A method for performing a seismic survey of an earthen subterranean formation includes deploying a node patch including a plurality of seismic receivers to an offshore seabed in a survey area, deploying a surface vessel towing an array of seismic sources to the survey area located, and activating the array of seismic sources to generate seismic waves as the array of seismic sources are transported in an inline direction through the survey area whereby an imaging activation pattern and a velocity activation pattern are formed, wherein a lateral offset between the velocity activation pattern and the node patch is greater than a lateral offset between the imaging activation pattern and the node patch.

A method includes receiving seismic data of a seismic survey; defining a two-dimensional domain in dimensions x and y; identifying a target trace (S, R) of the seismic survey where S represents a source at (x.sub.s, y.sub.s) and where R represents a receiver at (X.sub.R, y.sub.R); defining with respect to the two-dimensional domain, a source trace (S, X.sub.1) as a primary trace, a receiver trace (R, X.sub.2) as a primary trace, and a generator trace (X.sub.1, X.sub.2) as associated with an interbed multiple generator; convolving the primary traces and crosscorrelating with the generator trace for a plurality of different (X.sub.1, X.sub.2) pairs where each of the plurality of (X.sub.1, X.sub.2) pairs defines a line segment where the line segments are substantially parallel to one another; and, based at least in part on the convolving the primary traces and crosscorrelating with the generator trace, generating seismic data with attenuated multiple energy.

Techniques are disclosed relating to performing marine surveys according to dither values generated based on one or more dithering constraints. This may include for example, determining a set of nominal shot points for a marine seismic energy source and determining dither values for ones of the nominal shot points. In some embodiments, the dither values are randomly generated, subject to a duplication constraint such that at most a threshold number of dither differences between consecutive shot points that fall within discrete ranges. In some embodiments, actual shot points are determined for the planned sail line based on application of the determined dither values to the nominal shot points. In various embodiments, the disclosed techniques may facilitate a separate de-blending procedure to separate signals from the marine seismic energy source and signals from one or more other seismic energy sources to be used for the seismic survey.

A seabed object detection system is provided. The system can include a source array. The source array can include a first source and a second source. The system can include a data processing system including one or more processors. The data processing system can determine a position of the first source and can identify a first firing time of the second source. The data processing system can initiate a first source shot of the first source at a known position and the second source at a known time. The data processing system can determine a target position and estimated position for the first source. The data processing system can determine a second position of the first source based on a difference between the target position and the estimated position. The data processing system can initiate a second source shot of the first source at a known position.

A method for reducing inline directivity of an air-gun source signature by optimizing spatial distribution of air-guns is provided according to the present application, which relates to a field of design and optimization of an air-gun source. An evaluation standard in the air-gun distribution in an air-gun array direction is proposed. By a combination optimization along both the inline and depth directions, a design scheme having evidently broader effective bandwidth and effective take-off angle width than a design scheme of a conventional source is obtained, with which the directivity of the air-gun source signature can be reduced.

A method for conducting a seismic survey for collecting seismic data off shore. It comprises a first seismic survey providing a first set of data for an area using individual seismic sub-source arrays (2). It further comprises a second seismic survey of the same area for providing a second set of data. The individual seismic sub-source arrays (2) are similar to the sub-source arrays used during the former survey and are arranged in more than two shot-unit sources (3). Each shot-unit source (3) comprises a pair of neighboring individual seismic sub-source arrays (2) arranged to be fired substantially at the same time.

A sub-bottom geophysical imaging apparatus includes a carriage assembly having at least one acoustic transmitter, and at least one acoustic receiver proximate the transmitter. A position determining transponder is mounted on the carriage. A plurality of position transponders is disposed at spaced apart positions to communicate with the transponder mounted on the carriage. A pair of tracks is provided for moving the carriage to selected positions above the bottom. Electrodes are provided for a resistivity sensor and a shear acoustic transmitter and receiver disposed in at least one of the pair of tracks. A signal processing unit is configured to coherently stack and beam steer signals detected by the line array, the electrodes and the shear transmitter and receiver. The signal processing unit is configured to record signals detected by the line array of acoustic receivers, the electrodes and the shear acoustic transmitter and receiver.

The present invention relates to a seismic source array for deploying a seismic source array, comprising a housing and a plurality of seismic sources suspending from the housing, each source being configured for generating a pressure pulse signal, wherein the array further comprises a protective structure attached to the housing and defining a protective space near the housing, wherein the seismic sources in a first position relative to the housing suspend from the housing such as to be arranged in the protective space defined by the protective structure, and wherein at least one of the seismic sources suspends from the housing by means of a suspension structure configured for moving the at least one seismic source to a second position relative to the housing, the second position being located outside the protective space.

Systems and methods of near surface imaging and hazard detection with increased receiver spacing are provided. The system includes: a first string of one or more acoustic sources, a second string of one or more acoustic sources opposite the first string, a first one or more hydrophones mounted within a predetermined distance of the first string, and a second one or more hydrophones mounted within the predetermined distance of the second string. The first one or more hydrophones records an acoustic shot generated from the first string. The second one or more hydrophones records the acoustic shot and acoustic reflections corresponding to the acoustic shot. The system generates an image from the recorded acoustic shot and the acoustic reflections.

A method includes receiving seismic data of a seismic survey; defining a two-dimensional domain in dimensions x and y; identifying a target trace (S, R) of the seismic survey where S represents a source at (x.sub.s, y.sub.s) and where R represents a receiver at (X.sub.R, y.sub.R); defining with respect to the two-dimensional domain, a source trace (S, X.sub.1) as a primary trace, a receiver trace (R, X.sub.2) as a primary trace, and a generator trace (X.sub.1, X.sub.2) as associated with an interbed multiple generator; convolving the primary traces and crosscorrelating with the generator trace for a plurality of different (X.sub.1, X.sub.2) pairs where each of the plurality of (X.sub.1, X.sub.2) pairs defines a line segment where the line segments are substantially parallel to one another; and, based at least in part on the convolving the primary traces and crosscorrelating with the generator trace, generating seismic data with attenuated multiple energy.