Abstract: Embodiments of the present invention provide a navigation system which, on the one hand, is arranged on sides of the underwater vehicle/AUV and, on the other hand, includes a surface transmitter as a counterpart. The two units communicate with each other such that the surface transmitter emits its signal directed to the position of the underwater vehicle and/or that the surface transmitter follows the underwater vehicle to improve the position determination capability.

Abstract: A sonar-integrated IoT device, the IoT device including one or more sonar sensor modules (101), corresponding to information acquisition in different spatial directions; the IoT device is in communication connection with an external signal processing unit through a wireless network, and sends unprocessed or preliminarily processed spatial information to the signal processing unit. The advantages of the invention include: simple and flexible arrangement of sonar sensor module (101) nodes, which are integrated with wireless IoT devices such that spatial information may be acquired locally; and at the same time, ease of implementation of large interval arrangement and large quantity arrangement of sonar sensor modules (101), covering a variety of spatial locations, thereby providing wide coverage of spatial detection range, and acquisition of abundant signal samples, such that better spatial information extraction algorithms may be implemented in the signal processing unit.

Abstract: An underwater navigation algorithm (UNA) uses acoustic signals transmitted in the ocean from sources at known positions to compute a position underwater for a vehicle that requires no initial a priori position or any ocean sound speed information or any initial GPS position that would require surfacing. The UNA consists of two parts, (1) the Cold Start Algorithm (CSA) and (2) the CSA with Modeling (CSAM). The underwater vehicle needs to be equipped with only a single hydrophone acoustic receiver and an onboard processor. The CSA requires only measuring the travel time of the end of the arrival coda (EOC) from each of the sources to compute a position. The CSAM is a post CSA procedure to calculate a higher accuracy position using the CSA position.

Abstract: Buoyant tail section of a geophysical streamer. At least some of the example embodiments are methods of performing a geophysical survey in a marine environment, the method including: towing an active section of a geophysical streamer in the marine environment, the active section having a buoyancy; towing a tail section, the tail section coupled to a distal end of the active section, the towing of the tail section by way of the active section, and at least a portion of the tail section having a buoyancy that is both positively buoyant and greater than buoyancy of the active section; towing a tail buoy in the marine environment, the tail buoy coupled to a distal end of the tail section, and the towing of the tail buoy by way of the tail section; and gathering geophysical survey data by way of the active section.

Abstract: An underwater connector includes a first component and a second component, wherein the components are operable to be coupled together in operation in a first coupled state, and operable to be mutually spatially separated in a second uncoupled state. The first and second components each include communication arrangements which are operable to provide wireless communication between the first and second components when in their first coupled state. The first and second components include a power transfer arrangement for transmitting power between the first and second components. The power transfer arrangement includes inductive coupling devices and/or capacitive coupling devices, wherein the power transfer arrangement is implemented substantially as an annulus, for example circular, elliptical, or polygonal, on the first and second components together with the communication arrangements being disposed within the annulus and/or around a periphery of the annulus.

Abstract: The present disclosure provides systems and methods for indicating battery damage. A battery may comprise an odorant and/or visible indicator material configured to be released in response to battery damage. The battery may be configured to release the odorant and/or visible indicator in response to damage to the battery housing, a cell or cells in the battery, a seal of the battery, or any other specific component of the battery. The odorant and/or visible indicator may be stored in free space in the battery housing, a battery cell, or other battery component. The battery may be configured to emit an audible and/or visible indication of battery damage in addition to releasing the odorant and/or visible indicator.

Abstract: The present disclosure provides systems and methods for indicating battery damage. A battery may comprise an odorant and/or visible indicator material configured to be released in response to battery damage. The battery may be configured to release the odorant and/or visible indicator in response to damage to the battery housing, a cell or cells in the battery, a seal of the battery, or any other specific component of the battery. The odorant and/or visible indicator may be stored in free space in the battery housing, a battery cell, or other battery component. The battery may be configured to emit an audible and/or visible indication of battery damage in addition to releasing the odorant and/or visible indicator.

Abstract: There is provided an underwater measurement system (20, 30, 40) for monitoring an underwater region (10). The system (20, 30, 40) includes a sensor assembly operable to sense at least one physical variable in the region (10) for generating at least one corresponding sensor signal, and a data processing arrangement (170, 510, 520) for processing the at least one sensor signal to generate processed data for presentation and/or logging. The sensor assembly (20) includes one or more voltage sensors (190) configured to sense electric fields present in the underwater region (10) and provide information in the at least one signal indicative of the electric fields. Moreover, the sensor assembly (20) includes one or more hydrophones (200) operable to receive sonic energy generated in the underwater region (10) and to include corresponding information in the at least one sensor signal for communicating to the data processing arrangement (170, 510, 520).

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: The present invention generally relates to a sonar fish finding system. Specifically, this invention relates to a sonar device which attaches to a fishing line and floats on the water like a fishing bubble, float, or bobber. The sonar device pairs with a wireless computing device over a Bluetooth Smart (also known as Bluetooth Low Energy) connection to provide information to a fisherman about what is under the surface of the water. In some embodiments, processing may be done on subsets of sonar data samples in order to allow for processing a complete result without requiring storage of the entire set of data samples at once. In certain embodiments of the present invention, the sonar device sends data to a remote computing system either directly or indirectly through a wireless computing device. The remote computing system also sends the wireless computing device information about both real-time fishing hotspots, and fishing hotspots predicted based on historical data and current conditions.

Abstract: A method, apparatus and system are provided to permit an aerial asset to determine its current location and to, in turn, locate and track a target even as efforts are made by others to jam or otherwise hinder offboard communications that may prevent reliance upon GPS or other positioning systems. A method includes receiving, at a navigation control vehicle, information regarding the relative position of a target with respect to each of the at least two sonobuoys. The method also determines a relative position of the target with respect to the navigation control vehicle at least partially based on the information regarding the relative position of the target with respect to each of the at least two sonobuoys. The method provides information regarding the relative position of the target to an aerial asset to facilitate location of the target by the aerial asset.

Abstract: Various embodiments of the invention provide a buoy and system for monitoring divers and other underwater objects. In many embodiments, the buoy has capabilities to monitor a diver, obtain position information about the diver and use that information to move itself to an effective range for continued monitoring. The buoy can connect and communicate with a communication device attached to a diver to communicate, position, biometric and other data. In one embodiment, the buoy comprises a propulsion system for propelling the buoy, an acoustic communication module for communicating with the diver and a propulsion controller for controlling the propulsion system to move to the effective range. Other embodiments provide a power generation system using a power generating buoy comprising an inertial weight, an energy converter and a connecting linkage. The system may comprise a single or multiple buoys and can include an electrical storage such as an electrical battery.

Abstract: The present disclosure relates to determining the attenuation of an electromagnetic signal passing through a conductive material. An antenna is provided and placed in relatively close proximity to the conductive material. An alternating current is passed through the antenna and the impedance of the antenna is measured. The attenuation is determined using the measured impedance. A single frequency measurement may be made, or multiple measurements using different frequencies may be made. Grouped parameters based on properties of the material and the frequency of the current are used to relate the coil impedance to the attenuation. A current frequency for which the ratio of the antenna's resistive part of the impedance to the angular frequency of the current is substantially insensitive to at least one of the parameters is preferred.

Abstract: Described herein are methods and devices for underwater deployment of a structure. For example, the embodiments described herein are particularly focused on sonobuoys that are configured for autonomous deployment in an underwater environment. One embodiment provides a sonobuoy having a plurality of arms, which are in some embodiments telescopic. The sonobuoy is configured such that, upon deployment in an underwater environment, the arms extend and rotate from a collapsed storage configuration to an operative configuration. The rotation is brought about by way of tension in petal lines, which extend between an innermost telescopic segment of each arm and a central tether line intermediate the arms and a buoyancy device.

Abstract: A sonar buoy includes a fuselage having a tube-like shape, one or more wings coupled to the fuselage, an engine coupled to the fuselage and operable to propel the sonar buoy through flight, and a guidance computer operable to direct the sonar buoy to a predetermined location. The sonar buoy further includes a sonar detachably coupled to the fuselage and forming at least a part of the fuselage, and a rocket motor detachably coupled to the fuselage. The one or more wings are operable to be folded into a position to allow the sonar buoy to be disposed within a launch tube coupled to a vehicle and to automatically deploy to an appropriate position for flight after the sonar buoy is launched from the launch tube. The rocket motor propels the sonar buoy from the launch tube and detaches from the fuselage after launch.

Abstract: An underwater investigation system may include a host ship, a UUV including a propulsion device and a steering device, and at least one sonar system. The system may further include a guidance controller configured to initiate sonar range measurements between the host ship and the UUV using the at least one sonar system, and estimate a respective UUV position state relative to the host ship at the initiation of at least some of the sonar range value measurements to define a series of successive UUV position state estimates. The guidance controller may be further configured to update UUV position state estimates in the series based upon completion of their respective sonar range measurements, propagate the updates to subsequent UUV position state estimates in the series, and control the propulsion device and the steering device to guide movement of the UUV relative to the host ship based upon the updated position state estimates.

Abstract: Various embodiments of the invention provide a buoy and system for monitoring divers and other underwater objects. In many embodiments, the buoy has capabilities to monitor a diver, obtain position information about the diver and use that information to move itself to an effective range for continued monitoring. The buoy can connect and communicate with a communication device attached to a diver to communicate, position, biometric and other data. In one embodiment, the buoy comprises a propulsion system for propelling the buoy, an acoustic communication module for communicating with the diver and a propulsion controller for controlling the propulsion system to move to the effective range. Other embodiments provide a power generation system using a power generating buoy comprising an inertial weight, an energy converter and a connecting linkage. The system may comprise a single or multiple buoys and can include an electrical storage such as an electrical battery.

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 method for improving the bit error rate in digital transmissions of sonobuoy sensor data from a sonobuoy to a receiver platform includes computing a send checksum on a frame of sonobuoy sensor data, copying the frame of data and checksum into a plurality of subframes, delaying one of the plurality of subframes for a predetermined period, multiplexing the delayed subframe with the plurality of subframes into a transmit frame; and transmitting the transmit frame. The invention is particularly suited to improving the reception of legacy sonobuoy receivers in littoral waters where radio frequency interference and signal propagation is a severe problem.

Abstract: Described herein are methods and devices for underwater deployment of a structure. For example, the embodiments described herein are particularly focused on sonobuoys that are configured for autonomous deployment in an underwater environment. One embodiment provides a sonobuoy having a plurality of arms, which are in some embodiments telescopic. The sonobuoy is configured such that, upon deployment in an underwater environment, the arms extend and rotate from a collapsed storage configuration to an operative configuration. The rotation is brought about by way of tension in petal lines, which extend between an innermost telescopic segment of each arm and a central tether line intermediate the arms and a buoyancy device.

Abstract: A method for improving the bit error rate in digital transmissions of sonobuoy sensor data from a sonobuoy to a receiver platform includes computing a send checksum on a frame of sonobuoy sensor data, copying the frame of data and checksum into a plurality of subframes, delaying one of the plurality of subframes for a predetermined period, multiplexing the delayed subframe with the plurality of subframes into a transmit frame; and transmitting the transmit frame. The invention is particularly suited to improving the reception of legacy sonobuoy receivers in littoral waters where radio frequency interference and signal propagation is a severe problem.

Abstract: A hydrophone array includes an inflatable shaped housing enclosing an interior space and formable between a collapsed configuration and an expanded configuration, a framework of compliant material disposed within the interior of the inflatable housing, and a plurality of hydrophones attached to the compliant material at respective positions, wherein said hydrophones are arranged in a predetermined geometric array when the shaped housing is in the expanded configuration. Also provided herein is a system and method for deploying the hydrophone array.

Abstract: A system for determining the directional properties of surface waves or internal waves of a fluid medium includes a sonar system having a plurality of transducers for generating respective, separate acoustic beams and receiving echoes from one or more range cells located substantially within the beams; and a computer program for determining the directional properties associated with the surface waves or internal waves from the received echoes, wherein the computer program determines along-beam velocities along the separate acoustic beams and combines the along-beam velocities to form an equivalent orbital velocity vector. The system is mounted on or in a sub surface buoy that can move or rotate during measurement and includes a motion sensor measuring six degrees of freedom to account for horizontal velocity and vertical displacement in the subsurface buoy mounted sonar system.

Abstract: Disclosed is a system, and a method of operation thereof, which improves the RF link employed between a transmitting sonobuoy and an associated receiving aircraft. The sonobuoy receives acoustic information from hydrophones and transmits this information to the aircraft, via beams having a predetermined frequency spectrum. The system breaks the total frequency spectrum of the beams into sub-bands. The sub-bands are multiplexed on the RF link interconnecting the sonobuoy to the aircraft. More particularly, the frequency spectrum defining an acoustic bandwidth of about 750 Hz is broken into a selected number (e.g., 6 or 4) of sub-bands and multiplexed onto and forming the RF link.

Abstract: Invention relates to a novel method of and system for ranging between an acoustic source carried on an unmanned or autonomous undersea mobile vehicle (UUV or AUV) and preferably a plurality of hydrophone receivers remotely deployed from the vehicle in predetermined patterns, generally suspended from sonobuoys equipped with above-the-sea relay radio transmitting antennas, and with time synchronization provided amongst the source and the receivers, wherein the time delay from the transmissions of the source is measured by utilizing special signal processing, enabling range to be measured in close to real time by determining the product of the sound velocity and the measured time delay, and with the process continually and periodically being repeated throughout the duration of the vehicle run.

Abstract: An apparatus designed to float on or in a liquid has at least two buoyant members. The apparatus utilizes relative motion between the buoyant members to generate power, and the buoyant members are coupled to the apparatus in such a manner that surface movement of a fluid that the apparatus is floating in causes relative motion between the buoyant members. The apparatus may be a housing that includes an electrical apparatus within it, with the electrical apparatus being powered directly or indirectly by power generated by the floating apparatus. The apparatus may be a sonobuoy, and may include a sensor array hanging from a floating housing that includes the at least two buoyant members.

Abstract: An apparatus for enabling acousto-optic communication comprising an in-water platform comprising means for emitting an acoustic signal to an acousto-optic interaction zone, an in-air platform comprising the ability for transmitting a first optical interrogation beam, the ability for receiving a portion of the first interrogation beam and a second laser beam formed from the reflection of the first interrogation beam off of the acousto-optic interaction zone, the ability for measuring and outputting a plurality of optical interferences between the portion of the first interrogation beam and the second reflected beam, and a signal converter receiving as input the plurality of optical interferences and outputting an electrical signal representing the received acoustic telemetry signal at the interrogation point at the air-water interface.

Abstract: A buoy system bi-directionally communicates in-air and underwater. A buoy having a shell to float on water has an upper portion in air and a lower portion in water. An array of acoustic transducers which is disposed in the lower portion receives acoustic signals and transmits acoustic signals. A dome-shaped retro-reflective coating on the upper portion is vibrated for retro-reflecting impinging laser illumination as data signals in air. An array of photo-detectors on the upper portion are responsive to impinging laser control signals and/or signals which may be transmitted as acoustic signals in water.

Abstract: An untethered communications buoy system has an untethered buoy freely floating on the surface of water to not compromise the location of the submersible. The submersible has a cavity containing a first data interface member connected to a computer/data-storage that is connected to an acoustic transducer. The untethered buoy has a computer/memory module connected to a radio transceiver and acoustic transceiver. A second data interface member is connected to the computer/memory module and is mounted on the untethered buoy for fitting into the cavity and mating with the first data interface member. A ship is remotely located from the submersible and buoy and has a radio transceiver and an acoustic transceiver. Mating the first and second data interface members permits bidirectional downloading of data between the computer/data-storage and the computer/memory module.

Abstract: A fishing system buoy has a watertight bulbous shell housing an electronic load and with a center of mass located within a lower half of the shell. The load includes sonar operatively coupled via a microprocessor with a radio transmitter that has an upright antenna located in an upper half of the shell. The shell has a keel with an eyelet for tethering a fishing line to the shell. The buoy functions both as a fishing bobber and communications relay station for obtaining and transmitting images of fish swimming beneath the bobber.

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 fishing system buoy has a watertight bulbous shell housing an electronic load and with a center of mass located within a lower half of the shell. The load includes sonar operatively coupled via a microprocessor with a radio transmitter that has an upright antenna located in an upper half of the shell. The shell has a keel with an eyelet for tethering a fishing line to the shell. The buoy functions both as a fishing bobber and communications relay station for obtaining and transmitting images of fish swimming beneath the bobber.

Abstract: An expandable platform for deploying sensors in a medium includes a housing and a structural member disposed inside the housing. A releasable restraint is connected to the structural member. Multiple arms are connected to the structural member. Each arm includes a material memory component that has a natural state, corresponding to a minimum energy state, in an extended configuration. The material memory component is energized by compacting the material memory component so that the arm fits within the housing. The material memory component is restrained in an energized state by the restraint, and naturally transforms toward the extended configurations under its own force when the restraint is released. A flexible cable external to the arms is connected to two or more arms, each at a tip portion of the arm. The tip portion is farthest from the structural member when the material memory component is in the extended configuration. Multiple sensors are connected to the cable.

Abstract: Sonobuoy apparatus which fits into an A sized canister for use in the water environment. The apparatus includes an array of telescopic arms connected by hinges to a housing which contains receiver transducer electronics. An acoustic projector bears against projections on the last arm section of each arm such that it will cause the nested arm sections to extend while dropping through the water. When the canister falls free, an arm deployment arrangement causes the arms to assume a horizontal orientation. These deployed arms carry receive transducers for detecting acoustic echos from a potential target.

Abstract: A reconnaissance sonde to be dropped and erected in an area for wirelessly transmitting data to a data processing apparatus.

Abstract: An acoustic warning assembly capable of being launched from an underwater vehicle while being underwater. The acoustic warning assembly includes an acoustosensitive member for collecting above-surface acoustic signals. The acoustic warning assembly also includes a carrier member launchable from the underwater vehicle, the carrier member is designed to carry the acoustosensitive member above-surface. The acoustic warning assembly also includes a communication medium for communicating between the acoustosensitive member and the underwater vehicle, for transmitting the above-surface acoustic signals collected by the acoustosensitive member to the underwater vehicle.

Abstract: An underwater intelligence gathering weapon system accurately places a weapon underwater and then communicates therewith from other platform(s). The weapon is equipped to maneuver through the air to a destination at the water's surface. A first transceiver, mounted onboard the weapon and coupled to the mine's logic portion, is activated after the weapon is in the water. The first transceiver can send and receive magneto-inductive signals. A second transceiver that sends and receives magneto-inductive signals is remotely located with respect to the first transceiver. Once deployed, the weapon can be controlled from a safe distance and can report any intelligence information collected by onboard sensors.

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 magneto-inductive submarine communication system and buoy provide two-way signal communications between a submerged craft, such as a submarine and remote command station that may be airborne, on the surface, or on land. A buoy released from the submarine and floating on the surface of the ocean and a satellite is included to complete the bidirectional communications. Messages and commands between the submerged craft and the buoy are communicated by magneto-inductive message signals and magneto-inductive command signals in the extremely low frequency (ELF) to very low frequency (VLF) range of less than 3000 Hz. Message and command communications between the buoy and the satellite (or aircraft, or helicopter, or surface ship), and the satellite to the station are transferred via radio frequency (RF) signals or laser emissions.

Abstract: A sonobuoy device for tracking and targeting submarines. The sonobuoy dev comprises a sonobuoy having aft and forward sections interconnected with each other, fin means mounted on the aft section for flight stabilization of the device during travel above water from the platform, separation means responsive to impact of the device with the water upon completion of the travel thereof for separating the sections of the device from each other, payload means within the forward section of the device for listening for an acoustical signal in response to submergence thereof within the water following the separation of the sections of the device, flotation means mounted within the device and inflated in response to the impact with the water for anchoring the payload means and tethering means connecting the flotation means to the payload means for limiting the submergence thereof while anchored by the flotation means to a predetermined depth at which the payload means receives an acoustical signal.

Abstract: A low flow noise sonobuoy suspension system having a surface float, a sussion cable having a compliant portion, a bridle, a hydrophone, a mechanical cable, a terminal weight, and a drogue. The hydrophone is located within the bridle and is attached to the bridle so as to allow the hydrophone to remain roughly vertical if the bridle is tilted. The bridle is located below the surface float and is connected to the surface float by means of the suspension cable. The drogue is located below the bridle and is connected to the bridle by a mechanical cable. The drogue is connected at an attachment point on the mechanical cable such that the relative velocity of the hydrophone is negligible. The terminal weight is also attached to the mechanical cable. By means of this arrangement, both the horizontal motion noise caused by the relative velocity of the hydrophone, and the vertical motion noise caused by the surface waves are reduced.

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 buoyed sensor array communications system comprises multiple sensor syss electrically connected to a signal transmission line which are positioned at predetermined locations along the signal transmission line to form a linear sensor array. Each of the sensor systems generates a data signal in response to receiving an address signal. The system further includes; a processor system electrically connected to the signal transmission line for transmitting address signals to enable any one of the sensor systems at a time in a selectively accessed order and has a data storage memory for storing the data signal from each of the sensor systems as stored data. A radio frequency transmitting system is coupled to the data processor and transmits the stored data at a predetermined time. A negatively buoyant structure connected to the signal transmission line pulls the communications system to the bottom of a body of water upon deployment.

Abstract: A sonobuoy for forming a plurality of virtual vertical arrays, the sonobuoy aving means for receiving and expelling water to cause said sonobuoy automatically to descend and rise in a water environment, whereby to form sequentially a plurality of virtual vertical arrays.

Abstract: An acoustic transponder device includes waterproof housing that accepts a battery pack with a water displacing connection placing the housing and battery pack in communication. The housing carries an electronics package. Both the housing and battery pack can be disposable components, and can be sealed upon manufacture to prevent water ingress.

Abstract: An air deployable, volumetric hydrophone array uses three horizontal booms adiating from a central hub suspended at the array operating depth. Loose lines of hydrophones are hung from pairs of points on the boom structure and hang in arcs approximating catenaries.

Abstract: This invention discloses electronic circuit that can be either embedded in n oceanographic sonobuoy housing or used as stand-alone equipment and which establishes and generates sonar signals of a repetition rate, pulse length, and amplitude pulse shape which are all programmably variable, selectable and determinable. A plurality of predetermined sonar pulse "profiles" are stored in a read only memory (ROM). A particular profile is selected from this memory and this profile is generated point by point at a selected frequency.

Abstract: A marine acoustic detector for use in identifying a characteristic airborne sound pressure field generated by a propeller-driven aircraft including a surface-buoyed resonator chamber tuned to the narrow frequency band of the airborne sound pressure field and having a dimensioned opening formed into a first endplate of the chambver for admitting the airborne sound pressure field. Mounted within the resonator chamber is a transducer circuit comprising a microphone and a pre-amplifier, the microphone functioning to detect the resonating sound pressure field within the chamber and to convert the resonating sound waves into an electrical signal while the pre-amplifier functions to amplify the electrical signal for transmission via a cable to an underwater or surface marine vehicle to undergo signal processing.

Abstract: A sonobuoy system and method for deploying an array of transducers in a substantially horizontal line at a desired depth below the surface of a body of water. The trailing end of the array is deployed first, allowed to descend, and suspended at the desired operating depth. The leading end of the array is then released, allowed to descend slowly, and suspended at the desired operating depth. A drag device attached to the trailing end of the array causes the trailing end of the array to be stretched out away from the leading end, thereby maintaining the array in a substantially horizontal line at the desired depth. The system and method make it possible to deploy horizontal line arrays in a minimum of time and at shallow depths.

Abstract: A buoyed sensor array communications system comprises multiple sensor syss electrically connected to a signal transmission line which are positioned at predetermined locations along the signal transmission line to form a linear sensor array. Each of the sensor systems generates a data signal in response to receiving an address signal. The system further includes; a processor system electrically connected to the signal transmission line for transmitting address signals to enable any one of the sensor systems at a time in a selectively accessed order and has a data storage memory for storing the data signal from each of the sensor systems as stored data. A radio frequency transmitting system is coupled to the data processor and transmits the stored data at a predetermined time. A negatively buoyant structure connected to the signal transmission line pulls the communications system to the bottom of a body of water upon deployment.