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.

An ocean bottom node for collecting seismic data, the ocean bottom node including a compounded housing including an electronics housing and a pinger housing, electronics located inside the electronics housing, and a battery pack configured to supply electrical power to the electronics. The pinger housing is permanently open to an ambient water while the electronics housing is sealed from the ambient water, and the pinger housing is configured to selectively and directly attach to the electronics housing.

An ocean bottom node for collecting seismic data, the ocean bottom node including a compounded housing including an electronics housing and a pinger housing, electronics located inside the electronics housing, and a battery pack configured to supply electrical power to the electronics. The pinger housing is permanently open to an ambient water while the electronics housing is sealed from the ambient water, and the pinger housing is configured to selectively and directly attach to the electronics housing.

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.

An acoustic vector sensor (“AVS”) includes one or more sensitive elements arranged in an orthogonal configuration to provide high-sensitivity directional performance. The one more sensitive elements may be seismometers arranged in a pendulum-type configuration. The AVS further includes a hydrophone.

An acoustic vector sensor (“AVS”) includes one or more sensitive elements arranged in an orthogonal configuration to provide high-sensitivity directional performance. The one more sensitive elements may be seismometers arranged in a pendulum-type configuration. The AVS further includes a hydrophone.

Methods and apparatus are described for using ambient acoustic energy as a passive source in marine seismic surveys. An example embodiment includes (a) accessing signals that were recorded by sensors in the presence of acoustic energy that was emitted by a passive source during a marine seismic survey; (b) identifying a point to represent a location from which the acoustic energy was emitted; (c) isolating, from the recorded signals, a direct wavefield arriving at the sensors from a direction of the identified point; and (d) generating an estimated passive source wavefield at the identified point by backpropagating the isolated direct wavefield to the identified point. The estimated passive source wavefield may be used, together with signals recorded by the sensors, to generate an image of a subsurface earth volume without the use of active seismic sources.

A long-term in-situ observation device for the deep sea bottom supported engineering geological environment is provided, including: a sediment acoustic probe, a sediment pore water pressure probe, a three-dimensional resistivity probe, a water observation instrument, a long-term observation power supply system, a probe hydraulic penetration system, a general control and data storage transmission system, an acoustic releaser, an underwater acoustic communication apparatus, and an instrument platform. The observations include the engineering properties, physical properties, mechanical properties, and biochemical properties of a seawater-seabed interface-sediment. The engineering properties and the physical and mechanical indexes of seafloor sediments are comprehensively determined by three-dimensional measurement of seafloor resistivity and acoustic wave measurements. The physical and biochemical properties of seawater are expected to be acquired by sensors. The observation probe penetrates into the sediments following the hydraulic method.

A long-term in-situ observation device for the deep sea bottom supported engineering geological environment is provided, including: a sediment acoustic probe, a sediment pore water pressure probe, a three-dimensional resistivity probe, a water observation instrument, a long-term observation power supply system, a probe hydraulic penetration system, a general control and data storage transmission system, an acoustic releaser, an underwater acoustic communication apparatus, and an instrument platform. The observations include the engineering properties, physical properties, mechanical properties, and biochemical properties of a seawater-seabed interface-sediment. The engineering properties and the physical and mechanical indexes of seafloor sediments are comprehensively determined by three-dimensional measurement of seafloor resistivity and acoustic wave measurements. The physical and biochemical properties of seawater are expected to be acquired by sensors. The observation probe penetrates into the sediments following the hydraulic method.

The invention relates to a method and system for path planning of a wave glider, comprising acquiring historical navigation data of the glider and an underwater vehicle via a shore-based monitoring center; fitting historical navigation data nonlinearly by a deep learning neural network to obtain a trained network; acquiring real-time navigation data of the glider at an off-line end, real-time navigation data and predetermined shipping track data of the vehicle; obtaining the set of off-line optimized path planning schemes of the glider by the above data and the trained network; and determining an optimal path planning scheme of the glider by the deep learning neural network according to real-time data and constraint data of the glider at the on-line end. The invention can reasonably plan the path of the glider and ensure continuous and reliable information interaction between the glider and the vehicle.