temperatures. The phase change material changes from a first phase to a second phase at a phase change temperature that is selected to be between the different temperatures of the first and second thermally conductive plates.

Abstract: A limited rotation connection device includes a housing defining a central ole extending therethrough and a central shaft extending through the central hole of the housing and being rotatably mounted to the housing, the housing also defining an annular slot surrounding and extending in substantially perpendicular relation to the central shaft. The device also includes an elongated flexible communication element disposed in the annular slot of the housing and having a first opposite end portion mounted to the central shaft and a second opposite end portion mounted to the housing. The communication element is collapsible and expandable upon rotation of the central shaft relative to the housing so as to allow limited rotations of the opposite end portions of the communication element relative to one another before reversing rotation direction becomes necessary. The first opposite end portion of the communication element is connectable to a first external communication device.

Abstract: An iterative process to determine the wavelet function and combination of ales of the function which provides data where there is a large separability compared to the separability of the data set prior to processing. Wavelets are selected for inclusion in a library in accordance with predetermined criteria and then applied to a digitized signal by convolution to perform digital filtering. The convolution of each wavelet is performed for the number of times dictated by the coefficients of the wavelet for each of the input signal samples. Separability of the wavelet implemented digital filtration is calculated as a percentage for each wavelet. The separation data is stored in memory until the iterative process is applied to all wavelets. The separability data is then examined to identify the wavelet producing the greatest separation. The data separability is estimated using a likelihood ratio after the probability densities for each of two sets of profile data are estimated.

Abstract: A heated decompression shelter for use by a diver underwater during decomssion at the end of a cold water dive. The heated decompression chamber provides a micro-environment within an enclosure for thermal protection during decompression stops in cold water, some of which can be of relatively long duration following relatively deep dives in near freezing water.

Abstract: A back-reinforced two-piece upper torso assembly for an articulated diving uit. The upper torso assembly includes a lower hollow rigid body of rounded shape for housing a diver's upper trunk, an upper hollow rigid body of rounded shape for housing a diver's head and being seated upon the lower hollow rigid body, and a clamping and sealing mechanism releasably coupling the upper hollow rigid body to the lower hollow rigid body about adjacent seated portions thereof so as to form a watertight joint therebetween wherein the upper hollow rigid body can rotate relative to the lower hollow rigid body. The upper torso assembly also includes a reinforcement structure connecting the upper hollow rigid body to the lower hollow rigid body along adjacent rear portions thereof so as to permit a lifting load applied to the assembly during water entry and exit to transfer to the lower hollow rigid body in such manner as to avoid stressing the watertight joint therebetween.

Abstract: A method for ocean surface delivery of ordnance and clearing of explosive mines and obstacles from a navigable sea channel includes the step of providing quantities of ordnance adapted to survive impact and prolonged immersion in sea water and to arm in response to release from a mobile ocean surface vehicle and to pressure actuation upon submersion to a desired depth in sea water and then to detonate in response to receiving a preselected signal transmitted to the ordnance from a standoff location. The method also includes the step of delivering the quantities of ordnance from a mobile ocean surface vehicle toward multiple sites in a navigable sea channel containing obstacles and explosive mines therein so as to cause arming of the ordnance followed by impact thereof with the navigable sea channel and submersion and emplacement thereof at the multiple sites in the navigable sea channel.

Abstract: A marine pressure minesweeping and ship signature simulating vehicle having n inflated substantially doughnut shaped tubular float surrounding a pressurized air-filled cavity. The lower part of said float rides on the surface of the water and the upper part thereof is closed with a resilient membrane, upon the upper side of which is mounted water ballast container means, which is sufficiently open at the top to allow the water ballast to be ejected therefrom, as a result of a considerable increase in air pressure occurring in the aforesaid air filled cavity, due to a mine explosion. A motor driven fan maintains a suitable air pressure in said air-filled cavity at substantially all times, and drive and steering means are mounted on the vehicle in such manner as to enable it to be navigated along a desired course.

Abstract: A one piece dental appliance custom molded to a particular patient's denton for resolution of sleep apnea. The invention features a transpalatal strap extending from one side of the appliance to the opposite side joining the opposing lingual surfaces. The transpalatal strap continuously and uninterruptedly extends between and joins the right and left dental retentive portions of the appliance from one side of the maxillary arch to the opposite side of that arch. The appliance is fabricated from dental acrylic by the dentist in the office and requires a posterior access articulator to adapt acrylic lingually between the maxillary and mandibular casts.

Abstract: A hand emplaced underwater mine penetration system includes a launching ambly and a munition assembly. The launching assembly includes a firing device which receives a magnetic or acoustic signal from a standoff signal generator, and a launch tube having a forward open end, an opposite rear end connected to the firing device and a bore extending between the ends. The munition assembly is adapted for insertion within and firing from the bore of the launch tube of the launching assembly and includes a cartridge having explosive elements therein and a fuze disposed at a forward end of the cartridge and adapted to detonate and explode the explosive elements in the cartridge upon impact with an underwater mine.

Abstract: An apparatus for eliminating scattered light from unscattered light (sign in the reflection from a laser-illuminated target and its ambient. The apparatus uses a laser selected for maximum Lorentzian to Gaussian mode content, a stable interferometer having an optical path difference twice the distance to the first zero in the Gaussian pattern of the scattered interferogram, and performs subtraction of the background or scattered interferogram from the unscattered or signal interferogram. The laser is multi-mode and the interferometer is a Fizeau wedge having an optical path difference equal to twice the distance to the first zero in the Gaussian interferogram. The method of making the apparatus is provided.