A seismic measurement system and a method of obtaining seismic measurements are described. The seismic measurement system includes a cable and a plurality of sensors disposed at a first interval along the cable. The plurality of sensors receives reflections resulting from a seismic source and each of the plurality of sensors receives the reflection corresponding with a particular subsurface location. The system also includes a controller to turn on a first set of the plurality of sensors and turn off a second set of the plurality of sensors based on an area of interest.

The present disclosure belongs to the technical field of an ultrasonic sound field measuring system, and relates to a manual acoustic axis aligning method for an ultrasonic sound field measuring system. The method comprises: obtaining an intersection between a current acoustic axis and a plane by scanning two detection planes, and calculating an inclination angle of the current acoustic axis; judging whether the inclination angle is less than an adjustment threshold. The method does not depend on the specific mechanical implementation of adjusting an acoustic axis angle. The iterative algorithm combined with geometric information can converge quickly. The criterion of intersection between the acoustic axis and the plane used is not limited to the amplitude criterion, and other criteria can be introduced by increasing the distance between two planes to increase the robustness of measuring the acoustic axis angle.

Apparatus and techniques are disclosed relating to a two-axis sensing element. In various embodiments, a two-axis sensing element includes a mounting plate that includes a first pair of mounting slots oriented in a first direction and a second pair of mounting slots oriented in a second, different direction. Further, in various embodiments, the two-axis sensing element may include a first pair of bender elements and a second pair of bender elements. The first pair of bender elements may be mounted through the first pair of mounting slots such that the first pair of bender elements is oriented in the first direction and the second pair of bender elements may be mounted through the second pair of mounting slots such that the second pair of bender elements is oriented in the second, different direction. In various embodiments, the mounting plate may transect each of the bender elements into two cantilever portions.

A method for managing a target location of at least a first vessel in a seismic survey involving at least one vessel, the first vessel performing a series of shoots according to a predefined set of shot points, called preplot. The method includes, during at least a part of the survey, computing an updated position of the center of the target location for the first vessel, using the trend, as a function of time, of a curve representing a time prediction shift for a shot point, for the first vessel, and depending on at least one parameter related to the capabilities of a vessel involved in the seismic survey.

The present disclosure provides optical link management in a marine seismic environment. A first device can transmit, to a second device, a first optical transmission at a first output level. The first optical transmission can include a first packet corresponding to a network protocol. The first device can determine that the second device failed to receive the first packet via the first optical transmission. The first device can transmit, responsive to failure of the first optical transmission, a second optical transmission at a second output level different than the first output level. The second optical transmission can include a second packet corresponding to the network protocol. The first device can identify that the second packet was successfully received by the second link manager agent. The first device can establish, responsive to the identification that the second packet was successfully received, the second output level as a transmission output level for the first device.

A marine seismic source includes source elements configured to emit waves having different frequencies while the source elements are towed at different predetermined depths, respectively. The predetermined depths are calculated such that water-surface reflections of the waves generated by a source element among the source elements interfere constructively with the waves generated by the source element and propagating toward an explored structure under the seafloor. The waves combine to yield a spike-like signature of the source.

Device, system and method for protecting towed marine survey equipment from line entanglement are provided. A cutter device has a mounting mechanism configured to fixedly attach at a predetermined position along a cable used for towing, and one or more cutting structures. The cutting structures are attached to and extend away from the mounting mechanism, being configured to cut lines that get caught by the cutting structures or slide along the cable to the predetermined position.

A system includes an unmanned marine vessel having a hull; a multi-dimensional seismic sensor array coupled with the hull, wherein the multi-dimensional seismic sensor array is configured to acquire seismic survey data in multiple directions; wherein the unmanned marine vessel comprises a power source configured to drive and provide propulsion to the unmanned marine vessel; and an umbilical cord for coupling the multi-dimensional seismic sensor array with the hull of the unmanned marine vessel, wherein the umbilical provides electrical communication between the unmanned marine vessel and the multi-dimensional seismic sensor array.

Disclosed are devices and methods for marine geophysical surveying. An example device may comprise a shell, a base plate, wherein the base plate is coupled to the shell, a driver disposed within the shell, an inner spring element disposed within the shell, wherein the inner spring element is coupled to the driver, wherein outer ends of the inner spring element are coupled to outer ends of the inner spring element at spring element junctions, an outer spring element disposed within the shell, wherein outer ends of the outer spring element are coupled to the spring element junctions, and a back mass disposed on the outer spring element.

Disclosed are control systems for marine vibrators. An example method may comprise recording a signal at a seismic sensor; running an iterative learning control characterization for a marine vibrator on the signal from the seismic sensor; measuring movement of an outer shell of the marine vibrator using a motion sensor to obtain a motion sensor signal; and controlling the marine vibrator using the motion sensor signal as a reference signal.