Methods, systems, and apparatuses are disclosed for sensing acoustic waves in a medium. One example system includes a first elongated member, a first motion sensor sensitive to vibrations of the first elongated member, a second motion sensor spaced apart from the first motion sensor and also sensitive to vibrations of the first elongated member, and a first vibration source operably coupled to the first elongated member and configured to vibrate the first elongated member.

So-called “Popcorn shooting”, and especially continuous Popcorn shooting, combined with simultaneous source shooting allows considerable flexibility in producing high-resolution data and in creating source arrays. Using a combination of simultaneous source de-blending and Popcorn reconstruction it is possible to construct using post acquisition processing arrays of any desired length by constructing a popcorn pattern that takes into account the vessel speed and physical arrangement of guns behind the towing vessel.

A system for surveying the structure beneath the seabed, comprising: a survey vessel; a streamer comprising a cable, a first set of N1 sensor groups positioned at a first end portion of the cable, the sensor groups of the first set being spaced from each other by a group interval, and a second set of N2 sensor groups positioned at a second end portion of the cable, the sensor groups of the second set being spaced from each other by the group interval; a sound source; wherein, when the system is in use, the survey vessel travels at a predetermined speed, towing the streamer and the sound source such that the sound source is positioned adjacent an intermediate portion of the cable between the first and second end portions of the cable; the sound source sends acoustic pulses at a predetermined period between pulses towards the seabed such that reflections are produced towards both the first set of sensor groups and the second set of sensor groups; and the speed of the survey vessel and the predetermined period of the sound source are selected such that the shot point interval of the sound source equals the group interval.

A system for deploying sonar for surveying in deep water includes a submerged movable platform deployed in the deep water at a depth below a thermocline and surface wave action, a propulsion mechanism for moving the platform through the water in a controlled manner, and a multibeam echosounder attached to the platform, wherein the echosounder includes a Mills Cross transmitter and receiver array. A method for deploying sonar for surveying in deep water comprises deploying a submerged movable platform in the deep water at a depth below a thermocline and surface wave action, employing a propulsion mechanism for moving the platform through the water in a controlled manner, and employing a multibeam echosounder attached to the platform, wherein the multibeam echosounder comprises a Mills Cross transmitter and receiver array.

Presented are methods and systems for collecting marine seismic data. The collected seismic data can be low frequency (e.g., less than 10 Hz) or it can be a full seismic bandwidth (1-200 Hz) depending on if the low frequency tuned sources and tuned receivers are combined with conventional sources and receivers. The low frequency sources can be towed or they can be autonomous and positioned in the survey area by tether, drifting or self-propelled. The tuned low frequency receivers are towed at a depth greater than conventional receivers and the sources can be fired independently or simultaneously.

A method for seismic surveying comprises deploying a plurality of seismic receivers proximate an area of subsurface to be surveyed. At least one seismic energy source moves in a path that circumscribes a center, wherein positions of the plurality of seismic receivers remain fixed. At least one of a distance between the path and the center changes monotonically as seismic energy source traverses the path, or the center moves in a selected direction as the seismic energy source traverses the path. The source is actuated at selected times as the at least one seismic energy source traverses the path, such that a spacing between positions of the source along the source path and transverse to the source path varies between successive actuations of the source. Seismic energy is detected at the plurality of seismic receivers resulting from actuating the at least one seismic energy source.

A method for seismic surveying comprises deploying a plurality of seismic receivers proximate an area of subsurface to be surveyed. At least one seismic energy source moves in a path that circumscribes a center, wherein positions of the plurality of seismic receivers remain fixed. At least one of a distance between the path and the center changes monotonically as seismic energy source traverses the path, or the center moves in a selected direction as the seismic energy source traverses the path. The source is actuated at selected times as the at least one seismic energy source traverses the path, such that a spacing between positions of the source along the source path and transverse to the source path varies between successive actuations of the source. Seismic energy is detected at the plurality of seismic receivers resulting from actuating the at least one seismic energy source.

Seismic node systems can be configured for acquiring seismic sensor data with an array of seismic receivers or nodes deployable in a survey area, each receiver or node having a seismic sensor for acquiring the seismic sensor data, a clock, a controller and local memory. The seismic sensor can data characterize a seismic wavefield proximate the seismic receivers in the survey area. Quality control data can be generated based on the seismic sensor data and associated timing information provided by the respective clock, and incorporated into a seismic data flow for recording in the local memory.

Marine survey source route configuration can include towing, via a first marine survey vessel, streamers at a first average speed and at an average velocity along a first survey route. A second marine survey vessel can tow a source at a second average speed that is greater than the first average speed along a second survey route that periodically passes over the first survey route and at the average velocity in a direction of the first survey route.

In one embodiment, a reverse time migration module is configured with a visco-acoustic wave equation for media with heterogeneous attenuation solved using a pseudo-analytical method. Seismic data is obtained for a zone of interest, and a model is created for the zone of interest. The model has spatial variability in velocity and quality factor. Pseudo-analytic Q-compensating reverse time migration (PA-Q-RTM) is performed using the reverse time migration module and the model for the zone of interest to obtain PA-Q-RTM seismic data. In another embodiment, a system for processing seismic data includes a reverse time migration module configured with a visco-acoustic wave equation that is solved from the pseudo-analytical method. The system operates to obtain seismic data for a zone of interest and perform PA-Q-RTM using a model for the zone of interest to obtain PA-Q-RTM seismic data for the zone of interest. Other embodiments and features are also disclosed.