Abstract: A sensor arrangement is provided for use in the seismic investigation of geological formations below the seabed. A plurality of sensor nodes (20) are provided and are positioned gfor deployment on the seabed to collect pressure waves and shear waves from the geological formations and to transfer seismic data to a surface receiver. Each sensor node (20) may include a cylindrical structure (22), which is intended to penetrate downwardly into the seabed. At least one, preferably three, geophones (30-32) are positioned in connection with this structure (22). An advantageous method for operating a seismic mapping system with sensor arrangements orderly deployed on the seabed records data concerning system behavior and seismic data. This data may be further processed separately.

Abstract: An ultrasonic sensor has an intermediate connection member for having electrical connection between an ultrasonic transducer and a circuit board. A connection pin of the transducer supported by the intermediate connection member is prevented from being damaged when an excessive pressing force on the transducer pushes the transducer into a case, because a deformation of the connection member releases the force without damaging the connection between the transducer and the circuit board.

Abstract: A marine seismic exploration method and system comprised of continuous recording, self-contained ocean bottom pods characterized by low profile casings. An external bumper is provided to promote ocean bottom coupling and prevent fishing net entrapment. Pods are tethered together with flexible, non-rigid, non-conducting cable used to control pod deployment. Pods are deployed and retrieved from a boat deck configured to have a storage system and a handling system to attach pods to cable on-the-fly. The storage system is a juke box configuration of slots wherein individual pods are randomly stored in the slots to permit data extraction, charging, testing and synchronizing without opening the pods. A pod may include an inertial navigation system to determine ocean floor location and a rubidium clock for timing. The system includes mathematical gimballing. The cable may include shear couplings designed to automatically shear apart if a certain level of cable tension is reached.

Abstract: A resonator device comprises a plurality of transducers fitted and spatially aligned on the four prongs of two tuning forks, with vibrating masses, placed side-by-side with the four prongs arranged at 90° angles one from the other in a clockwise or anticlockwise direction, the distance between the individual prongs, their dimensions, shapes and masses, producing mechanical vibrations and resonances at predetermined frequencies.

Abstract: A housing for a seismic sensing element (3) for use on the earth's surface comprises connecting means (5) for connecting the housing (3) to a support cable (2) so as to allow relative movement between the sensor housing (3) and the cable (2). This de-couples the sensor housing from the support cable, and improves the fidelity of the sensor. The connecting means (5) preferably comprises resilient connecting elements, to prevent the transmission of vibrations between the support cable and the sensor housing. The sensor housing (3) preferably has a flat base (1), so that there is good coupling between the sensor housing and the earth. Alternatively, the sensor housing can be fitted with a base member ((24a, 24b, 24c) that has at least one flat face (26, 26a, 26b, 26c).

Abstract: A seismic data collection unit having multiple separate geophones/geophone packages positioned in a housing wherein the geophones are offset from a vertical axis so that summing of the geophones' respective outputs minimizes certain noise in the unit's output. Specifically, the offset geophones are physically positioned or mathematically configured so as to be symmetrical about a selected vertical axis in order to cancel out certain noise in a seismic signal. The particular placement of the geophones within the housing is preferably selected so that the vertical axis around which the geophones are positioned passes through the center of gravity of the unit.

Abstract: A vessel hull transducer modular mounting system enables transducers to be replaced and upgraded without necessitating the further modification of the hull and thus not necessitating the dry-docking of the vessel. A further feature includes the ability to reduce and dampen acoustic shock impact on the transducer. Another feature includes the ability to extend and retract the transducer which can operate in bottom scan, forward looking, side scan, searchlight, and sweep modes.

Abstract: The present invention provides an apparatus and method for sensing subsurface data. One embodiment of the invention comprises a shuttle attached to a conveyance where the conveyance and shuttle are adapted to be spooled downhole into a borehole for sensing seismic data. The shuttle contains a sensor package that is preferably acoustically isolated in the shuttle. The sensor package includes a sensor array and a magnet clamp. A sensor section can contain several shuttles, each shuttle containing at least one sensor. In one embodiment, the sensor can be a fiber optic sensor. The magnet clamp is operable to controllably clamp and acoustically couple together the sensor package, the shuttle, and the adjacent structure which is typically the borehole casing. The magnet clamp is likewise operable to unclamp and uncouple the shuttle from the adjacent structure so as to be retracted uphole for subsequent use.

Abstract: A guard is provided that protects sonar transducers attached to trolling motors from damage due to impact with underwater debris. The protective guard is mounted on the trolling motor in front of the sonar transducer.

Abstract: In the present invention, a seismic receiver contains an onboard digitizer that samples and converts a signal from detected seismic energy into the digital domain. The receiver contains an analog to digital converter, a transmission circuitry, and a link to the seismic detection circuitry. The signal from the seismic detection circuitry is converted into a digital signal, which is then relayed to the data recorder. These components are all resident to the receiver itself. Additional control circuitry is employed to provide clocking and testing functions. These receivers communicate with one another, and provide sampled seismic data on an individual basis. The components may be prepared on a PCB and put inside the receiver cap. The PCB may be flexible in nature, as to provide a maximum of surface mounted components in the smallest amount of space.

Abstract: The invention relates to a source block with a downhole seismic source for use in seismic acquisition during production, comprising: a device for locking the block in a first position spaced from the well casing, a device for releasing the locking device, a device for urging the source block against the casing. The source block is characterized by comprising, a fluid circuit for controlling the operation of the locking and releasing devices, this fluid circuit comprising a rupture disc.

Abstract: A sonde and an apparatus for the deployment thereof against a well casing is described, the sonde comprising a resilient C-shaped member (22) and at least one sensor (23).

Abstract: A combination stabilizer system and cylindrical-shaped undersea package improves validity of data collected from ambient sea by orienting the package in an upright attitude and eliminating motion or rocking due to wave action and/or sea currents. An outrigger base assembly has a flat base surface to rest on the sea floor and is provided with upper surfaces having semi-circular cross-sectional configurations to contiguously fit adjacent to round outer contours of an undersea package. The outrigger base assembly also has laterally extending outrigger portions extending the flat base surface for increased stability. First and second case clamps have curved surfaces with semi-circular cross-sectional configurations that extend above the outrigger base assembly. The first and second clamps clamp the curved surfaces and upper surfaces onto the round contours and secure the undersea package in an upright orientation.

Abstract: A seismic exploration method and unit comprised of continuous recording, self-contained wireless seismometer units or pods. The self-contained unit may include a tilt meter, a compass and a mechanically gimbaled clock platform. Upon retrieval, seismic data recorded by the unit can be extracted and the unit can be charged, tested, re-synchronized, and operation can be re-initiated without the need to open the unit's case. The unit may include an additional geophone to mechanically vibrate the unit to gauge the degree of coupling between the unit and the earth. The unit may correct seismic data for the effects of crystal aging arising from the clock. Deployment location of the unit may be determined tracking linear and angular acceleration from an initial position. The unit may utilize multiple geophones angularly oriented to one another in order to redundantly measure seismic activity in a particular plane.

Abstract: A structure and method for constructing a non-oil-filled towed array providing a single cable entry point for each channel regardless of the number of hydrophones used to make up a hydrophone group or array is described. The method and apparatus enables uniform buoyancy of the hydrophone array and the primary cable around which the hydrophone array is wound. Uniform buoyancy is achieved through the addition of hollow micro-spheres into a Reaction Injection Molded (RIM) polyurethane material used to mold the hydrophones. Additional buoyancy may be desired adjacent heavier cable sections where connectors and telemetry modules are located. An embodiment enables precise adjustment of hydrophone cable buoyancy by providing precise adjustment of the concentration of hollow glass micro-spheres in areas where more or less buoyancy is desired.

Abstract: A encapsulation method of an acoustic sensor module and a resultant lightweight watertight acoustic sensor module for use in towed array retrieval systems. In the method, a composite is cast to encapsulate the support between end plates of the module, an exterior of a passage tube in which the array is retrieved, transducers positioned on the tube exterior and supporting telemetry lines for the transducers. The components, listed previously, are cast into a block of the cured composite such that the arrangement of the components is fixed. Residual composite emitting from an aperture of an end plate allows a conductor for the telemetry lines to be potted into the composite with an end of the conductor free from the composite thereby allowing connection to an external controller or generator.

Abstract: A waveguide system for radiating sound waves. The system includes a low loss waveguide for transmitting sound waves, having walls are tapered so that said crosssectional area of the exit end is less than the cross-sectional area of the inlet end. In a second aspect of the invention, a waveguide for radiating sound waves, has segments of length approximately equal to A ⁡ ( y ) = A inlet ⁡ [ 1 - 2 ⁢ Y B + ( Y B ) 2 ] where l is the effective length of said waveguide and n is a positive integer.

Abstract: An underwater acoustic receiver sensor is disclosed that measure up to seven (7) quantities of acoustic field at a collocated point. The quantities measured by the acoustic receiver sensor are acoustic pressure, three orthogonal components of acoustic particle acceleration and three spatial gradients of the acceleration vector. These quantities are appropriately combined and provides for improved directivity of the acoustic receiver sensor.

Abstract: An structure and method for constructing a non-oil-filled towed array providing a single cable entry point for each channel regardless of the number of hydrophones used to make up a hydrophone group or array. The method and apparatus enables uniform buoyancy of the hydrophone array and the primary cable around which the hydrophone array is wound. Uniform buoyancy is achieved through the selective addition of hollow micro-spheres into a Reaction Injection Molded (RIM) polyurethane material used to mold the hydrophones. For example, additional buoyancy may be desired adjacent heavier cable sections where connectors and telemetry modules are located. The preferred method and apparatus enables precise adjustment of hydrophone cable buoyancy by providing precise adjustment of the concentration of hollow glass microspheres in areas where more or less buoyancy is desired.

Abstract: A case 1 is formed of thermoplastic resin, and includes an upper case 11 and a lower case 21. The case 1 accommodates a pole piece 31, a coil 41, a magnet 51, a diaphragm 61, and so on. The pole piece 31 includes an core 32 and a base 33, and placed on the lower case 21. There are integrally formed on an upper face of the lower case 21, a wall 22 for defining a mounting position of the pole piece 31, a projection 23 for preventing a conductive wire 42 drawn our from the coil 41 from getting in touch with the base 33, and a bobbin part 24 for the conductive wire 42 to be wound therearound. A height of the projection 23 is set at an equal or larger value to or than a height of a surface of the base 33, and a contact of the conductive wire 42 with the base 33 can be avoided by the projection 23.

Abstract: In an ultrasonic sensor, including a housing having a plug connector, an ultrasonic converter, and a circuit board, the housing is divided into a support and a hood enclosing the support. The support carries the circuit board, the plug connector, and the ultrasonic converter.

Abstract: A method is provided to estimate acoustic impacts to marine animals within a chosen area. The method begins with data collection on types of acoustic sources to be modeled, animal assemblages in the chosen area, environmental characteristics of the area and on relevant environmental regulations. An acoustic model, appropriate for the chosen area and its environmental characteristics, is then selected and generates a source footprint of all sources to be located at the site. The marine animal distribution is then overlaid onto the acoustic propagation at the site. The marine animal distribution is time-weighted to correspond with the proposed acoustic source usage, as well as short term and seasonal marine animal behavior patterns. The total number of impacted marine animals is then calculated. Impacts are calculated by species, source, scenario and season. The calculated number is then rounded upwards to the next whole individual, pod, or group, depending on the animals' behavior patterns.

Abstract: A structure and method for constructing a non-oil-filled towed array providing a single cable entry point for each channel irregardless of the number of hydrophones used to make up a hydrophone group or array is described. The method and apparatus enables uniform buoyancy of the hydrophone array and the primary cable around which the hydrophone array is wound. Uniform buoyancy is achieved through the addition of hollow micro-spheres into a Reaction Injection Molded (RIM) polyurethane material used to mold the hydrophones. Additional buoyancy may be desired adjacent heavier cable sections where connectors and telemetry modules are located. An embodiment enables precise adjustment of hydrophone cable buoyancy by providing precise adjustment of the concentration of hollow glass micro-spheres in areas where more or less buoyancy is desired.

Abstract: A geophone including conductive terminals positioned on opposite sides of the geophone housing. The geophone includes a pair of coils resiliently mounted within the geophone housing and a magnet. A first end plate, a first spring, and a first coil support provide a first end of the electrically conductive path. A second end plate, a second spring, and a second coil support provide a second end of the electrically conductive path. The first and second end of the electrically conductive path are electrically insulated from each and the geophone housing. Providing one or more remaining components with electrically non-conductive surfaces provides electrical insulation.

Abstract: An acoustic sensor may include a base, a diaphragm, and a piezoelectric film. A cup may be disposed around the sensor. A filling material may be injected inside the cup and around the sensor. An end cap may be placed at an end of the cup to enclose the filling material within the cup. The cup may include longitudinal fibers disposed in an adhesive matrix. The acoustic sensor and the cup may be encapsulated in a molding material using a reaction injection molding (RIM) process to form a sensor section. Buoyant sections may be formed between sensor sections on a strain member. Buoyant sections may be formed by encapsulating a portion of the strain member in a buoyant molding material using a RIM process. be The strain member, the sensor sections, and the buoyant sections may be joined to form an array.

Abstract: An apparatus for protecting sensing devices disposed on an outer surface of a pipe is provided. The apparatus includes a housing and a plurality of bumpers. The housing is attached to the outer surface of the pipe. The bumpers are attached to one of the outer surface of the pipe or the housing. Each bumper includes a post and a bumper pad. The bumpers are enclosed within the region formed between the housing and the pipe.

Abstract: A shield for a sonar transducer secured by a flexible clamping band to the bottom of a trolling motor housing. The shield includes a box-like body sized to receive a transducer. The body further includes an open top for flush positioning against a trolling motor housing and an open bottom through which sonar transmissions from the transducer may pass. The body has a pair of slots adjacent its open top for the passage of a clamping band of a hose clamp.

Abstract: A method of and an apparatus for mounting seismic vibration sensors to a cable designed for use offshore, such that the sensors are optimally coupled to the ocean floor through all cylindrical rotations when the cable has reached the bottom after being slipped over the transom of a deployment vessel. Said coupling is accomplished without the use of a sub-surface robotic vessel to force the sensors into a particular orientation. The housing for the sensors is adapted to endure and minimize the impact on the host cable of the mechanical extremes the system is subjected to in the process of the conventional deployment and retrieval methods.

Abstract: A method for the study of elastic wave phenomena in the ground, where the detection of said phenomena is carried out with the use of at least a geophone comprising at least a couple of transducers (20, 21; 37, 38), each transducer (20, 21; 37, 38) being apt to detect horizontally polarized shear waves, represented by SH signals, and compression waves, represented by P signals.

Abstract: A seismic cable (1) including a plurality of electrical/optical elements (5) which are arranged to be interconnected with a number of seismic sensor devices (24) arranged at intervals along the cable and installed in a housing (15) integrated in the cable (1). The sensor housing (15) is centrally arranged in the cable (1) and interconnected with a central strength element (2). The electrical/optical elements (5) are arranged over and around the central element (2) and over the housing (15).

Abstract: The design and method of fabrication for an acoustic sensor module for mounting on the hull of a submarine or surface ship is disclosed. The design involves the use of molded alignment structures within a two part rubber shell to reduce tooling requirements and eliminate a significant amount of assembly labor in fabricating hull mounted sonar arrays.

Abstract: A geophone with mounted connectors includes a body, a plurality of removable cable connectors, and a cap. The body includes an opening defining a cavity, a first circuit board positioned in the cavity, and a seismic detector positioned in the cavity operably coupled to the first circuit board. The cable connectors are positioned in the cavity above the first circuit board. The cap is coupled to the body and includes a second printed circuit board operably coupled to the cable connectors and the first circuit board.

Abstract: Acoustic intensity is measured by a submerged probe consisting of two passive geophones mounted in spaced relationship with their sensing axes aligned. The geophones are connected through a cable to a remote spectrum analyzer in which acoustic intensity is computed from the velocity gradient between the two geophones. The exclusive use of geophones, which inherently have low impedance outputs, eliminates the need for preamplification in the probe. The geophones are mounted inside an acoustically transparent, thin rubber shell, which reduces the effects of noise due to flow.

Abstract: An arcuate or flat ferroelectric sensor is incorporated in a seismic streamer. The structure comprises two half-cylinders which are mounted together around a cable. The half-cylinders are coupled together by bolts or pins or any other appropriate means. Each half-cylinder defines a well into which a sensor is mounted. With the sensor in place, the structure is covered over with a sound-transparent material to receive an acoustic signal into the sensor. Electrical leads from the sensor are directed through ports in the half-cylinders, and the leads are connected together to provide a composite sensed signal to the cable in analog form. The sensor in each half-cylinder is a single element hydrophone that, when connected to a sensor in a complementary half cylinder in series or in parallel, forms an acceleration cancelling hydrophone.

Abstract: A molded protective body member for seismic cable hydrophone and geophone sensors and their cable splice connections from underwater obstructions and pay-out and retrieval apparatus. The body member is a one piece polymeric member having interior cavities, risers and apertures. When in use, the body member is folded longitudinally in half around the seismic cable at a hydrophone or geophone splice joint and secured in place with recessable molded straps having threaded fasteners passing through each of the body halves thus clamping the body to the cable. At least one interior diametrical cavity is provided consistent with the type seismic cable sensor used. With the sensor and its associated cable and connector positioned within the protective body member, tie wraps are threaded through apertures along and adjacent the longitudinal edges of each half thus closing the interior of the body member. Cavities are also provided internally for placing lead weights.

Abstract: An assembly module provides well-organized optical fiber component attachment features and convenient fiber routing areas for assembling and containing a fiber optic device such a telemetry module. The module comprises a first substrate having a first side and a second side. The first side includes a plurality of sidewalls and a recessed floor surface bounded by the sidewalls. Some of the sidewalls have a cavities formed therein. A plurality of channels extend from the ends of the cavities. A plurality of projections extend from the sidewalls over selected portions of the floor surface such that a lower edge of each projection is spaced apart from the floor surface. Optical fiber components (couplers, splices, etc.) may be mounted in the cavities, and optical fibers are routed to and from the optical fiber components on regions between the sidewalls and through the channels.

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: An ultrasonic transducer (10) includes a housing (12) having a main section (14) and a base section (16). Retainer elements (20) on the main and base sections (14 and 16) of the housing (12) are engageable only when the main and base sections of the housing are in a predetermined orientation relative to each other. The retainer elements (20) press the main and base sections (14 and 16) of the housing (12) together and securely interconnect the main and base sections of the housing. A diaphragm (82) is formed in an end portion of the main section (14) of the housing (12) opposite from the retainer elements (20). A ridge (88) projects axially outward from the diaphragm (82) to protect the diaphragm and decouple the diaphragm from a side wall (74) of the housing (12). Acoustically absorptive material (114 and 116) is disposed in the housing.

Abstract: An interpenetration apparatus for the measurement of a magnitude of a blasting vibration comprises a housing including a fixture and a mover divided into two, symmetrically, in a longitudinal direction, in which the fixture includes a space for receiving a cable and the mover includes at least two grooves perforated to receive sensors, respectively; a head portion for fixing the front end of coupled fixture and mover to prevent the escape of the mover from the fixture; a handle including a fixing rod threadedly coupled to the rear portion of the fixture; a connecting rod connected to the fixing rod and extended in a predetermined length therefrom to insert the interpenetration apparatus into a working hole perforated adjacent to an approach to a tunnel; and a traction tool connected to the rear end of the mover to operate the mover, thereby enabling the housing to be at the nearest position from the blasting place, and sensitively detecting the wave motion of the blasting vibration as well as three dimensiona

Abstract: A waterproof microphone and speaker (10) having a waterproof handle (12). A waterproof microphone (14) is securely attached to a top end of the handle (12). At least one microchip (16) is contained within the handle (12). The microphone (14) is electrically connected to the at least one microchip (16). A battery (18) is contained within the handle (12). The battery (18) is electrically connected to the at least one microchip (16). A waterproof ON/OFF control (20) is contained within the handle (12). The ON/OFF control (20) is electrically connected to the at least one microchip (16). A waterproof volume control (22) is contained within the handle (12). The volume control (22) is electrically connected to the at least one microchip (16). A waterproof speaker (28) is contained within the handle (12). The speaker (28) is electrically connected to the at least one microchip (16).

Abstract: An apparatus and method for selectively locking the orientation of seismic data sensor capable of detecting data regarding a seismic event. A gimbal orients the sensor into a selected vertical orientation, and a switch operates a clutch to lock the sensor from further movement. A controller can identify a time interval correlating with a seismic event, and the controller operates the switch to lock the sensor before the seismic event begins. After the completion of the seismic event, the switch unlocks the sensor so that the gimbal can permit reorientation of the sensor. The locking mechanism eliminates noise associated with moving gimbal components and is suitable for land based and marine seismic operations.

Abstract: The subject invention is a rigid sensor array system for an underwater vele having an inner hull and an outer hull. A guide means is positioned between the vehicle's inner and outer hulls, and a sensor array panel is mounted slidably on the guide means. An exit slot is formed in said outer hull allowing the sensor array panel to slide out from between the hulls to a deployed position extending from the outer hull. The guide means is provided as tracks on either side of the array panel. In a further embodiment, a drive means is provided for moving the array panel from between the hulls to its deployed position.

Abstract: A method for monitoring production mineral reservoirs, the method comprising: permanently installing a geophone in a borehole; generating a first set of seismic waves; receiving a first set of seismic data with the geophone; recording the first set of data of said receiving a first set of seismic data; generating a second set of seismic waves after sufficient time has passed for conditions in the reservoir to have changed from the generating a first set of seismic waves; receiving a second set of seismic data with the geophone; and recording the second set of seismic data of said receiving a second set of seismic data. A method for installing instruments below the surface of the earth, the method comprising: drilling a borehole with a drill apparatus; inserting an instrument in the borehole; and permanently fixing the instrument in the borehole.

Abstract: A direction finding and ranging (DIFAR) sensor is provided in which a relatively light sensing element (30) that undergoes motion in response to an acoustic wave is disclosed. The motion of the sensing element relative to an inertial mass (2, 4) is measured along two mutually perpendicular directions to determine the direction of propagation of the acoustic wave. The construction of the DIFAR sensor enables the contact between the sensing element (30) and internally disposed relative motion transducers to be adjusted after assembly of the DIFAR sensor.

Abstract: A hydrophone arrangement, housed within a dome shaped concrete and steel bunker, to accurately establish a bearing of a target object while diminishing potential displacement of the hydrophone arrangement from an initial installed position. A plurality of hydrophones are centrally positioned within the bunker and equally spaced about a periphery of a steel cylindrical member so that each hydrophone receives acoustic energy in a time delay manner with respect to the other adjacent hydrophones so that a bearing determination may be made from information received by a single stand alone bunker. An acoustic horn may also be provided to focus the acoustic energy towards the hydrophones to improve the signal-to-noise ratios and provide control of the phase of the acoustic energy as the energy is received by the hydrophones.

Abstract: A method for monitoring production mineral reservoirs, the method comprising: permanently installing a geophone in a borehole; generating a first set of seismic waves; receiving a first set of seismic data with the geophone; recording the first set of data of said receiving a first set of seismic data; generating a second set of seismic waves after sufficient time has passed for conditions in the reservoir to have changed from the generating a first set of seismic waves; receiving a second set of seismic data with the geophone; and recording the second set of seismic data of said receiving a second set of seismic data. A method for installing instruments below the surface of the earth, the method comprising: drilling a borehole with a drill apparatus; inserting an instrument in the borehole; and permanently fixing the instrument in the borehole.

Abstract: An isolation housing is used to isolate a sensor, such as a hydrophone, f pressure fluctuations or other adverse conditions caused by fluid flow in a fluid environment. The isolation housing includes a cap portion that receives the sensor and fluid from the fluid environment. The isolation housing further includes a mounting portion that mounts the housing to a structure disposed in the fluid environment. When the sensor is a hydrophone, the cap portion is made from a material having an acoustic impedance that matches the surrounding fluid environment. The cap portion further includes one or more apertures allowing gas bubbles to escape from within the cap portion. The isolation housing further includes a retaining device, such as a resilient member, that retains the sensor centrally within the cap portion and isolates the sensor from structural vibrations or other adverse effects caused by the structure.

Abstract: A repairable geophone housing having a fully molded waterproof one piece upper body which is seabably and releasably connectible to a lower body. All surfaces within the upper body are bonded to prevent moisture entering and the geophone transducer may be replaced if desired.

Abstract: A sound amplification system includes an amplifier and a waterproof microphone. In an exemplary embodiment the microphone includes a transducer within a cavity covered by a resilient waterproof membrane. The system can monitor either the complete frequency range of the microphone or only one or more selected frequency ranges. The system can include one or more noise emitting lures that produce sound in a frequency range corresponding to the one or more selected frequency ranges. The invention also includes a method of waterproofing a miniature microphone.

Abstract: A hydrophone housing includes a hydrophone module, or cap, which contains a hydrophone. The hydrophone housing clamps around a marine seismic cable. The hydrophone housing farther includes a first portion and a second portion. One of the portions has a receiving recess, The hydrophone cap installs on this receiving recess. The portions each include a contact surface which contacts the cable when the portions fasten around the cable. The portions clamp around the cable via screws, The contact surface includes raised bosses which securely grip the cable by increasing contact pressure per unit area in a region of contact between the raised bosses and the cable.In another feature, the portion which contains a receiving recess further includes a wire-clearance recess and a wire passageway, between the receiving recess and the wire-clearance recess.In another feature, an outer cylindrical surface of each hydrophone cap is flush with an outer cylindrical surface of each hydrophone housing.