Abstract: An electromagnetic survey sensing device includes at least two electrodes disposed at spaced apart locations. An electrical to optical converter is electrically coupled to the at least two electrodes. The converter is configured to change a property of light from a source in response to voltage imparted across the at least two electrodes. The device includes an optical fiber optically coupled to an output of the electrical to optical converter, the optical fiber in optical communication with a detector.

Abstract: An electromagnetic survey sensing device includes at least two electrodes disposed at spaced apart locations. An electrical to optical converter is electrically coupled to the at least two electrodes. The converter is configured to change a property of light from a source in response to voltage imparted across the at least two electrodes. The device includes an optical fiber optically coupled to an output of the electrical to optical converter, the optical fiber in optical communication with a detector.

Abstract: An optical sensor cable includes at least one light source fiber extending substantially the entire length of the cable. A plurality of optical sensors are functionally coupled at an input thereof to the at least one light source fiber. At least one signal return fiber extends substantially along the entire length of the cable and is functionally coupled to an output of each of the optical sensors. The at least one source light fiber and the at least one signal return fiber are configured to be coupled at either end thereof to a respective one of a light source and a photodetection device.

Abstract: An optical sensor cable includes at least one light source fiber extending substantially the entire length of the cable. A plurality of optical sensors are functionally coupled at an input thereof to the at least one light source fiber. At least one signal return fiber extends substantially along the entire length of the cable and is functionally coupled to an output of each of the optical sensors. The at least one source light fiber and the at least one signal return fiber are configured to be coupled at either end thereof to a respective one of a light source and a photodetection device.

Abstract: An electromagnetic survey sensing device includes at least two electrodes disposed at spaced apart locations. An electrical to optical converter is electrically coupled to the at least two electrodes. The converter is configured to change a property of light from a source in response to voltage imparted across the at least two electrodes. The device includes an optical fiber optically coupled to an output of the electrical to optical converter, the optical fiber in optical communication with a detector.

Abstract: A lateral force and depth control device for a seismic streamer includes an inner housing including a coupling at each longitudinal end thereof. The couplings are configured to mate with a corresponding coupling at a longitudinal end of a streamer segment. The device includes an outer housing rotatably supported on the inner housing. A signal communication device is configured to transfer at least one of electrical power and signals between the inner housing and the outer housing while enabling relative rotation therebetween. A plurality of control surfaces are rotatably coupled to the outer housing and arranged about the circumference of the outer housing. The control surfaces are coupled to the outer housing by releasable couplings. A first controllable actuator and a second controllable actuator are disposed in the outer housing and functionally coupled to at least a first and a second one of the control surfaces, respectively.

Abstract: An optical accelerometer includes means for changing the length of at least one optical fiber in response to acceleration functionally coupled to the at least one optical fiber. The fiber and the means for changing length are enclosed in a pressure compensated housing. The housing is filled with a substantially incompressible fluid or gel.

Abstract: An optical accelerometer includes a beam and at least one optical fiber affixed to one side of the beam such that deflection of the beam changes a length of the optical fiber. A device for sensing the change in length of the optical fiber is functionally coupled to the at least one fiber. A seismic sensor system includes at least two accelerometers, oriented such that their sensitive axes are at least partially aligned along mutually orthogonal directions. Each accelerometer includes a beam, and at least one optical fiber affixed to one side of the beam such that deflection of the beam changes a length of the at least one optical fiber. A device for sensing the change in length of the optical fiber is functionally coupled to the at least one fiber of each accelerometer.

Abstract: An optical fiber sensor array is disclosed which includes a first sensor fiber and a first reference fiber coupled at one end thereof to one side of a first optical coupling. A first wavelength selective reflector is coupled to the other end of each of the first sensor fiber and the first reference fiber. A second sensor fiber is coupled at one end to one side of a second optical coupling. The other side of the second optical coupling is coupled to an opposite side of one of the first wavelength selective reflectors coupled on one side to the first sensor fiber and the first reference fiber. The array also includes a second wavelength selective reflector coupled to the other end of each of the second sensor fiber and the second reference fiber. The second wavelength selective reflectors are operative at a wavelength different from an operative wavelength of the first wavelength selective reflectors.

Abstract: An apparatus for making a marine seismic streamer includes a conveyor for transporting assembled mechanical harness from a storage device therefor to a storage device for storing completed marine streamer. The apparatus includes a first extruder for filling the harness with a void fill material and a second extruder for depositing jacketing material onto the filled harness both extruders being intermediate the two storage devices. A means for changing state of the void filling material is disposed proximate an outlet of the first extruder. In one embodiment, the means for changing state includes a radiation source.

Abstract: A method and system for interrogating a seismic sensor in a seismic cable having modular sensing stations spaced along the seismic cable and a connection module head end of the sensor sections, that includes dropping, at the connection modules, a wavelength of light from an input bus telemetry fiber that includes multiple wavelengths of light, distributing the dropped wavelength of light to the seismic sensor, returning the dropped wavelength from the seismic sensor to a return telemetry fiber, remultiplexing the dropped wavelength of light onto the return bus telemetry, and amplifying, in the seismic cable, the returned dropped wavelength.

Abstract: A method for attaching seismic sensors in a seismic cable that includes a strength member inside a cable jacket with a fiber tube wound around the strength member and a sensor station base attached around the cable wherein the jacket is removed, at least one fiber tube is extracted and a seismic sensor is attached to the fiber tube.

Abstract: An apparatus, system, and method are provided for interrogating of optical seismic sensors in a seismic cable. According to various example embodiments of the invention, distribution, return, and amplification of optical signals is performed near sensors for improvement of modularity of construction, signal-to-nose ratios, and simplicity of operations.

Abstract: A connector is disclosed for joining two cable ends. The connector includes a load transfer plug adapted to couple to a strength member in each end of the cable. A connector insert assembly is coupled to an inner portion of each load transfer plug. Conductor terminals are disposed in corresponding openings of the insert. The terminals protrude from the insert. An alignment sleeve holder is coupled to one of the insert assemblies. The alignment sleeve holder includes alignment sleeves for receiving the protruding terminals. A housing element is sealingly coupled to an exterior of each of the plugs. The housing elements are adapted to coupled to each other and to urge the connector insert assemblies into contact with each other, and to transfer axial load between the plug coupled to each end of the cable. The housing elements have rotational and axial alignment features on corresponding surfaces. The housing elements are adapted to be removed from the plugs without uncoupling the cable from the plug.

Abstract: An apparatus, system, and method are provided for interrogating of optical seismic sensors in a seismic cable. According to various example embodiments of the invention, distribution, return, and amplification of optical signals is performed near sensors for improvement of modularity of construction, signal-to-nose ratios, and simplicity of operations.

Abstract: The claimed invention is an apparatus, method and system for optimizing bandwidth utilization of demodulators in a system for seismic signal processing, wherein the apparatus comprises demodulators having bandwidths, wherein one demodulator's bandwidth is greater than another demodulator's bandwidth. The apparatus further comprises an optical switch coupled to a fringe rate detector, wherein optical fibers bear seismic signals having fringe rates detected by the fringe rate detector. The optical signals are switched among the demodulators in dependence upon the fringe rates. Further, the claimed invention is an apparatus, method and system for active gain ranging of demodulated signal outputs.

Abstract: There is provided a fiber-optic hydrophone having a compliant sensing mandrel coaxial with and adjacent to a rigid reference mandrel. A first optical fiber is wound around the compliant sensing mandrel and a second optical fiber is wound around the reference mandrel. The first and second optical fibers comprise different arms of an interferometer. Flexible sealing members, such as O-rings, seal the compliant sensing mandrel to the hydrophone. One O-ring is disposed near each end of the sensing mandrel. A cylindrical support member is disposed inside the sensing mandrel. At least a portion of the support member is spaced from the sensing mandrel so as to provide a sealed cavity between the sensing mandrel and the support member. The sealed cavity is filled with air or similar compliant substance.

Abstract: The claimed invention is an apparatus, method and system for optimizing bandwidth utilization of demodulators in a system for seismic signal processing, wherein the apparatus comprises demodulators having bandwidths, wherein one demodulator's bandwidth is greater than another demodulator's bandwidth. The apparatus further comprises an optical switch coupled to a fringe rate detector, wherein optical fibers bear seismic signals having fringe rates detected by the fringe rate detector. The optical signals are switched among the demodulators in dependence upon the fringe rates. Further, the claimed invention is an apparatus, method and system for active gain ranging of demodulated signal outputs.

Abstract: Several embodiments of an apparatus for remote amplification of seismic sensor fiber optical signals from seismic sensor arrays are disclosed. The seismic sensor fiber optical signals are transmitted using FDM/WDM and TDM/WDM techniques. Embodiments of the invention allow for modular structure of the seismic sensor arrays, wherein the excess of the pumped optical energy is used to amplify another module of the sensor arrays. The sensor arrays can be arranged in serial and/or parallel configuration. An embodiment of the invention allows for repeated amplification of the seismic sensor fiber optical signals using pumped optical energy from a single source. In another aspect of the invention, systems corresponding to the apparatus and methods of using the systems are disclosed.

Abstract: A fiber optic signal separator for separating and amplifying signal components from multiplexed signal using a three port optical circulator, a grating and integral signal amplification components is described. Another example embodiment of the signal separator uses a four port optical circulator, one or more grating and integral optical amplification components. A signal multiplexer using a three port optical circulator, a grating and integral signal amplification components is described. Another example embodiment of the signal multiplexer uses a four port optical circulator, one or more gratings and optical amplification components for integral amplification of the signal.