Abstract: A distributed optical acoustic sensor is provided along a structure in a body of water. The distributed optical acoustic sensor is used to detect acoustic waves generated by at least one acoustic source for positioning of at least one object in relation to the structure.

Abstract: A technique facilitates collection and use of data on subterranean formations. The technique comprises creating a distributed sensor network having multiple sensors arranged in a desired pattern. The distributed sensor network is employed to collect seismic data from the multiple sensors. Additionally, the distributed network and sensors are designed to collect gravity data from the multiple sensors. The sensors may be arranged in a variety of environments, including land-based environments and seabed environments.

Abstract: A technique facilitates collection and use of data on subterranean formations. The technique comprises obtaining gravity measurements through the use of seismic streamers. At least one streamer is provided such that each streamer has multiple sensors, e.g. accelerometers. The at least one streamer is towed with a tow vessel, and gravity data are accumulated via the multiple sensors during towing.

Abstract: A sensor assembly includes a housing structure, a seismic sensor in the housing structure to measure seismic waves propagated through a subterranean structure, and a pressure sensor in the housing structure. A processor in the housing structure is configured to receive a first signal based on an output of the seismic sensor, and a second signal based on an output of the pressure sensor. First and second digital filters are applied to the first and second signals. Application of the first and second digital filters to the first and second signals causes production of a substantially zero output in response to input that includes just noise data detected at the seismic sensor and the pressure sensor.

Abstract: A sensor assembly having improved characteristics for use in surveying a subterranean structure includes a divergence sensor for positioning at or below a ground surface, where the divergence sensor includes a container containing a material and a pressure sensor immersed in the material. In addition, the sensor assembly includes a single-component seismic sensor that is external to the container of the divergence sensor.

Abstract: To perform noise attenuation for seismic surveying, a sensor assembly is deployed on a ground surface, where the sensor assembly has a seismic sensor to measure seismic waves propagated through a subterranean structure, and a divergence sensor comprising a pressure sensor to measure noise. First data is received from the seismic sensor, and second data is received from the divergence sensor. The first data and the second data are combined to attenuate noise in the first data.

Abstract: Passive seismic data is collected from measurements of seismic sensors in respective sensor assemblies, where the passive seismic data is based on measurements collected during periods when no active seismic source was activated. Attenuation of surface noise in the passive seismic data is performed using data from divergence sensors in at least some of the sensor assemblies. The passive seismic data with surface noise attenuated is output to allow for performing an operation related to a subterranean structure using the passive seismic data with the surface noise attenuated.

Abstract: A technique includes obtaining first data indicative of seismic measurements acquired by seismic sensors of a first set of towed streamers and obtaining second data indicative of seismic measurements acquired by seismic sensors of a second set of towed streamers. The second set of towed streamers is towed at a deeper depth than the first set of towed streamers. The technique includes interpolating seismic measurements based on the first and second data. The interpolation includes assigning more weight to the second data than to the first data for lower frequencies of the interpolated seismic measurements.

Abstract: An apparatus includes an array of seismic sensor units that are adapted to acquire measurements in connection with a land surface-based seismic survey. Each seismic sensor unit includes a particle motion sensor and a rotation sensor.

Abstract: A technique includes obtaining first data indicative of seismic measurements acquired by seismic sensors of a first set of towed streamers and obtaining second data indicative of seismic measurements acquired by seismic sensors of a second set of towed streamers. The second set of towed streamers is towed at a deeper depth than the first set of towed streamers. The technique includes interpolating seismic measurements based on the first and second data. The interpolation includes assigning more weight to the second data than to the first data for lower frequencies of the interpolated seismic measurements.

Abstract: In a first aspect, a method for use in a time lapse, marine seismic survey includes accessing a set of baseline seismic data; accessing a set of acquired, time lapse seismic data; and interpolating a set of time lapse seismic data from the baseline seismic data and the acquired time lapse seismic data, at least one of the baseline seismic data and the acquired time lapse seismic data being multicomponent data. In other aspects, a program storage medium is encoded with instructions that, when executed by a computing device, perform the above method and a computing apparatus programmed to perform one or more of such methods.

Abstract: A method of determining at least one parameter of a waveguide (3) from wavefield data acquired from wave propagation in the waveguide including obtaining first and second dispersion curves (9a, 9b, 9c) in the frequency domain from the wavefield data. A frequency interval between the first dispersion curve and the second dispersion curve is found, and this is used in the determination of at least one parameter of the waveguide. The frequency separation ?ƒ(V) between the first and second dispersion curves may be found at a particular value of the phase velocity V, and the thickness h of the waveguide can be found using: ? ? ? f ? ( V ) = c 1 2 ? h ? 1 - c 1 2 V 2 Here, c1 is the velocity of wave propagation in the waveguide. This may be found from the asymptotic velocity values of the dispersion curves.

Abstract: A method of and apparatus for processing seismic data. A method of processing seismic data comprising the steps acquiring seismic data in at least two shots that have different source-receiver azimuths from one another, and selecting events arising from interface seismic waves in each shot. The interface wave events are processed to provide information about azimuthal dependence of the velocity of seismic energy in the near-surface of the earth's interior. The invention may be used to process events arising from Scholte waves in marine seismic data, or to processing events arising from Love waves or Rayleigh waves in land seismic data. The method may be applied to seismic data acquired specifically to provide information about the near-surface or to seismic data acquired to provide information about the underlying geological structure.

Abstract: A method of determining at least one parameter of a waveguide (3) from wavefield data acquired from wave propagation in the waveguide comprises obtaining first and second dispersion curves (9a, 9b, 9c) in the frequency domain from the wavefield data. A frequency interval between the first dispersion curve and the second dispersion curve is found, and this is used in the determination of at least one parameter of the waveguide.

Abstract: A method of analysing a seismic signal comprising two orthogonal horizontal components, the method comprising using two geophones to record data corresponding to each component, and generating a frequency dependent calibration operator to correct the data corresponding to one component using the shear wave data corresponding to the other component in order to compensate for different coupling between the geophone and each component of the signal.