Abstract: A method is disclosed comprising: transmitting a pair of tracking signals, the pair of tracking signals including a first tracking signal and a second tracking signal; receiving a data set that is collected by using a sensor in a sensor array, the data set including: (i) a received first tracking signal that is generated by the sensor in response to receiving the first tracking signal, (ii) a received second tracking signal that is generated by the sensor in response to receiving the second tracking signal, and (iii) a received target signal; detecting a relative delay at which the first tracking signal and the second tracking signal are received by the sensor; removing the received first tracking signal and the received second tracking signal from the data set to produce a filtered data set; and providing the filtered data set and an indication of the relative delay to a beamformer.

Abstract: The main components of an exemplary inventive simulation are a towing platform (such as a ship), a towed body, an underwater vehicle (such as a UUV), and a tow cable connecting the towing platform and the towed body. An objective of the dynamic arrangement of the components is to perform a “line capture” of the moving vehicle by the cable. Respective motions and positions of the towing platform and the towed body affect the cable. Waves and currents in the water, as well as changes in catenary and tension of the cable, affect the tow body. Advantageously, the invention more accurately accounts not only for continuities, but also for discontinuities, characterizing the dynamic interrelationships between and among the components. Among the invention's features is its ability to “trigger” consideration of certain dynamic manifestations relating to the vehicle, depending on whether or not the vehicle is in a captured state.

Abstract: Systems and methods for reducing survey time while enhancing acquired seismic data quality are provided. Data corresponding to plural source lines are acquired simultaneously, using sources at cross-line distance at least equal to their illumination width, with at least one source being towed above a streamer spread.

Abstract: Numerous techniques and apparatus are disclosed relating to the performance of 4D marine geophysical surveys over at least first and second areas covered, respectively, by first and second preexisting baseline surveys. Performing the monitor surveys may include deploying a monitor survey streamer layout that can be used to repeat streamer positions of both the first and the second preexisting baseline surveys, and using the monitor survey streamer layout to perform the monitor survey over the first and second areas in a manner that repeats all streamer positions of the first preexisting baseline survey when over the first area, and that repeats all streamer positions of the second preexisting baseline survey when over the second area. Streamer layouts corresponding to the first and second preexisting baseline surveys may differ in at least one of the following characteristics: streamer separation or total number of streamers.

Abstract: A non-blended dataset related to a same surveyed area as a blended dataset is used to deblend the blended dataset. The non-blended dataset may be used to calculate a model dataset emulating the blended dataset, or may be transformed in a model domain and used to derive sparseness weights, model domain masking, scaling or shaping functions used to deblend the blended dataset.

Abstract: A frictionless access control system and method providing ultrasonic user location are disclosed. The access control system authorizes users within proximity of an access point such as a door, based upon user information (e.g. credentials) sent in RF wireless messages from user devices carried by the users. When the users are authorized, the system instructs the user devices to transmit coded acoustic signals. An positioning unit at the access point includes an ultrasonic microphone array, which is located above the access point and detects the acoustic signals. The positioning unit determines an angle of arrival (AoA) of the acoustic signals at microphones of the array, and determines positions of the users relative to the access point from the AoA. In one implementation, pre-authorized users are granted access when the determined positions of the users are within an inner zone of the access point.

Abstract: Included are methods and apparatus for marine geophysical surveying. One embodiment of the presently-disclosed solution relates to a method for instantaneous roll compensation of vectorised motion data originating from a fixed-mount geophysical sensor during a marine seismic survey. A streamer is towed behind a survey vessel in a body of water. The streamer includes a plurality of geophysical sensors and a plurality of orientation sensor packages, and each orientation sensor package comprises a magnetometer. Vectorised geophysical data is acquired using the plurality of geophysical sensors, while orientation data is acquired by the plurality of orientation sensor packages. The orientation data is used to determine an instantaneous roll angle of the streamer at different positions on the streamer. The vectorised geophysical data is adjusted to compensate for the instantaneous roll angle of the streamer at different positions on the streamer. Other embodiments and features are also disclosed.

Abstract: Exploration of resources of the bottom of water such as a seafloor based on a self-potential is accurately performed. A computer of a resource estimation system includes an estimation information acquisition unit that acquires potential information indicating potentials of a plurality of potential electrodes having a predetermined positional relationship measured at a plurality of positions in water, a noise removal unit that removes noise contained in the measured potentials by performing principal component analysis or independent component analysis using the potentials, and a resource estimation unit that estimates the presence of the resources in the bottom of water based on the potential from which the noise has been removed.

Abstract: A method for acquisition of seismic data in a marine environment.

Abstract: A ranging system comprises a plurality of streamers, each with a plurality of receivers. A plurality of transmitters is also disposed along one or more of the streamers, each configured to generate acoustic or ranging signals over one or more channels. A processor is configured to define a subset of the transmitters within a predefined limited range or listening distance of each receiver. In the subset, the transmitters are configured to generate the acoustic signals over different channels.

Abstract: A method and apparatus are provided for steering a first acoustic linear antenna belonging to a plurality of acoustic linear antennas towed by a vessel. A plurality of navigation control devices are arranged along the plurality of linear antennas in order to act at least laterally on the position of the linear antennas. At least one of the navigation control devices arranged along the first acoustic linear antenna performs steps of: obtaining a local measurement of a feather angle or of a parameter linked to the feather angle, the local measurement being associated with the at least one of the navigation control devices arranged along the first acoustic linear antenna; computing a lateral force, as a function of the obtained local measurement; and applying the computed lateral force.

Abstract: In the field of marine geophysical surveying, systems and methods for controlling the spatial distribution or orientation of a geophysical sensor streamer or an array of geophysical sensor streamers towed behind a survey vessel are provided. Various techniques for changing the spatial distribution or orientation of such geophysical sensor streamers in response to changing conditions are provided. For example, crosscurrent conditions may be determined based on configuration data received from positioning devices along the length of a streamer, and a new desired orientation for the streamer may be determined based on the crosscurrent conditions. The new desired orientation may include a new desired feather angle for the streamer.

Abstract: Methods and systems for efficiently acquiring towed streamer marine seismic data are described. One method and system comprises positioning a plurality of source-only tow vessels and one or more source-streamer tow vessels to acquire a wide- and/or full-azimuth seismic survey without need for the spread to repeat a path once traversed. Another method and system allows surveying a sub-sea geologic feature using a marine seismic spread, the spread smartly negotiating at least one turn during the surveying, and shooting and recording during the turn. This abstract is provided to comply with the rules requiring an abstract, allowing a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: Method for obtaining zero offset or near zero offset data in a marine seismic streamer survey. An acoustic transmitter (41) is attached to one of the buoys (14 or 16) that provide flotation to each streamer (12) and tow umbilical (13). The acoustic transmitters, or single transmitter in the case of a 2-D survey, may be fired (71-73) before each shot from the survey air guns. The response to the acoustic transmitters recorded by the near sensors in each streamer, or by a water break sensor if provided, will be a near-zero to zero-offset record of the shallow subsurface below the water bottom.

Abstract: A marine survey acquisition system. The system may include a vessel for towing a marine survey spread. The marine survey spread may include streamers, marine vibrators and a cable. The cable may be coupled to a respective streamer from among the streamers and one of the marine vibrators. The cable may power the respective streamer and the one of the marine vibrators. The one of the marine vibrators may emit energy at a high frequency range.

Abstract: A method is provided for managing a master vessel change in a multi-vessel seismic system. The system includes a master vessel M and at least one slave vessel. The method includes, during at least a part of a multi-vessel operation: selecting a new master vessel M? among the at least one slave vessel, triggered by at least one predetermined event; and transmitting, to the at least one slave vessel, at least one piece of information related to a master vessel change from the master vessel M, called old master vessel, to the new master vessel M?.

Abstract: A skeg mounts from the stern of a towing vessel and extends below the waterline. A channel in the skeg protects cables for steamers and a source (e.g., air gun array) of a seismic system deployed from the vessel. Tow points on the skeg lie below the water's surface and connect to towlines to support the steamers and the source. A floatation device supports the source and tows below the water's surface to avoid ice floes or other issues encountered at the water's surface. Seismic streamers have head floats supporting the streamers. Each of the floats has adjustable buoyancy preconfigured to counterbalance the weight in water of the towed component that the float supports. Acoustic signals from a transceiver at the vessel find locations of the towed components. A towed fish at a lower level than the towed components also uses acoustic signals with a transceiver to further refine the locations of the towed components.

Abstract: A technique includes receiving data acquired by a seismic sensor on a spread of at least one streamer. The data are indicative of a seismic source signature that is produced by a source seismic to penetrate into the Earth to acquire geophysical information in connection with a seismic survey. The technique includes processing the data to determine a position on the streamer relative to a reference position not disposed on the streamer.

Abstract: The Monte-Carlo method of generating Popcorn shooting patterns starts with the number and sizes of the guns available and the length in time of the desired Popcorn pattern. The firing times and order of the guns will be randomly perturbed and a large number of Popcorn patterns built. Candidate Popcorn patterns will then be tested against a set of criteria to identify acceptable or the best patterns. These criteria may include limits on maximum peak strength, distinctiveness compared to the other patterns, and the size of the notches and peaks in the spectra.

Abstract: A method for towing marine geophysical sensor streamers in a body of water includes moving a towing vessel at a selected speed along the surface of the body of water. At least one geophysical sensor streamer is towed by the vessel at a selected depth in the water. A velocity of the streamer in the water is measured at at least one position along the streamer. The selected speed of the towing vessel is adjusted if the measured velocity is outside of a selected range.

Abstract: A data collection system 100 for estimating a corrected sound speed between a first point and a second point comprises a subsea acoustic transponder beacon (106) disposed at a fixed position relative to a seabed (108), and an acoustic transceiver (214) immersed below a sea surface (104) and above the acoustic beacon (106). A processing resource (200) is also operably coupled to the acoustic transponder (214), the acoustic transceiver (214) being arranged to traverse a path above the acoustic beacon (106) and communicate with the acoustic beacon (106). The processing resource (200) is also arranged to collect time-of-flight data associated with the communication between the acoustic transceiver (214) and the acoustic beacon (106).

Abstract: A method for seismic prospecting in an aquatic medium using a device having at least one seismic cable provided with sensors and at least one moving seismic source. The method includes the following steps: 1) moving the cable in the water using two drones each placed at one end of the cable and which maintain tension in the cable, the movement of the cable minimizing the deviation of the cable with respect to a desired route in the terrestrial reference frame where the movement of the cable is also being restricted by a maximum track curvature value in the water, and, at the same time; and 2) moving the seismic source in a reference frame connected to the cable, emitting waves via the seismic source, and sensing reflections of the waves by the cable.

Abstract: Various methods preserve or restore the low roughness throughout an outer shell of a device (e.g., a streamer) used underwater for seismic surveys, by applying various substances that fill micro-cracks, are easy to polish or are self-healing. Apparatuses used to implement these methods may be used shortly before the devices are deployed in water, for example, having the device passing through such an apparatus as it is moved to be deployed in water.

Abstract: A method and apparatus are provided for estimating an inter-node distance between a sender node and a receiver node belonging to a network comprising a plurality of nodes arranged along towed acoustic linear antennas. An acoustic signal is transmitted from the sender node to the receiver node through an underwater acoustic channel. The method includes estimating the inter-node distance as a function of an estimate of a sound speed profile of the underwater acoustic channel, the sound speed profile depending on depth.

Abstract: Disclosed are apparatus and methods acoustic node positioning during a marine survey. In one embodiment, positions of a plurality of nodes are calibrated using acoustic transceivers. In addition, changes in the positions of the nodes are tracked using accelerometers. In another embodiment, a traveling wave is detected, and an effect of the traveling wave is projected on steering devices in a projected path of the traveling wave. Time-dependent control signals are computed and applied to the steering devices to maintain a local streamer geometry. Other embodiments, aspects, and features are also disclosed.

Abstract: A method for identifying clock timing discrepancies in at least one clock of interest that is associated with a marine seismic receiver, comprises collecting from at least one marine receiver other than the receiver of interest a first data set corresponding to a selected time period, said first data set being selected to include ocean wave signals; collecting from the receiver of interest a second data set corresponding to the selected time period, said second data set being selected to include ocean wave signals; applying a mathematical prediction technique to the ocean wave signals in the first data set so as to generate a predicted response for a receiver co-located with the receiver of interest; comparing the predicted response to the second data set so as to generate a correlation data set; and using the correlation data set to determine a corrected parameter for the receiver of interest.

Abstract: A method is proposed for acquiring seismic data relative to an area of the subsoil, wherein at least one seismic source is moved and seismic waves are emitted in successive shooting positions of the source so as to illuminate said area of the subsoil, and the signals resulting from this emissions are picked up using a set of cables having a substantially zero buoyancy and provided with receivers. The cables have a substantially zero speed or a speed substantially slower than the source in the terrestrial reference frame. And said successive shot positions are determined as a function of the position of the receivers relative to the terrestrial reference frame to optimize at least one quality criterion relating to the set of seismic signals acquired by the receivers in respect of said area. Such a method enables improved seismic data acquisition.

Abstract: A microseismic method of determining the position of a downhole receiver (4) making use of received signals from events (21, 22) at least two known locations using the equivalent of a Thales circle construction from two or more pairs of events.

Abstract: Method and system for determining positions of underwater sensors. The method includes sending a Doppler variant signal from a moving source; recording the signal with the at least one seismic sensor; evaluating a frequency drift of the recorded signal; and determining a position of the at least one seismic sensor based on the evaluated frequency drift and a source movement relative to the at least one sensor.

Abstract: A sensor streamer drag body system. At least some of the example embodiments include a system having a sensor streamer towable behind a vessel in a body of water, the sensor streamer defining a defining a distal end and a proximal end, the proximal end nearest the vessel. The system further includes a drag body coupled to the distal end of the sensor streamer, wherein the drag body remains submerged while the sensor streamer is deployed. The drag body includes an inertial navigation system. The inertial navigation system is configured to determine a position of the drag body, the drag body lacking an internal GPS.

Abstract: A seismic survey system for recording seismic data underwater. The system includes first plural buoys configured to descend to a first predetermined depth (H1) in water, at least one buoy having a seismic receiver for recording the seismic data; a first vessel configured to launch the first plural buoys; and a first acoustic system attached to the first vessel and configured to detect a position of the at least one buoy while underwater. The at least one buoy is instructed to maintain the first predetermined depth (H1) underwater while recording the seismic data.

Abstract: A method for simulating the positioning of at least one acoustic linear antenna towed in a study zone is provided. The method includes at least one simulation step of at least one future position of at least one point of the acoustic linear antenna(e), at least one step for predicting the temporal and spatial variations of at least one marine current likely to interact with the acoustic linear antenna(e) and at least one step for determining the form of the acoustic linear antenna(e) by the resolution of a hydrodynamic model. The prediction step(s) include an upstream phase for determining a current at at least two determined points of the zone; a simulation phase of at least one future position of the determined points; a temporal projection phase of the current determined during the upstream phase at each future position; and a spatial projection phase of the currents at at least two distinct points of the acoustic linear antenna(e) occupying future position(s) of the simulation step.

Abstract: A device for collecting samples of the sea floor, including a collection apparatus, a diving apparatus and a control apparatus.

Abstract: In a first embodiment the invention comprises a method for gathering geophysical data, including towing geophysical data gathering equipment behind a survey vessel in a body of water, said equipment including an array of sensor streamers extending behind said vessel, and determining a geodetic location of a streamer steering reference point at a forward end of the sensor streamers and a reference direction. At least one sensor streamer included in said array of sensor streamers is laterally deflected in response to the determined geodetic location of said streamer steering reference point and the determined reference direction.

Abstract: A method of assisting the deployment/retrieval of linear acoustic antennas towed by a vessel, said linear antennas each having geophysical data sensors, means for measuring the distance of at least one adjacent linear antenna, during the course of which at least one of said linear acoustic antennas has at least longitudinal mobility in relation to said vessel, including: at least one phase for configuring cells (Cn) each defined by a central position corresponding to a distance-measuring means (T), and by at least one peripheral position corresponding to another distance-measuring means (T) in proximity to said distance-measuring means (T) for said central position, reference distances between said central positions and said peripheral positions being predetermined; and at least one phase for controlling said central and peripheral positions with respect to said reference distances, by establishing communication between at least some of said distance-measuring means (T).

Abstract: In a first embodiment the invention comprises a method for gathering geophysical data, including towing geophysical data gathering equipment behind a survey vessel in a body of water, said equipment including an array of sensor streamers extending behind said vessel, and determining a geodetic location of a streamer steering reference point at a forward end of the sensor streamers and a reference direction. At least one sensor streamer included in said array of sensor streamers is laterally deflected in response to the determined geodetic location of said streamer steering reference point and the determined reference direction.

Abstract: Various technologies described herein are directed to a method that includes deploying a plurality of wave gliders in a seismic survey area, where the plurality of wave gliders has one or more seismic sensors coupled thereto for acquiring seismic data. The method may also include deploying at least one source vessel in the seismic survey area, where the at least one source vessel has one or more sources coupled thereto and a central communication unit disposed thereon. The method may then include positioning the plurality of wave gliders according to an initial navigation plan. The method may further include monitoring a relative position of a respective wave glider in the plurality of wave gliders with respect to other wave gliders in the plurality of wave gliders and with respect to the at least one source vessel.

Abstract: Method and streamer/source head-float system for connecting to a head portion of a streamer or to a lead-in or providing information about a source. The system includes a head-buoy configured to float in water and connected through a cable to the head portion of the streamer or to the lead-in; a head-float configured to float in water; a connector connecting the head-float to the head-buoy; and positioning equipment attached to the head-float and configured to determine a position of the streamer or the source.

Abstract: Methods for determining by acoustic ranging relative positions of marine seismic streamers in a network of streamers are described, as well as streamer configurations and systems which overcome weak or non-existent acoustic positioning signals. The acoustic network includes a plurality of acoustic transceiver pairs, and the methods include implementing a network solution-based reconfiguration of the acoustic transceiver pairs. When the network of streamers changes more than a critical amount, the network is reconfigured, the critical amount being when the network solution-based reconfiguration is no longer adequate to provide enough acoustic signals to give reasonable relative positions of the acoustic transceiver pairs in the network due to their spatial relation.

Abstract: A survey method includes towing one or more sources and one or more streamers behind a vessel to acquire geophysical survey data. Steering signals are determined for at least one of: the one or more sources, the one or more streamers, and the vessel. The steering signals minimize an error function having parameters that include a measure of a cross-line position error and a measure of data quality. The cross-line position error may be measured as an offset of the sources or the receivers from their desired paths, or in some embodiments as an offset between midpoints for base survey traces and subsequent survey traces. Some embodiments may employ a maximum spatial cross-correlation coefficient between a newly acquired trace and one or more base survey traces as a data quality measure, while others may employ a time shift, a phase rotation, or a normalized root mean square error. Data quality may indicate sensor noise levels.

Abstract: A method of obtaining information about the positions of sources in a marine seismic source array that has N seismic sources, including at least Nunique types of sources that are nominally non-identical to one another, where 1?Nunique?N?1. The method comprises measuring the pressure field at M independent locations of the N sources, where M>Nunique, and obtaining information about the positions of sources from the M pressure measurements and from the constraint that at least two of the sources are nominally identical to one another.

Abstract: A wave glider system includes a float having geodetic navigation equipment for determining a geodetic position and heading thereof. The glider includes an umbilical cable connecting the float to a sub. The sub has wings operable to provide forward movement to the float when lifted and lowered by wave action on the surface of a body of water. At least one geophysical sensor streamer is coupled to the sub. The at least one geophysical sensor streamer has a directional sensor proximate a connection between the sub and one end of the at least one geophysical sensor streamer to measure an orientation of the streamer with respect to a heading of the float.

Abstract: The present invention provides a method and apparatus for positioning a center of a seismic source. The method includes determining a desired center-of-source of the seismic source and selecting one of a first and a second plurality of guns to form the seismic source based upon the desired center-of-source, a center-of-source of the first plurality being different than a center-of-source of the second plurality.

Abstract: According to one or more aspects of the invention, a marine seismic survey method comprises towing at least two streamers below a sea surface forming a survey spread, each streamer comprising a survey sensor and a profiler; and at each profiler, emitting an acoustic signal; recording an echo of the emitted signal at the profiler; and determining a parameter from the recorded echo, the parameter comprising at least one selected from the group of a distance between the profiler and the sea surface, a water current vector and a sea surface slope.

Abstract: A method for selecting a signal arrival for determining an accurate position of seismic equipment includes the steps of transmitting a signal from a pinger; predicting a direct arrival and a reflected arrival of the signal at a receiver, wherein each arrival is the time between the transmission of the signal to reception of the signal; measuring arrivals of the signal at the receiver; selecting the measured signal arrival that is similar to the predicted direct arrival as a preliminary signal arrival; defining a confidence interval for the actual direct arrival of the signal based on the predicted direct arrival and the predicted reflected arrival; and finalizing the signal arrival, wherein the selected preliminary signal arrival is the finalized signal arrival if it is within the confidence interval.

Abstract: A method for determining correction during steering of a point on an object towed by a towing device, the object point, toward a target position, the object being provided with a bird, including the steps of determining a target position; determining the position of the object point, determining the speed and acceleration of the object point and directions of these and thereby determining an inline direction; determining whether the inline is directed toward the target position and if it deviates from the desired direction, determining a distance vector between the object point and the target position; calculating the object point distance, speed and acceleration components at least in the lateral direction or the vertical direction; and transferring values for the components to a control system for the corresponding bird.

Abstract: A method for determining geodetic position of at least one point on a geophysical sensor streamer towed by a vessel in a body of water includes determining geodetic positions of a plurality of locations along a first geophysical sensor streamer towed at a first depth in the body of water. A lateral offset is caused between the first geophysical sensor streamer and a second geophysical sensor streamer towed at a second depth in the body of water. A distance is measured between at least two selected points along the first geophysical sensor streamer and a selected point along the second geophysical sensor streamer. A depth is measured at at least one point along the second geophysical sensor streamer. A geodetic position is determined at a selected point along the second geophysical sensor using the depth measurement, a direction of the lateral offset and the measured distances.

Abstract: Disclosed are apparatus and methods acoustic node positioning during a marine survey. In one embodiment, positions of a plurality of nodes are calibrated using acoustic transceivers. In addition, changes in the positions of the nodes are tracked using accelerometers. In another embodiment, a traveling wave is detected, and an effect of the traveling wave is projected on steering devices in a projected path of the traveling wave. Time-dependent control signals are computed and applied to the steering devices to maintain a local streamer geometry. Other embodiments, aspects, and features are also disclosed.

Abstract: A method and system for controlling the shape and separation of an arrangement of streamers towed behind a survey vessel. Each streamer is steered laterally by lateral steering devices positioned along its length at specific nodes. Each streamer is driven by its lateral steering devices to achieve a specified separation from a neighboring streamer. One of these actual streamers, used as a reference by the other actual streamers, is steered to achieve a specified separation from an imaginary, or ghost, streamer virtually towed with the actual streamers.

Abstract: Computational systems and methods, to be carried out by the computational systems for determining streamer-depth bias during exploration-seismology experiments are disclosed. An exploration-seismology vessel tows a number of streamers that form a smoothly varying data acquisition surface located beneath a fluid surface. In one aspect of this disclosure, the method determines a set of image points that represent a profile of the fluid surface above each streamer. The image points are determined based on pressure and velocity wavefields measured at dual sensors of the streamer. The method then determines an elevation parameter of the image points that minimizes DC offset in a spectral domain of the image points. The elevation parameter corresponds to the streamer-depth bias and can be used to correct for the streamer-depth bias in subsequent calculations of a fluid-surface profile.