Abstract: A device, system and method of use for the relative navigation in a fluid medium, the device having a receiver and a controller, the receiver capable of receiving signals through the fluid medium. The signals, produced by a source, are capable of undergoing Doppler shift, and the controller is capable of determining the Doppler shift of the signals and determining the bearing between the device and the source of the signals. The system further having a first vehicle capable of producing the signals and a second vehicle having the device and wherein the device determines the bearing of the second vehicle in relation to the first vehicle.

Abstract: A pressurization processing system that performs pressurization processing on a target by immersing the target in the sea or a lake, includes a housing body that is configured to house the target, a buoyancy body that is configured to float the housing body, a weight body that has a specific gravity greater than that of seawater or lake water, and a separation mechanism that separably connects the housing body and the weight body. In the system, the buoyancy body includes a housing bag having water permeability, and the housing bag houses a plurality of hollow glass spheres, and is immersed in the seawater or the lake water so that a space between the plurality of hollow glass spheres housed in the housing bag is filled with the seawater or the lake water.

Abstract: The system for positioning an underwater device including at least two surface transponders comprising a receiver for receiving radio signals transmitted by a geolocation system; each surface transponder comprising: an estimator for estimating at least one radio pseudo-distance; an attachment to a float; and a communicator for communicating information representative of the radio pseudo-distances; and an underwater acoustic transmitter; the underwater device comprising: a receiver for receiving information representative of the radio pseudo-distances; an acoustic signal receiver; a determinator for determining one or more acoustic pseudo-distances between at least two underwater acoustic transmitters and the underwater device; and a calculator for calculating the position of the device in a terrestrial frame of reference centered on one of the surface transponders.

Abstract: The present invention relates to a method of scheduling for an underwater wireless mobile network. Particularly, the present invention relates to a method of scheduling for an underwater wireless mobile network, whereby the method may consider a scheduling method that does not cause collision at a specific time domain, and improve network efficiency by receiving in a sink node a packet in a packet train form in consideration with a transfer velocity of a sound wave and a packet length rather than performing orthogonalization to avoid transmission time overlap at a specific time.

Abstract: An embodiment of the invention includes combining pseudorandom sweeps with an independent, or nearly independent, survey acquisition technique. Targeted design of pseudorandom sweeps can direct the majority of cross-correlation noise to lie outside key time-lags of the record (i.e., windows of interest). Embodiments of the invention are described herein.

Abstract: A seismic survey system for recording seismic data underwater. The system includes first plural buoys configured to descend to a first predetermined depth (H1) in water, at least one buoy having a seismic receiver for recording the seismic data; a first vessel configured to launch the first plural buoys; and a first acoustic system attached to the first vessel and configured to detect a position of the at least one buoy while underwater. The at least one buoy is instructed to maintain the first predetermined depth (H1) underwater while recording the seismic data.

Abstract: In an embodiment a semiconductor device correlates a received signal with a known pattern. A correlation output is used as a basis for forming a confidence reference level. The confidence reference level and the correlation output are compared to identify a peak in the received signal indicating that a present signal state of the received signal contains the known pattern.

Abstract: A submarine homing system includes an acoustic emitter configured to emit an acoustic signal comprising at least two narrow-band tones, each narrow-band tone having a respective predetermined center frequency. An acoustic receiver is configured to receive the acoustic signal from the acoustic emitter, and produce one or more receiver signals. A processor is operatively connected to the acoustic receiver. The processor is configured to process the receiver signals to calculate a direction between the acoustic receiver and the acoustic emitter.

Abstract: A system and method is provided for using acoustical pulses generated from an airborne laser source to locate objects under water. An array of acoustic sensors, such as passive sonobuoys at the ocean surface, is deployed in known or determinable locations by aircraft. Each area surrounded by acoustic sensors comprises a search cell, within which sonar scattering data can be used to locate objects. Following sonobuoy deployment, the aircraft uses the laser to rapidly generate many laser-acoustic pulse sources within each search cell, which in turn generate spherical acoustic pulses traveling through the water. The acoustic sensors receive the acoustic pulses, either on a direct path or on a scattered path after the pulse strikes an underwater object. The sensors record the acoustic signatures of the received pulses and transmit data of the recorded acoustic pulses to a processor such as processor on a nearby ship.

Abstract: A system and method is provided for using acoustical pulses generated from an airborne laser source to locate objects under water. An array of acoustic sensors, such as passive sonobuoys at the ocean surface, is deployed in known or determinable locations by aircraft. Each area surrounded by acoustic sensors comprises a search cell, within which sonar scattering data can be used to locate objects. Following sonobuoy deployment, the aircraft uses the laser to rapidly generate many laser-acoustic pulse sources within each search cell, which in turn generate spherical acoustic pulses traveling through the water. The acoustic sensors receive the acoustic pulses, either on a direct path or on a scattered path after the pulse strikes an underwater object. The sensors record the acoustic signatures of the received pulses and transmit data of the recorded acoustic pulses to a processor such as processor on a nearby ship.

Abstract: A communication system for obtaining predetermined information from an underwater terminal via a sonobuoy is provided. The system includes an underwater terminal for transmitting and receiving sound wave signals, a base station apparatus for transmitting and receiving radio wave signals, and a plurality of sonobuoys for transmitting and receiving the sound wave signals to and from the underwater terminal, and for transmitting and receiving the radio wave signals to and from the base station apparatus.

Abstract: A ballistic-acoustic transducer system includes a processor and one or more acoustic sensors. The sensors are positioned in a body of water and are in communication with the processor. The system is configured such that acoustic energy generated by a non-explosive projectile as it impacts the water, enters the water, and sinks through the water, is sensed by the one or more acoustic sensors, and the processor is configured to process the acoustic energy sensed by the one or more acoustic sensors.

Abstract: A ballistic-acoustic transducer system includes a processor and one or more acoustic sensors. The sensors are positioned in a body of water and are in communication with the processor. The system is configured such that acoustic energy generated by a non-explosive projectile as it impacts the water, enters the water, and sinks through the water, is sensed by the one or more acoustic sensors, and the processor is configured to process the acoustic energy sensed by the one or more acoustic sensors.

Abstract: A communication system for obtaining predetermined information from an underwater terminal via a sonobuoy is provided. The system includes an underwater terminal for transmitting and receiving sound wave signals, a base station apparatus for transmitting and receiving radio wave signals, and a plurality of sonobuoys for transmitting and receiving the sound wave signals to and from the underwater terminal, and for transmitting and receiving the radio wave signals to and from the base station apparatus.

Abstract: Methods and apparatus to provide sonobuoys that can be deployed on a sea bottom and surface upon detection of an object of interest. Upon reaching the surface, the sonobuoy can transmit information, such as position information, to a receiver on an aircraft, satellite, and/or remote location.

Abstract: A system and method is provided for using acoustical pulses generated from an airborne laser source to locate objects under water. An array of acoustic sensors, such as passive sonobuoys at the ocean surface, is deployed in known or determinable locations by aircraft. Each area surrounded by acoustic sensors comprises a search cell, within which sonar scattering data can be used to locate objects. Following sonobuoy deployment, the aircraft uses the laser to rapidly generate many laser-acoustic pulse sources within each search cell, which in turn generate spherical acoustic pulses traveling through the water. The acoustic sensors receive the acoustic pulses, either on a direct path or on a scattered path after the pulse strikes an underwater object. The sensors record the acoustic signatures of the received pulses and transmit data of the recorded acoustic pulses to a processor such as processor on a nearby ship.

Abstract: The invention, as embodied herein, comprises an improved portable maritime scoring and simulation system that comprises three or more buoys that are deployed in an area of water selected for maritime combat training. Attached to each buoy are a global positioning system receiver, an RF radio system, an acoustic analysis system, and a microprocessor. The acoustic analysis system is designed to capture an acoustic signature of ordnance impacting the water with predetermined characteristics. The system includes an RF radio repeater system linked to a system controller to control and monitor the elements of the system. In operation, when an acoustic signature is captured by the acoustic analysis system, the RF radio system, in one embodiment, transmits the time of the capture along with the GPS location of the buoy to the RF radio repeater system linked to the system controller.

Abstract: A method of deploying sonobouys includes providing an airborne aircraft having a computer and a plurality of sonobouys; making a contact with a submarine; determining a position of the submarine, a position error of the submarine and a speed of the submarine; inputting into the computer the airborne aircraft speed, a distance from the airborne aircraft to the submarine, the position error of the submarine, and a sonobuoy detection range; computing a flight time and flight distance to a first sonobuoy drop; computing a flight time, a flight distance and an airborne aircraft course to each subsequent sonobuoy drop to encircle the submarine with sonobuoys; displaying a total number of sonobouys needed, a total flight time to deploy the total number of sonobouys and a total flight distance to deploy the total number of sonobouys; deploying a first sonobuoy; and deploying additional sonobouys until the total number of sonobouys has been deployed.

Abstract: A borehole logging tool system includes a surface system, a logging array, and a logging cable providing power supply and data paths connecting the logging array to the surface system, wherein the logging array includes a series of discrete sondes connected together. The sondes in the logging array, for example a borehole seismic logging array, are connected to their neighbours by means of lengths of logging cable. Such cable can be the same as that connecting the logging array to the surface system. The logging array can also include a master controller module which communicates with the surface system and which includes a first controller module which connects to the surface system and a second controller which controls operation of the sondes in the logging array independently of any other borehole logging tools connected to the surface system.

Abstract: A device for center positioning a piazo element for the purpose of effectively reproducing the dynamics of a drum stick strike and feel when converting acoustical drums into electronic drums.

Abstract: A dipping sonar transducer housing includes a generally cylindrical housing (10) which is suspended at the end of a cable (12) connected to tile housing through a vibration isolation module (14) which includes springs (22) to damp out noise, particularly that from the supporting vehicle. The housing (10) contains an upper water-tight chamber (26) which contains circuit boards (28) and preamplifiers (30) which serve as amplification and multiplexing means for the hydrophones carried on extendible arms (96, 60, 88); a second water-tight chamber (35) immediately below the first chamber (26) contains an electric motor (36) which drives a hydraulic pump (38) which provides fluid under pressure to an accumulator (40). Movable vertically on the outside of the second chamber (35) is a piston (48) which drives a plurality of links (54, 56) which extend the receiver array.

Abstract: A well tool in accordance with the invention comprises an attenuation device which attenuates tube waves associated with an elastic wave emission and/or reception set (1, 12). The attenuation device comprises a bubble generator (2) which releases into the well a gas not readily soluble in the well fluid, slightly overpressured in relation to the hydrostatic pressure, in the form of calibrated bubbles which greatly attenuate the parasitic tube waves. The attenuation device is placed above or below the elastic wave emission and/or reception set having a plurality of pickups whose signals are acquired by a local electronic module (14) and/or a source of elastic waves such as a vibrator. A bubble trap (17) is preferably associated with the bubble generator (2) in order to limit the volume of gas to be generated in situ. The invention is applicable to VSP type seismic prospecting and acoustic logging.

Abstract: A system locates the elements of a randomly dispersed, untethered, array of sonobuoys from which are suspended active, transmitting, transducer elets and passive, receiving, transducer elements. The system comprises a data conditioning unit which receives high-frequency element-locating signals from a radio receiver, which may be located on an aircraft, and processes them so that they are quantized at its output. An acoustic delay processor, whose input is connected to the output of the data conditioning unit, correlates a reference signal R received from an active element suspended from the sonobuoy with a corresponding received signal from another element, active or passive, suspended from another sonobuoy.A position tracker, whose input is connnected to the output of the acoustic delay processor, calculates the relative position of each element of the random array from the propagation delays measured by the acoustic delay processor.

Abstract: A novel fault framework method and apparatus automatically computes the relationships between intersecting fault surfaces. When faults are loaded into the novel fault framework apparatus, all intersecting fault pairs are determined and the fault fault intersection lines are computed and stored. The intersecting fault pairs are presented and available for automatic calculation of the major/minor and above/below fault pair relationships. The geometry of both intersecting fault surfaces are examined on either side of the fault fault intersection line. This, in combination with the relative size of the faults, is analyzed to compute the major/minor and above/below relationships based on geologic assumptions and knowledge of the origin of the fault surface data. When the relationships between intersecting faults is defined, the minor fault is appropriately truncated.

Abstract: An acoustic tomography telemetry system and method allowing spatially averaged ocean temperatures to be measured in real-time. The system includes autonomous acoustic sources mounted on subsurface moorings and receivers that are either suspended from drifting surface buoys or cabled to shore. The telemetry method largely eliminates, in real-time, corruption of acoustic travel times due to wander of the source's mooring by shifting the start times of tomographic transmissions. Corrections to source wander are obtained without expending battery energy over and above that used in conventional tomography experiments. Standard techniques are used to correct clock errors at the source in real-time.

Abstract: A sensor for detecting acoustic energy emitted by a target is disclosed. The sensor comprises a housing including a plurality of transducers for receiving acoustic energy. The transducers are randomly deployed within a predetermined area around the housing, forming an array and a self-survey technique is utilized to determine the positions of the sensors. Beamforming techniques are utilized to analyze the acoustic energy detected by the transducers to provide the azimuth of a target and a class estimate of the target. A plurality of sensors may be utilized to provide target location, course and velocity.

Abstract: A system that extends the use of a navigation system which uses radio waves to a an environment which is otherwise inaccessible to radio-based position, location, or navigation services. This system provides beacons which dynamically determine their positions and broadcast data to any number of underwater users. By receiving and processing the beacon data or the signal upon which it is modulated, the user dynamically determines its own position within a geodetically-based time-space coordinate system. Extending externally-generated navigation information to an underwater user need not be limited to the Global Positioning System or its signal structure. Underwater extensions of LORAN, Omega, and other navigation services are also amenable to the technique.

Abstract: An acoustic array, useful for sonar, comprises a plurality of transducing ements which are free floating and not connected to each other. Means are provided for locating the position of each of the transducer elements. The acoustic array may be one-dimensional, that is, a line array, a two-dimensional array, or a three-dimensional array. In another embodiment of the acoustic array, the transducing elements are free-floating but connected to each other by a flexible tether, which limits the range of separation of one transducing element from any of the others. The locator comprises a centrally located element to which there are attached three horizontal rigid arms. On the end of each arm is a high-frequency acoustic transducer. Periodically, each of the transducers transmits a high-frequency broadband pulse. The pulse from each of the three transducers is unique and identifiable.

Abstract: A sonobuoy comprising: a container adapted to nest side-by-side and end-to-end with plural containers of the same configuration; and inflatable parafloat collapsed into an upper chamber of the container; compressed gas means in the container for inflating the parafloat; a hydrophone; a hydrophone suspending cable assembly; and release means for normally securing the hydrophone and the suspending cable assembly to the container and operable to release the hydrophone and suspending cable in response to deposition of the container in a body of water.

Abstract: An automatic attenuator for use in Sonobuoy Missile Impact Location System (SMILS) sonobuoys to separate re-entry which impact signatures from other acoustic phenomena is disclosed. The attenuator for the sonobuoy device is divided into a high gain, narrow band channel for detection of ping signals and a low gain, wide band channel for detection of impact signals. The output of the two channels are summed in a summing amplifier. A switch is provided to turn off the high gain channel whenever received signals are large enough to cause a comparator circuit to activate a time which turns off the switch for 15 seconds time. Thus, the stronger impact signals are distinguished from other random signals.

Abstract: Three or more listening devices (A1, A2, A3) are dispersed over the water area where the location of a sound source is to be determined, and transmit radio signals over respective channels to a master station upon detecting sound. The master station correlates the signals from selected ones of the listening devices to derive the position of the sound source relative to those listening devices. If the positions of those listening devices are unknown, for example if the devices are floating free, their positions are determined by the master station by comparing the relative times at which an identifying radio signal transmitted by each listening device is received by the master station directly and relayed from each of two stationary radio stations with known positions. The listening devices may also be provided with receivers for receiving radio command signals from the master station, for example relating to activation of certain listening devices and assignment of radio channels.

Abstract: A beamforming method and apparatus utilizing a plurality of sensing elements which are free to take up random positions. Each sensing element generates output signals in response to sensed radiation. The signals are fed to a data process or which generates Fourier frequency components of each output signal and selects a Fourier frequency component for each given radiation frequency to form a group of frequency components. The data processor performs a spatial convolution, interpolation and spatial Fourier transform followed by an averaging procedure in order to obtain an output signal which is indicative of the far field radiation power as a function of angle thus providing the desired beamforming information.

Abstract: By incorporating a Global Positioning System (GPS) receiver into the electronics of an active or passive sonobuoy for determining a geoposition of each sonobuoy comprising an array of sonobuoys or a sonobuoy field, the position of each sonobuoy can be ascertained as the original position of the line of sonobuoys forming the array changes due to wind, sea state and currents. The GPS geoposition of the individual sonobuoys is transmitted to as receiving vehicle along with the acoustic signal obtained by the sonobuoy sensor. Utilizing an onboard computer, the receiving vehicle can compute a synthesized coherent array position. The military P(Y) code transmitted by the GPS satellites is utilized to determine the geoposition of the sonobuoy relative to the other sonobuoys to a degree of accuracy of 2 to 3 meters.