Abstract: A hydrophone assembly for deployment on the bottom of a body of water is vided wherein a plurality of hydrophones are mounted in a spaced apart relationship about the circumference of a housing which is designed to hold signal processing electronics. Each hydrophone is constructed to detect a range of frequencies within a defined receive angle that extends outward from the circumference of the housing. A resonance absorbing material is interposed between the housing and the hydrophones to isolate each hydrophone from mechanical resonance. Tilt switches are connected to each hydrophone for automatically and independently selecting hydrophones to participate in the output of the hydrophone assembly based on the orientation of the hydrophones. Selected adjacent hydrophones define a continuous receive angle formed by combining the receive angle associated with each adjacent hydrophone. The continuous receive angle faces upward from the bottom of the water to include an angular portion of the surface.

Abstract: A torpedo seeker head for providing guidance information in three orthogonal axes is provided according to the invention. The torpedo seeker head includes three directional hydrophones, with each directional hydrophone capable of receiving an acoustic signal and generating a signal output therefrom. The three directional hydrophones are aligned with their response axes oriented substantially orthogonally, with any two directional hydrophones and respective axes defining a plane. An omni-directional hydrophone is also provided which measures a phase of a received acoustic signal. The signal outputs from the any two directional hydrophones, in conjunction with the phase from the omni-directional hydrophone are used to calculate a look angle to a target in a plane defined by the any two hydrophones, with the measurement being substantially independent of frequency. The three directional hydrophones yield look angles in three dimensions.

Abstract: The present invention modifies an operational center frequency of a transer array. The array of transducer elements has uniform on-center spacing between adjacent members of the elements having adjacent edges. A controller activates one of a plurality of subsets of the elements that is defined by a pattern throughout the array of activated members of the elements and non-activated members of the elements. The particular pattern in a beamforming direction defines a unique operational center frequency for the array.

Abstract: There is provided an acoustic source especially for use in seismic studies at sea. The acoustic source has a longitudinal axis and sound emitting surfaces adapted to be put into sound emitting movements towards and away from each other by use of a drive unit. The sound emitting surfaces comprise two curved plate members having upper and lower ends essentially symmetrically positioned in relation to the longitudinal axis of the acoustic source, and forming a convex cross section with their respective upper and lower edges converging towards each other. The upper and lower edges of the sound emitting surfaces, respectively, are connected to each other with two corresponding side elements, the side elements each being connected to at least one hinge stretching along at least a part of the length of the source.

Abstract: A method of fabricating one or more arrays of bio-molecule test sites including providing a solution containing bio-molecule probes in contact with the surface of a substrate, using orthogonal acoustic waves to concentrate the bio-molecule probes at a node intersection, bonding the bio-molecule probes on the substrate at the node intersection to form a test site, and removing the solution leaving the bio-molecule probes attached to the surface at the test site. The steps are repeated as often as desired, using different bio-molecule probes, to produce one or more arrays of test sites.

Abstract: A sonar sensor array having a multi-layer tiling arrangement for the indiual elements that increases surface area available for each element while maintaining the inter-element spacing required to avoid spatial aliasing when the received signals are combined to form a sonar beam. The array comprises outer and inner arrays of transducer elements for converting an acoustic signal to an electrical response. The transducer elements of the outer array are positioned such than a grid of isolation spaces separates each of the transducer elements. The transducer elements of the inner array are also positioned such that a grid of isolation spaces separates each one of the transducer elements. The electrical response generated by the transducer elements of the inner and outer arrays are coupled to a beamformer which processes the responses to produce an output signal.

Abstract: Acoustic source, especially for use in seismic studies at sea, with sound emitting surfaces adapted to be put into sound emitting movements toward and away from each other by use of a drive unit in a known manner, in which the sound emitting surfaces comprise two curved plate members essentially symmetrically positioned in relation to the longitudinal axis of the source, forming a convex cross section with their respective upper and lower edges converging towards each other, and the respective upper and lower edges of the sound emitting surfaces are flexibly connected to two corresponding side elements positioned between them, and that the source comprises a rigid frame for supporting the drive unit, comprising at least two rigid slide rods stretching through the side elements, and that rigid covers are mounted on the slide rods, covering at least the whole side elements, thus forming rigid, covering surfaces with a constant distance between the covers.

Abstract: Sonar suspension apparatus comprising a flotation buoy and an underwater sonar array connected to the flotation buoy by a suspension cable, wherein the sonar array comprises a plurality of transducer-carrying elongate members including at least one rigid arm and at least one flexible line.

Abstract: An array system, which provides a unipolar acoustic impulse with a broad spectral response underwater, utilizes a vertical array of airgun or electrical spark sources whose individual peak source strengths are essentially constant over the array length, but whose individual source periods vary with depth. The array of sources produces in each instance a near-unipolar, impulsive signature with a broad pedestal-like spectrum. The system may be used for underwater object location and also for seismic exploration.

Abstract: The invention is a processor based analysis system with appropriate interface that includes multiple fish surrogates that each have a plurality of piezoelectric and triaxial accelerometer sensors for emulating sensory organs of a particular fish. The multiple fish surrogate array is immersed in flowing water intakes of a hydraulic structures such as intakes, intake bypasses, and diversion structures, and natural geological formation such as riffles, shoal areas, and pools. The invention is an interface system for data acquisition analysis and perspective display of acoustic and fluid dynamic data in or near these hydraulic structures and/or natural formations. To accomplish this, multiple sensors in each of the fish-shaped surrogate physical enclosures that form the array are deployed at the same time to describe a fish's aquatic environment at the hydraulic structure location.

Abstract: The invention relates to a device for monitoring the absence of motionless bodies in a swimming pool. Two cameras (1) provide for the permanent imaging of the bottom of the swimming pool. These images are first digitized and then processed by a computer. The superimposition of the two information permits analysis of substantially the entire the surface of the swimming pool in order to determine if a portion is masked by an obstacle. When such obstacle is detected, the duration of the presence of each masked pixel is analyzed. After a certain time delay, and for a minimum number of neighboring pixels, an alarm is generated.

Abstract: A sonar array uses multiple acoustically transparent layers. One layer is a lanar array of acoustic sensors that is substantially acoustically transparent. Another layer is an acoustically transparent wiring assembly that provides electrical connection to each acoustic sensor. A third acoustically transparent layer is a planar array of signal processing circuits coupled to the wiring assembly for processing electrical signals generated by the acoustic sensors. Each signal processing circuit resides within an area that is in geometric correspondence with a respective one acoustic sensor. Each signal processing circuit can include a preamplifier, an analog-to-digital converter and a digital multiplexer.

Abstract: A method and system are provided for frequency filtering compressional wave nergy. An elastic cylinder is filled with a fluid that is selected based on a fluid density .rho..sub.i and a dilatational wave phase velocity c.sub.i thereof. When the elastic cylinder so-filled is subjected to a compressional wave propagating in a fluid environment, a first radial resonance frequency of the elastic cylinder is controlled by the fluid density .rho..sub.i and the dilatational wave phase velocity c.sub.i. Further tuning of the first radial resonance frequency can be achieved by adjusting the radial wall thickness of the elastic cylinder.

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: There is provided a two-dimensional array for use in an acoustic imaging system which comprises a plurality of transducer segments each having a trace for exciting an electrode on each of the transducer segments, the trace and the electrode being formed of the same material. The two-dimensional array disclosed is capable of imaging deeper in the human body at higher frequencies and provides more reliable lead attachments to the respective segments forming the array. Methods of manufacturing the two-dimensional array are further provided.

Abstract: A retractable sensor array system is used to provide a large aperture sen array, such as a sonar array, that receives acoustic energy in a deployment medium. The retractable sensor array system includes one or more sensor array sheets having one or more sensors and a sensor array positioning mechanism for deploying and retracting the sensor array sheet from a platform, such as a ship, submarine, aircraft, space vehicle or medical device. The sensor array positioning mechanism preferably includes a motor that automatically and selectively deploys and retracts the one or more sensor array sheets by rolling and unrolling the sensor array sheets. The retractable sensor array system allows the one or more sensor array sheets to be deployed from various locations on a platform and also in various directions from the platform depending upon the desired usage, platform orientation, position and deployment medium conditions.

Abstract: An omnidirectional ultrasonic microprobe hydrophone is disclosed. Applicans include underwater mine detection, explosive shock testing, high wave number measurements, medical imaging, and therapeutic systems. The apparatus includes at least two lead zirconate titanate (PZT) pressure sensing elements having a plurality of columnar voids formed therein. The pressure sensing elements are deposited on a metallic or nonmetallic substrate which provides mechanical support for the microprobe hydrophone. Electrical connection to the pressure sensing elements is made by deposition of conductors and insulators on the substrate material. Wire bonds are used to attach wire leads for connection to a supporting structure containing a preamplifier. Line arrays and planar arrays of microprobe hydrophone elements are also disclosed.

Abstract: Disclosed is a sonar system comprising a platform, axially extendable supts projecting from the platform, a flexible cable array deployed from the platform means through said support means, and an acoustic detector connected to the flexible cable. By increasing the physical aperture of the sonar system, performance is enhanced.

Abstract: An acoustic receiver array assembly includes an underwater vehicle having a ase portion and an acoustic receiver portion. The base portion is provided with a rigid boundary wall defining a first largest diameter. The receiver portion is provided with a flexible boundary wall expandable from a generally cylindrical configuration of no more than the first diameter to an expanded configuration of a second diameter substantially larger than the first diameter, the receiver portion defining a chamber. Expansion means is disposed in the chamber and is operable to expand the receiver portion boundary wall to the second diameter. Acoustic receivers are mounted in the receiver portion and provide an acoustic receiver array which expands commensurately with the expansion of the receiver portion boundary wall.

Abstract: A sonar antenna with transducers symmetrically distributed along an axis (fore/aft axis) and a perpendicular axis (starboard/port axis) in a plane on a circular base. Placement and polarities of the transducers, along with a phase and sequence of feeding two distinct frequencies to the transducers create four emission lobes inclined at 30 degrees one emission lobe with respect to each axis. Summation of reception signals (echos) from selected transducers based on frequency and accounting for time allow for the determination of fore/aft and starboard/port reception signals from which a velocity of the antenna or a vehicle attached to the antenna can be calculated.

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: An acoustic receiver assembly includes a first tubular body and a multiplty of first acoustic receivers disposed on an outer surface of the first body. A second tubular body is slidably movable in the first body and is extendible therefrom. A multiplicity of second acoustic receivers is disposed on an outer surface of the second body, the second acoustic receivers being receivable by the first body.

Abstract: A volumetric/planar array structure for detection of low frequency active pulses in shallow water. The structure is such that the array can be repeatedly deployed and retrieved. The invention utilizes folding array arms that are deployed at a pre-selected depth using only gravity once the release mechanism for deployment has been initiated. Rigid vertical support rods attach to all array levels preventing rotation down below the desired horizontal position during operation. Retraction of array arms for array structure retrieval is initiated by activating an electronic underwater release mechanism which then allows compliant rubber members to pull array arms in place. Once the array arms are in place, they are protected by a skid/crash cage fixture and the array structure is then ready for retrieval.

Abstract: Acoustic source assembly for offshore seismic exploration, comprising at least one active vibration transducer (1) adapted to be excited by a sweep signal within a desired frequency range. At least one further and passive vibration transducer (2,3) is positioned at such small spacing (B) between the transducers that interaction therebetween provides for a relative enhancement of the frequency response of the whole source assembly at low frequencies.

Abstract: This invention describes a methodology to image features using an array of multiple piezo-electric elements which employs the selective use of mechanical and electronic beam focusing, electronic beam steering and amplitude shading to increase resolution and overcome side lobe effects. This invention introduces a novel signal reconstruction technique utilizing independent array element transmission and reception, creating focusing and beam steering. Application of the methodology can be used in wireline, measurement while drilling, pipe and pipeline and medical applications. Applications include, but are not limited to Bore hole Caliper, Bore hole Geometry, Bore hole Imaging, Casing Inspection, Cement Evaluation and Volumetric Scanning Applications (e.g. Fluid, Behind Casing and Open Hole). The configuration of the transducer array is preferably cylindrical, but may be conical, biconical, convex, concave or may take the form of a number of suitable geometric configurations.

Abstract: An electrostatic ultrasonic transducer formed on a semiconductor substrate by micro-machining wherein the transducer includes a silicon nitride membrane supported above the surface of the substrate by insulating supports; and the substrate and membrane define the electrodes of the transducer.

Abstract: An underwater vehicle sonar system has sonar sensors provided in arms to plement a nose mounted array. The arms are capable of use in an extended position to provide a large diameter sonar array offering improved image resolution in the forward direction. In the extended position the arms also are capable of acting as active hydrodynamic control surfaces. Additionally, the arms can be used in a stowed position to provide a linear array for side viewing.

Abstract: A transducer array according to the invention includes forty-two acoustic transducers for use in a fluid medium, with each of the transducers having maximum lateral dimensions of less than one acoustic wavelength in the medium, whereby the transducers themselves tend to radiate isotropically. The elements of the array are located at the vertices of an regular geodesic two-frequency icosahedron. The transducer array also includes a driver or a receiver, or both, and arrangements for coupling them to the array elements. A switching circuit can couple the array elements alternately to the driver or receiver, depending upon the operating mode. A conventional delay controller is coupled to the acoustic transducers, for controlling an acoustic beam formed by the array. In a particular embodiment of the invention, the array is operated at frequencies selected so that the inter-transducer spacing of any two mutually adjacent transducers does not exceed 2.lambda./3, and is not less than .lambda./3.

Abstract: A chain of elongate components (10, 20) are connected end-to-end. Each component (e.g. 10) comprises a sheath (1) closed at its ends filled with a dielectric liquid (e.g. kerosene). Sound detectors are located in the liquid as are electric conductors for conveying signals therefrom. The ends are closed by means including an electric connector. At least one of a pair of mating end portions includes a valve (14, 24) which releases the dielectric liquid from inside the sheath into the interstices between the mated pair. A bleed screw can be used to ensure no air remains. This arrangement minimises pressure differentials around the join between two adjacent elongate components and facilitates use of the chain at great depths.

Abstract: A composite hydrophone array assembly is made from a compliant mandrel such s a hollow tube and at least one wrap of piezoelectric film adhered to the compliant hollow tube at a plurality of locations thereon. Each location defines a composite hydrophone channel. The centers of adjacent hydrophone channels are separated along the length of the compliant hollow tube. To shade a hydrophone channel, the wall thickness of the hollow tube can be varied along its length, the circumferential area of coverage of the wraps of piezoelectric film can be varied along their length, the longitudinal lengths of the wraps of piezoelectric film are varied, or a combination of these approaches can be used. Unwanted noise is rejected by eliminating hydrophone channel grating lobes and overlapping portions of the wraps of piezoelectric film of the adjacent hydrophone channels to create a wavenumber response for the composite hydrophone array that significantly reduces array grating lobes.

Abstract: In a digital ultrasound imaging system, artifacts due to spurious ultrasound reflections from a highly reflective object outside the region of interest are reduced in magnitude by apparatus included in the beamforming system of the digital imaging system. A null is formed in a specified direction in the ultrasound beam patterns by perturbing the time delay on each receive channel. After estimating the direction of the highly reflective, interfering object and computing a time delay perturbation using a very fast algorithm, a null approximately 10 dB deep is introduced into each beam in the direction of the interfering object. This null reduces the magnitude of artifacts in the image, thereby providing image enhancement.

Abstract: A method for determining a unique signal representing the earth's response between a transmitter and receivers when conducting a seismic survey involves the steps of receiving a seismic signal set that comprises a plurality of different output frequency signals having known amplitude and phase characteristics, selectively combining the different output frequency signals to form the unique signal, and recording values of amplitude, phase, and frequency of the unigue signal. A method of conducting a modulated seismic survey involves the steps of providing seismic sensors capable of receiving a modulated seismic signal comprised of different frequency signals, transmitting modulated seismic energy information into the earth, and recording indications of reflected and refracted seismic waves sensed by the seismic sensors in response to transmission of the modulated seismic energy information into the earth.

Abstract: An acoustic transducer is constructed as a stacked configuration of multiyer transducer elements separated from one another by an electrical insulating material. Each multi-layer transducer element has a layer of acoustically transparent electro-acoustic transducer material having opposing planar surfaces with electrically conductive material deposited thereon. For each multi-layer transducer element, the electrically conductive material is formed into parallel strips electrically isolated from one another on at least one of each element's opposing planar surfaces. The parallel strips associated with each multi-layer transducer element have a unique angular orientation.

Abstract: Acoustic signals and hydraulic pressure variations which influence fish bvior in bodies of water are measured and recorded by apparatus simulating a fish immersed in water, fitted with piezoelectric transducers and connected by wiring to remote amplifying and recording means. Such data are correlated with fish behavior for the purpose of developing methods of diverting fish from such areas of danger as the intake piping of hydroelectric power generating turbines and pumping stations.

Abstract: The invention relates to a device for locating noise emitters with an antenna comprising passive sensors. In a preferred variant, the antenna consists of N acoustic buoys each comprising a pair of hydrophone dipoles exhibiting a double-eight directivity diagram. Each buoy comprises a compass providing a signal K.sub.n representing the heading relative to magnetic North. The pairs of signals (a.sub.1 -b.sub.1 to a.sub.N -b.sub.N) are subjected to a rotation by the angle K.sub.n. The signals are next digitized and the number P of noise emitters estimated. The locating of these noise emitters can be performed according to two variants (8, 9).

Abstract: A vessel, such as a submarine, has onboard sensor processing, display, and omputer control capability for an array of sensors deployed from the vessel. The array includes a plurality of cables containing numerous sensors on each cable. The cables are suspended vertically from a housing on reels that provide a convenient means for deployment and recovery of the array. A submersible means at the lower end of the cables includes active transducers, propulsion devices and control surfaces for orienting and driving the structure so as to maintain a speed and direction for this structure corresponding to that of the vessel.

Abstract: A fiber optic array having a plurality of subarrays of optical sensors, the subarrays being spaced apart along and optically connected to input and output buses through associated input and output optically actuated optical switches in series in the input and output buses. First and second light signal pulse trains are applied to one and other ends of the input bus and a third light signal pulse train is applied to one end of the output bus. The input switches are sequentially responsive to each first light signal pulse on the input bus for passing to an associated subarray a pulse of second light signal that is simultaneously present at that input switch such that second light signal pulses of the same magnitude are applied to each subarray. Associated output switches are sequentially responsive to third light signal pulses for passing trains of second light signal pulses from the arrays onto the output bus and to processing equipment.

Abstract: A tunable ultrasonic probe includes a body of a first piezoelectric material acoustically coupled in series with a body of a second piezoelectric material. The second piezoelectric material has a Curie temperature that is substantially different than that of the first piezoelectric material. Preferably, the first piezoelectric material is a conventional piezoelectric ceramic, such as lead zirconate titanate, while the second piezoelectric material is a relaxor ferroelectric ceramic, such as lead magnesium niobate. At an operating temperature of the probe, the first piezoelectric material has a fixed polarization. In contrast, the second piezoelectric material has a polarization that is variable relative to the fixed polarization of the first piezoelectric material. A preferred novel arrangement of electrodes electrically couples the bodies in parallel with one another. An oscillating voltage for exciting the acoustic signals in the probe is coupled with the electrodes.

Abstract: A decoupling ring provided on the front annular face of the nose shell of a craft, surrounding the sonar array. This ring decouples the vibration in the nose shell from the fluid path. The decoupling ring is constructed of one or more mass elements on one or more compliance elements. The individual compliance elements are preferably vibrationally speaking springs and the mass elements are preferably metal segments which form a mass-spring system. The dimensions and characteristics of the mass and compliance rings are chosen to have a fundamental resonant frequency well below the sonar frequency range of interest, thus acting as a low pass filter. When the vibrational energy has a frequency above the resonant frequency of the mass spring system, the vibrational energy is attenuated effectively. The low frequency resonance of the decoupling ring is obtained by using a large mass and a large compliance in the mass and compliance elements, respectively.

Abstract: An array plate for use in an underwater craft. The craft having an array of sonar elements which has a selected range of operating frequencies. The array plate having at least one layer of material in which the layer(s) of material are designed to have selected natural frequencies of vibration throughout the range of sonar operating frequencies. The natural frequencies resulting in standing waves having selected wavelengths that develop along the layer(s) of material. The sonar elements are mounted upon the layer(s) of material such that adjacent sonar elements are spaced apart a distance of one half the average wavelength of the standing waves.

Abstract: A curvilinear wideband, projected derivative-matched continuous aperture acoustic transducer includes a first curvilinear sensor having a predetermined spatial shading which is constrained to zero at its ends and has amplitude continuity between its ends; and a second curvilinear sensor area having a spatial shading which is the projected spatial derivative of the spatial shading of said first area and which has a discontinuous amplitude at its ends; the first and second spatially shaded areas being superimposed and coextensive along the sensing axis.

Abstract: A method for reconnection and connection of sensor groups, especially hydrophone groups or channels in a seismic cable, where the active sections in the seismic cable are connected with electronic modules or one another via connector plugs, is based on the principle that a specific number of hydrophone groups are connected symmetrically on each side of each electronic module. The number of connected hydrophone groups on each side is identical and constitutes at least one respective active section. A summation of a set of hydrophone groups in a section is performed automatically by connecting this section with another section or by connecting a respective section and the electronic module.

Abstract: A flexible sheet in which miniaturized operational components, such as hyphones, solid-state preamplifiers and wires, can be embedded or molded into a flexible carrier. The sheet can also be built up of layers, such as an acoustic isolation layer. The sheet is affixed to a mounting surface by adhesives or otherwise and assumes the shape of the mounting surface so that conformal transducer arrays, for example, are easily formed.

Abstract: A wideband, derivative-matched, continuous aperture acoustic transducer includes a first sensor area having a predetermined spatial shading and a second sensor area having a spatial shading which is the spatial derivative of the spatial shading of the first area; the first and second spatial shaded areas are superimposed and co-extensive along the sensing axis.

Abstract: Sonars provided with an acoustically transparent antenna. In a sonar comprising deployable arms (2) provided with columns (4) distributed on a cylindrical surface, the invention provides for the doubling of said columns (7) situated at a small distance from the first columns and for the association of signals from hydrophones mounted in the columns so as to obtain for each pair of columns a cardioid characteristic simulating a baffled antenna. The invention makes possible the suppression of the rear lobe of an acoustically transparent antenna.

Abstract: A side looking sonar transducer having a plurality of active elements forming an elongated active radiating, or receiving surface wherein the active elements at the ends of the transducer have a lesser depression angle than the active elements at the middle. This arrangement provides an energy distribution which allows for a greater depth of focus.

Abstract: A fiber optic array having a plurality of subarrays of optical sensors, the subarrays being spaced apart along and optically connected to input and output buses through associated input and output optically actuated optical switches in series in the input and output buses. First and second light signal pulse trains are applied to one and other ends of the input bus and a third light signal pulse train is applied to one end of the output bus. The input switches are sequentially responsive to each first light signal pulse on the input bus for passing to an associated subarray a pulse of second light signal that is simultaneously present at that input switch such that second light signal pulses of the same magnitude are applied to each subarray. Associated output switches are sequentially responsive to third light signal pulses for passing trains of second light signal pulses from the arrays onto the output bus and to processing equipment.

Abstract: A sonar array which is operable at a broad range of frequencies, has a high free-field voltage sensitivity and is operable at high hydrostatic pressures. The array includes sensor elements made of a piezoelectric material, a backing plate which supports the sensor elements, a dielectric-elastic insulator positioned between the sensor elements and the backing plate, and backing blocks corresponding, respectively, to the sensor elements, each backing block positioned between a corresponding sensor element and the insulator. The sensor elements are arranged in staves, the staves forming four separate quadrants, the sensor elements in each stave being arranged in parallel and series combinations, so that the sonar array is operable between a frequency range of 10 kHz to above 100 kHz, each stave has a free-field voltage sensitivity of -186 dB re 1V/.mu.

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.

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.