An underwater device intended to be deployed in the water, the device includes a set of arms articulated to a support body having a reference axis r, the arms being able to be kept in a furled configuration and able to deploy into a deployed configuration wherein the arms extend about the reference axis r, the arms deploying by distal ends of the arms moving away from the axis r, a set of at least one bending spring stressed elastically in bending when the arms are kept in a furled configuration and able to relax when the arms are released from the furled configuration, the set of at least one bending spring being configured and arranged in such a way as to exert, on at least one of the arms, when the arms are released from the furled configuration, a thrust that instigates the deploying of the arms.

A measurement device intended to be immersed in water, includes a set of arms and a reference axis, the measurement device being able to be in a deployed configuration, the measurement device comprising a set of measurement units borne by arms of the set of arms and each comprising an acoustic-waves sensor, the set of measurement units being configured and arranged in such a way as to generate a torque on the measurement device about the reference axis upon a vertical translational movement of the measurement device in the deployed configuration, the measurement device comprising compensation means configured and arranged in such a way as to generate another torque on the measurement device about the reference axis during the vertical translational movement, the other torque being directed in the opposite direction to the torque and having an intensity less than twice that of the torque.

A method, a system, and a device for full-waveform inversion deghosting for a marine variable depth streamer data acquisition are provided for solving existing problems that deghosted seismic data has low accuracy and is accompanied by artifacts due to a large error in ghost prediction. The provided method includes: acquiring seismic data, jointly solving Lippmann-Schwinger equations to obtain normal derivatives of an incident wave field and a wave field of a receiver surface, performing a wave field extrapolation by a Kirchhoff equation that includes only an integral on the receiver surface to obtain a wave field of a sea surface recorded by a horizontal streamer, calculating a ghost operator, and subjecting the ghosted wave field of the sea surface recorded by the horizontal streamer to full-waveform inversion deghosting to obtain deghosted seismic data. The provided method improves the accuracy and signal-to-noise ratio (SNR) of deghosted seismic data.

A seabed object detection system is provided. The system can include a receiver array including streamers. The system can include a plurality of receivers coupled with the streamers. The system can include a receiver array cross-cable to couple with the first streamer and to couple with the second streamer. The receiver array cross-cable can be disposed at a first depth of a body of water. The system can include a first diverter and a second diverter coupled with the receiver array cross-cable. The system can include a source array including a first source and a second source. The source array can be coplanar to the receiver array. The system can include a source array cross-cable to couple with the first source and to couple with the second source, the source array cross-cable disposed at a second depth of the body of water.

A method for verticalizing recorded seismic data, the method including recording first data with a particle motion sensor, wherein the particle motion sensor is located on a streamer, and the particle motion sensor is configured to be insensitive to a direct current, recording second data with a gravity motion sensor, wherein the gravity motion sensor is also located on the stream, and the gravity motion sensor is configured to be sensitive to the direct current and temporally synchronous to the particle motion sensor, selecting a cost function that associates corresponding values of the first data and the second data, determining a misalignment angle from maximizing the cost function, wherein the misalignment angle describes a misalignment between corresponding axes of the particle motion sensor and the gravity motion sensor, and correcting seismic data recorded by the particle motion sensor based on the misalignment angle so that the corrected seismic data is verticalized with regard to gravity.

Embodiments relate generally to marine geophysical surveying. More particularly, embodiments relate to a wax application system for application of a wax coating to a surface of a streamer. An embodiment may comprise a marine geophysical survey system. The marine geophysical survey system may comprise a streamer and a wax application system operable to receive the streamer on deployment and apply a wax coating to the streamer as the streamer is being deployed from a survey vessel into a body of water.

A deployment module according to the present application enables both compact stowage of a sensor array and expansion of the sensor array into a three-dimensional volumetric array shape that enables improved directionality of the sensors during operation. The deployment module includes a support shell that is configured to retain a cable of the sensor array separately from sensors of the sensor array and an expandable deployment body formed of a superelastic shape memory alloy that uses superelasticity and stored energy for deployment of the sensor array. During deployment, the deployment body is removed from the support shell and the sensors are subsequently pulled out of the support shell. The deployment body then expands and holds the cable to retain the three-dimensional volumetric shape of the deployed array.

A method may be provided to operate a wireless terminal in communication with a network node. The method may include receiving a Physical Downlink Control Channel, PDCCH, order from the network node. The PDCCH order may include an identification for a Random Access CHannel RACH occasion to be used for a RACH message 1 preamble transmission. Moreover, the identification may include a first index that indicates a set of RACH occasions and a second index that indicates the RACH occasion associated with the set. The method may also include transmitting a Message 1 preamble to the network node using the RACH occasion responsive to the PDCCH order.

This disclosure presents processes and systems for generating an image of a subterranean formation from seismic data recorded in a seismic survey of the subterranean formation. The seismic data is contaminated with low frequency noise in a low frequency band. Processes and systems reconstruct seismic data in the low frequency band of the seismic data to obtain low frequency reconstructed seismic data that is free of the low frequency noise. The low frequency reconstructed seismic data is used to construct a velocity model of the subterranean formation. The velocity model and the low frequency reconstructed seismic data are used to generate an image of the subterranean formation that reveals structures of the subterranean formation without contamination from the low frequency noise.

The invention concerns a submarine exploration system (1) comprising: a master submarine drone (2) designed to move autonomously according to a predetermined flight plan (E) and comprising a communication module (C) for transmitting communication signals; a plurality of follower submarine drones (31, 32, 33, 34, 35, 36), each comprising at least one magnetic field detection system (D), each follower drone further comprising a communication module (C) for receiving communication signals from the master drone; the master drone being designed to transmit navigation instructions (I) to the follower drones and each follower drone being designed to move autonomously depending on the movement instruction such that its movement is slaved to the movement of the master drone.