Imperfect separation at the higher frequencies has been observed and was eventually was tracked down to the poor GFE signal that is normally used in the inversion. The invention thus uses a “derived GFE” for each source, obtained by comparing the shot records and remove the differences, instead of the prior estimated GFE signal put out by the controller, thus accurately maximizing the separation of the data.

A method is developed for dynamically configuring a network with numerous subnets, each subnet comprising at least one router node and said network comprising at least one subnet server. For enhancing the efficiency, the determination of a subnet master for configuring a subnet is carried out with two parallel processes: election of a subnet master among the router nodes of said subnet allocation to each router node of said subnet of a subnet identifier. Configuration of the subnet, achieved by the subnet master with its allocated subnet identifier, is refreshed regularly, in particular when detecting a change in the configuration of the network.

A rock breaking seismic source and active source three-dimensional seismic combined detection system uses a tunnel boring machine for three-dimensional seismic combined detection by active seismic source and rock breaking seismic source methods. Long-distance advanced prediction and position recognition of a geological anomalous body are realized using the active source seismic method. Machine construction is adjusted and optimized according to the detection result; real-time short-distance accurate prediction of the body is realized using the cutter head rock breaking vibration having weak energy but containing a high proportion of transverse wave components as seismic sources and adopting an unconventional rock breaking seismic source seism recording and handling method. An area surrounding rock quality to be excavated is represented and assessed. A comprehensive judgment is made to the geological condition in front of the working face with the results of active source and rock breaking seismic source three-dimensional seismic advanced detection.

A method is described for analysis of subsurface data including the use of physics-based modeling and experimental design that allows calculation of probabilities of physical subsurface properties. The method may include calculations of key controlling parameters. The method may include using multiple dimension scaling. The method may be executed by a computer system.

A system includes a memory configured to store a first acoustic profile associated with a device. The first acoustic profile includes at least two of the following acoustic characteristics: frequency, amplitude, and time. The system further includes a processor communicatively coupled to the memory and an acoustic sensor. The processor is configured to receive, from the acoustic sensor, an acoustic signal comprising one or more of the frequency and amplitude, compare the received acoustic signal to the first acoustic profile, and determine that the received acoustic signal matches the first acoustic profile based on the comparison of the received acoustic signal to the first acoustic profile.

Method for acquiring, at reduced acquisition cost, seismic data using simultaneous, field-encoded sources in the field (702), and then constructing pseudo source-records (703) that better meet the requirements for using additional simultaneous computer-encoded sourcing for computer simulations or forward modeling (706) as part of (707) iterative FWI (Full Wavefield Inversion) or RTM (Reverse Time Migration), with additional reduction in computational costs. By better meeting the requirements of simultaneous sourcing for FWI or RTM (701), artifacts and crosstalk are reduced in the output. The method can be used for marine streamer acquisition and other non-fixed spread geometries to acquire both positive and negative offsets and to mitigate the “missing data” problem for simultaneous-source FWI. It can also be used for land data to overcome issues with moving spreads and long continuous records.

Various examples are provided for land streamer seismic surveying using multiple sources. In one example, among others, a method includes disposing a land streamer in-line with first and second shot sources. The first shot source is at a first source location adjacent to a proximal end of the land streamer and the second shot source is at a second source location separated by a fixed length corresponding to a length of the land streamer. Shot gathers can be obtained when the shot sources are fired. In another example, a system includes a land streamer including a plurality of receivers, a first shot source located adjacent to the proximal end of the land streamer, and a second shot source located in-line with the land streamer and the first shot source. The second shot source is separated from the first shot source by a fixed overall length corresponding to the land streamer.

A method of redatuming geophysical data, wherein there is provided multi-component geophysical data, and the method includes obtaining at least one focussing function and/or at least one Green's function from the multi-component geophysical data.

An embodiment of a method of performing aspects of a downhole operation includes receiving a measurement value from a first sensor configured to measure a parameter related to the downhole operation, receiving measurement data from a different sensor, the measurement data related to the downhole operation, and performing, by a sensor evaluation module, an evaluation of the first sensor. The evaluation includes determining a condition of the first sensor based on the measurement data from the different sensor, selecting a rule that prescribes a set of one or more measurement values of the parameter that are plausible if the condition is met, and determining whether the measurement value from the first sensor is plausible based on comparing the measurement value to the prescribed set of one or more measurement values.

An embodiment of a method of performing aspects of a downhole operation includes receiving a measurement value from a first sensor configured to measure a parameter related to the downhole operation, receiving measurement data from a different sensor, the measurement data related to the downhole operation, and performing, by a sensor evaluation module, an evaluation of the first sensor. The evaluation includes determining a condition of the first sensor based on the measurement data from the different sensor, selecting a rule that prescribes a set of one or more measurement values of the parameter that are plausible if the condition is met, and determining whether the measurement value from the first sensor is plausible based on comparing the measurement value to the prescribed set of one or more measurement values.