A marine seismic exploration method and system comprised of continuous recording, self-contained ocean bottom pods characterized by low profile casings. An external bumper is provided to promote ocean bottom coupling and prevent fishing net entrapment. Pods are tethered together with flexible, non-rigid, non-conducting cable used to control pod deployment. Pods are deployed and retrieved from a boat deck configured to have a storage system and a handling system to attach pods to cable on-the-fly. The storage system is a juke box configuration of slots wherein individual pods are randomly stored in the slots to permit data extraction, charging, testing and synchronizing without opening the pods. A pod may include an inertial navigation system to determine ocean floor location and a rubidium clock for timing. The system includes mathematical gimballing. The cable may include shear couplings designed to automatically shear apart if a certain level of cable tension is reached.

A marine seismic exploration method and system comprised of continuous recording, self-contained ocean bottom pods characterized by low profile casings. An external bumper is provided to promote ocean bottom coupling and prevent fishing net entrapment. Pods are tethered together with flexible, non-rigid, non-conducting cable used to control pod deployment. Pods are deployed and retrieved from a boat deck configured to have a storage system and a handling system to attach pods to cable on-the-fly. The storage system is a juke box configuration of slots wherein individual pods are randomly stored in the slots to permit data extraction, charging, testing and synchronizing without opening the pods. A pod may include an inertial navigation system to determine ocean floor location and a rubidium clock for timing. The system includes mathematical gimballing. The cable may include shear couplings designed to automatically shear apart if a certain level of cable tension is reached.

Seismic autonomous underwater vehicles (AUVs) for recording seismic signals on the seabed. The AUV may be negatively buoyant and comprise an external body (which may be formed of multiple housings) that substantially encloses a plurality of pressure housings. Portions of the external body housing may be acoustically transparent and house one or more acoustic devices for the AUV. The AUV may comprise a main pressure housing that holds substantially all of the electronic components of the AUV, while a second and third pressure housing may be located on either side of the main pressure housing for other electronic components (such as batteries). A plurality of external devices (such as acoustic devices or thrusters) may be coupled to the main pressure housing by external electrical conduit. The AUV may comprise fixed or retractable wings for increased gliding capabilities during subsea travel.

A marine seismic exploration method and system comprised of continuous recording, self-contained ocean bottom pods characterized by low profile casings. An external bumper is provided to promote ocean bottom coupling and prevent fishing net entrapment. Pods are tethered together with flexible, non-rigid, non-conducting cable used to control pod deployment. Pods are deployed and retrieved from a boat deck configured to have a storage system and a handling system to attach pods to cable on-the-fly. The storage system is a juke box configuration of slots wherein individual pods are randomly stored in the slots to permit data extraction, charging, testing and synchronizing without opening the pods. A pod may include an inertial navigation system to determine ocean floor location and a rubidium clock for timing. The system includes mathematical gimballing. The cable may include shear couplings designed to automatically shear apart if a certain level of cable tension is reached.

A time synchronization system includes: a position information acquisition unit configured to acquire installation position information related to an installation position of a time synchronization target whose time is synchronized; a time synchronization signal acquisition unit configured to receive a positioning signal transmitted from a positioning satellite as a time synchronization signal and acquire, from the time synchronization signal, transmission position information related a position of the positioning satellite and transmission time information at timing when the time synchronization signal is transmitted; and a signal processing unit configured to calculate synchronized time information for the time synchronization target based on the installation position information of the time synchronization target and the transmission position information and transmission time information from the time synchronization signal, and transmit the synchronized time information to the time synchronization target.

The adjustable voltage regulator under control of a microcontroller applies controlled amplitude voltage in the range of 5 to 9 VDC to the sensor transmitter to adjust the output amplitude of the transmitter. The adjustable amplitude transmitter allows an occupancy sensor to have its total output energy adjusted to reduce environmental noise-induced false triggering and to conform to the area to be covered. Lowering the total ultrasonic energy in the monitored space lowers the sensitivity of the receiver to inappropriate activations. Lowering the input power to the transmitter also lowers the total internal system noise and provides an improved signal to noise ratio in the receiver.

Systems and methods are disclosed. The method includes determining first metadata for a first seismic data file from a first database, generating a control file using the first metadata, and converting the first seismic data file in a predetermined file format to a destination file format using the control file. The first metadata comprises first values of a first plurality of seismic survey geometry parameters. The method further includes storing a first metadata file in a second database, wherein the first metadata file comprises the first metadata, and storing the first seismic data file in the destination file format in the second database. The method still further includes determining whether the first values of the first plurality of seismic survey geometry parameters duplicate second values of the first plurality of seismic survey geometry parameters.

A submersible node and a method and system for using the node to acquire data, including seismic data is disclosed. The node incorporates a buoyancy system to provide propulsion for the node between respective landed locations by varying the buoyancy between positive and negative. A first acoustic positioning system is used to facilitate positioning of a node when landing and a second acoustic positioning system is used to facilitate a node transiting between respective target landed locations.

A multimode seismic survey system is disclosed where seismic information for a given seismic survey is read out by different seismic units using different modes. Such multimode systems encompass hybrid arrays where information is read out via different output modes for a single seismic event, and other multimode arrays where seismic information is read out via different modes for different seismic events. The modes utilized in such arrays may include wireless, nodal and/or cable modes. The multimode arrays can be implemented using multimode seismic units or single mode seismic units. In any event, the multimode arrays can be utilized to achieve a combination of advantages associated with the different readout modes or to address any of various multimode mode contexts in relation to seismic surveys.

A multichannel streamer cable includes a plurality of vibration receiving units connected in series. The vibration receiving units each include a geophone that receives vibration of a sound wave under water, an amplifier that amplifies a signal output from the geophone, an AD converter that digitizes the signal amplified by the amplifier, and a processing section that performs processing for causing an internal memory to store, as measurement data, a digital signal obtained by digitizing the amplified signal by the AD converter.