Abstract: A subscriber station for a serial bus system. The subscriber station has a communication control device for controlling a communication of the subscriber station with at least one other subscriber station of the bus system, a transmitting/receiving device for transmitting a transmission signal in a frame on a bus of the bus system, and a scheduling unit for scheduling a temporal access of the subscriber station to the bus in at least one time slot of a cycle of temporally consecutive time slots, at least one time slot being provided in a cycle for each subscriber station for transmitting its transmission signal and the cycle repeating cyclically. The scheduling unit is designed to determine an assignment that specifies which time slot of the cycle the transmitting/receiving device is allowed to use for transmitting the frame for the transmission signal on the bus.

Abstract: Systems and methods for seismic data acquisition employing a dynamic multiplexing technique. The dynamic multiplexing technique may include advancing one or more modules in a seismic array through a multiplexing signature sequence in successive transmission periods. The multiplexing signature sequence may be random or pseudo-random. A shared multiplexing signature sequence may be used at all the modules in the seismic array. As such, modules belonging to a common collision domain may operate out of phase with respect to the shared multiplexing signature sequence.

Abstract: Systems and methods for seismic data acquisition utilizing wireless modules to perform real time data read out. The wireless modules may be assigned a shared multiplexing sequence through which each module advances in successive transmission periods. Wireless modules belonging to a shared collision domain may be operated out of phase from one another with respect to the shared multiplexing signature sequence. As such, a dynamic multiplexing regime may be implemented. The shared multiplexing signature sequence may include, among others, a plurality of different frequencies, a plurality of different codes, or a plurality of different discrete time periods.

Abstract: Systems and methods for seismic data acquisition utilizing wireless modules to perform real time data read out. The wireless modules may be assigned a shared multiplexing sequence through which each module advances in successive transmission periods. Wireless modules belonging to a shared collision domain may be operated out of phase from one another with respect to the shared multiplexing signature sequence. As such, a dynamic multiplexing regime may be implemented. The shared multiplexing signature sequence may include, among others, a plurality of different frequencies, a plurality of different codes, or a plurality of different discrete time periods.

Abstract: Systems and methods for seismic data acquisition with location aware network nodes. Based on location information of the nodes of the network, a multiplexing signature may be provided for the node. The location information may be used in conjunction with other information (e.g., location information of other nodes in the network and transmission ranges for nodes in the network) to determine collision domains. A multiplexing signature may be assigned to a node based on information regarding a collision domain to which the node belongs. As such, the assigned multiplexing signature may be used to avoid data collisions.

Abstract: A system includes a subterranean survey data acquisition network and a processor. The network has first nodes that are distributed along a length of the network between a first end of the network and a second end of the network. Each of the first nodes is capable of being either in a state in which the first node is transparent to the network or in a state in which the first node is visible to the network. The processor is adapted to communicate with the closest visible first node relative to the first end, and the processor is adapted to, based on the communication, determine whether the closest visible first node is the closest first node of all of the first nodes relative to the first end.

Abstract: A method of event-based power management for seismic sensors is disclosed. The method comprises measuring seismic activity with a seismic sensor and comparing the measured seismic activity from the seismic sensor against at least one criteria. When the measured seismic activity does not satisfy the at least one criteria, a signal processing circuit is maintained in a deactivated state. When the measured seismic activity satisfies the at least one criteria, the signal processing circuit is activated to analyze the measured seismic activity. The signal processing circuit enters a functional mode based on analyzing the measured seismic activity.

Abstract: Systems and methods for seismic data acquisition employing a dynamic multiplexing technique. The dynamic multiplexing technique may include advancing one or more modules in a seismic array through a multiplexing signature sequence in successive transmission periods. The multiplexing signature sequence may be random or pseudo-random. A shared multiplexing signature sequence may be used at all the modules in the seismic array. As such, modules belonging to a common collision domain may operate out of phase with respect to the shared multiplexing signature sequence.

Abstract: A seismic data acquisition method is provided that includes receiving seismic signals at a sensor; sampling the received seismic signals into a plurality of samples, each sample having a selected number of bits (“bit length”); arranging the samples in packets, wherein some of the packets include one or more compressed samples; and transmitting the packet to a remote unit.

Abstract: Systems and methods are provided for acquiring seismic data using a wireless network and a number of individual data acquisition modules that are configured to collect seismic data and forward data to a central recording and control system. In one implementation, a number of remote modules (301) are arranged in lines. Base station modules (302) receive information from the lines and relay the information to a central control and recording system (303). Radio links operating on multiple frequencies (F1-F12) are used by the modules (301). For improved data transfer rate, radio links from a remote module (301) leap past the nearest remote module to the next module closer to the base station.

Abstract: A system capable of operation with dynamic sockets includes a plurality of communications devices. Each of the plurality of communications devices includes high band channel radio resources capable of communications at 900-2800 MHz and socket radio resources capable of communications at 30-1000 MHz. The high band channel radio resources and the socket radio resources are significantly separated in frequency so that the high band channel radio resources and the socket radio resources are suitable for concurrent operation with no interference and minimal isolation, co-site problems to solve in each of the plurality of communications devices. The plurality of communications devices are connected to a unifying mesh network by the high band channel radio resources. The unifying mesh network is suitable for allowing the plurality of communications devices to communicate with one another.

Abstract: A network distributed seismic data acquisition system comprises seismic receivers connected to remote acquisition modules, receiver lines, line tap units, base lines, a central recording system and a seismic source event generation unit synchronized to a master clock. One or more high precision clocks is added to the network to correct for timing uncertainty associated with propagation of commands through the network. Seismic receivers and seismic sources are thereby synchronized with greater accuracy than otherwise possible. Timing errors that interfere with the processing of the seismic recordings are greatly reduced, thus enabling an improvement in subsurface geologic imaging.

Abstract: An apparatus and method for collecting data acquired during a seismic survey are disclosed. The apparatus is a seismic survey system, comprising a plurality of data sources, a plurality of cells, and a plurality of independent pathways. The data sources are positioned about an area to be surveyed, each data source being associated with a transmitter capable of transmitting data. The cells each contain a portion of the data sources and their associated transmitters. One of the transmitters within each cell also serves as a gateway for receiving data transmitted from the other data source transmitters within the cell. The independent pathways each contain a portion of the gateways whereby data may be transmitted along each pathway via the gateways and associated transmitters in that pathway. The method is a method for conducting a seismic survey.

Abstract: A network distributed seismic data acquisition system comprises seismic receivers connected to remote acquisition modules, receiver lines, line tap units, base lines, a central recording system and a seismic source event generation unit synchronized to a master clock. One or more high precision clocks is added to the network to correct for timing uncertainty associated with propagation of commands through the network. Seismic receivers and seismic sources are thereby synchronized with greater accuracy than otherwise possible. Timing errors that interfere with the processing of the seismic recordings are greatly reduced, thus enabling an improvement in subsurface geologic imaging.

Abstract: A seismic survey system having remote acquisition modules (RAMs) for acquiring seismic signals and communicating with a central recording system (CRU) via a network of cables, other RAMs, and line tap units (LTUs), arranged in a matrix of receiver lines and base lines. Each RAM cyclically converts analog signal values to digital, forming data packets. Interrogation commands emanating from the CRU and relayed with strategic delays by intervening LTUs and RAMs are received by the RAM. Each command causes the RAM to transmit a data packet. Strategic delays are set such that the transmission capacity of the line is best utilized. Power and frequency of transmission are selectable by the CRU to optimize performance. Cables contain multiple communication pairs. The network path between the RAM and the CRU is established from the CRU and altered in event of malfunction. All types of network elements are interconnectable. Recorded samples are synchronous.

Abstract: A seismic survey system having remote acquisition modules (RAMs) for acquiring seismic signals and communicating with a central recording system (CRU) via a network of cables, other RAMs, and line tap units (LTUs), arranged in a matrix of receiver lines and base lines. Each RAM cyclically converts analog signal values to digital, forming data packets. Interrogation commands emanating from the CRU and relayed with strategic delays by intervening LTUs and RAMs are received by the RAM. Each command causes the RAM to transmit a data packet. Strategic delays are set such that the transmission capacity of the line is best utilized. Power and frequency of transmission are selectable by the CRU to optimize performance. Cables contain multiple communication pairs. The network path between the RAM and the CRU is established from the CRU and altered in event of malfunction. All types of network elements are interconnectable. Recorded samples are synchronous.

Abstract: A seismic survey system having remote acquisition modules (RAMs) for acquiring seismic signals and communicating with a central recording system (CRU) via a network of cables, other RAMs, and line tap units (LTUs), arranged in a matrix of receiver lines and base lines. Each RAM cyclically converts analog signal values to digital, forming data packets. Interrogation commands emanating from the CRU and relayed with strategic delays by intervening LTUs and RAMs are received by the RAM. Each command causes the RAM to transmit a data packet. Strategic delays are set such that the transmission capacity of the line is best utilized. Power and frequency of transmission are selectable by the CRU to optimize performance. Cables contain multiple communication pairs. The network path between the RAM and the CRU is established from the CRU and altered in event of malfunction. All types of network elements are interconnectable. Recorded samples are synchronous.

Abstract: A seismic survey system having remote acquisition modules (RAMs) for acquiring seismic signals and communicating with a central recording system (CRU) via a network of cables, other RAMs, and line tap units (LTUs), arranged in a matrix of receiver lines and base lines. Each RAM cyclically converts analog signal values to digital, forming data packets. Interrogation commands emanating from the CRU and relayed with strategic delays by intervening LTUs and RAMs are received by the RAM. Each command causes the RAM to transmit a data packet. Strategic delays are set such that the transmission capacity of the line is best utilized. Power and frequency of transmission are selectable by the CRU to optimize performance. Cables contain multiple communication pairs. The network path between the RAM and the CRU is established from the CRU and altered in event of malfunction. All types of network elements are interconnectable. Recorded samples are synchronous.

Abstract: A seismic survey system having remote acquisition modules (RAMs) for acquiring seismic signals and communicating with a central recording system (CRU) via a network of cables, other RAMs, and line tap units (LTUs), arranged in a matrix of receiver lines and base lines. Each RAM cyclically converts analog signal values to digital, forming data packets. Interrogation commands emanating from the CRU and relayed with strategic delays by intervening LTUs and RAMs are received by the RAM. Each command causes the RAM to transmit a data packet. Strategic delays are set such that the transmission capacity of the line is best utilized. Power and frequency of transmission are selectable by the CRU to optimize performance. Cables contain multiple communication pairs. The network path between the RAM and the CRU is established from the CRU and altered in event of malfunction. All types of network elements are interconnectable. Recorded samples are synchronous.

Abstract: The present invention provides a method and apparatus of acquiring and processing seismic data. One or more controllers are each coupled to seismic sensors and to each other to form a network of data acquisition units. A main controller is coupled to a crossline unit via a cable comprising a synchronizing conductor and one or more power/data conductors. Commands and data are packaged such that multiple routings are possible without affecting final calculations. Each crossline unit is capable of accepting a fiber optic input, a wire input or a combination.

Abstract: A method and system for interrogating a seismic sensor in a seismic cable having modular sensing stations spaced along the seismic cable and a connection module head end of the sensor sections, that includes dropping, at the connection modules, a wavelength of light from an input bus telemetry fiber that includes multiple wavelengths of light, distributing the dropped wavelength of light to the seismic sensor, returning the dropped wavelength from the seismic sensor to a return telemetry fiber, remultiplexing the dropped wavelength of light onto the return bus telemetry, and amplifying, in the seismic cable, the returned dropped wavelength.

Abstract: A method and device for seismic exploration of a subsea geologic formation by pickups set on the sea bottom and intermittently connectable to active data acquisition stations (11) brought nearby. Permanent passive reception stations (1) comprising a heavy pedestal provided with housings for seismic pickups (geophones (6), hydrophone (7) which receive acoustic or seismic signals from the underlying formation are arranged at the bottom of the water body. When collection sessions for the signals received by the pickups are scheduled, mobile active acquisition stations (11) connected to permanent passive reception stations (1) are positioned at the bottom of the water body. The signals picked up are then recorded, for the time required to carry out at least one session of acquisition and recording of the acoustic or seismic signals received by the passive stations in response to the emission of seismic waves by one or more seismic sources.

Abstract: An apparatus, system, and method are provided for interrogating of optical seismic sensors in a seismic cable. According to various example embodiments of the invention, distribution, return, and amplification of optical signals is performed near sensors for improvement of modularity of construction, signal-to-nose ratios, and simplicity of operations.

Abstract: An apparatus and method are provided for ensuring good coupling and vertically planting of seismic receivers while substantially reducing the need for interconnecting wires and costly surveys. The apparatus includes an acquisition unit (AU) 20 for measuring seismic energy and a planting member 12 for engaging and planting the AU 20. An electronic surveying instrument 14 is coupled to the planting member 12 for determining the location of the AU 20. An installer 16 plants the AU 20 in the terrain 22 in near vertical alignment using the planting member 12. Once the AU 20 is planted in near vertical alignment, coordinates are downloaded from the electronic survey unit to locate the planted AU 20.

Abstract: An efficient method for evaluating static corrections based upon molecular dynamics simulation. This approach combines the global minimization mechanism of simulated annealing and the deterministic approach of molecular dynamics simulation and finds the surface-consistent source and receiver static corrections by minimizing the objective function. The objective function is a measure of the reflection coherency of the whole data set.

Abstract: In a well logging tool forming a data stream for telemetry to the surface, an encoding system is located downhole cooperative with surface located decoding equipment. The encoder converts serial data into NRZ symbols, then duobinary code of seven levels and then into quadrature modulating signals on a complex carrier. The decoder at the well surface receives the quadrature modulated complex carrier, forms inphase and quadrature components and decodes the two components. The decoder includes circuit means removing the intersignal distortion and also intersymbol smearing. This enables very significant telemetry ratio.

Abstract: A seismic recording system comprises a multichannel recorder connected to a cable formed from a plurality of signal conductors. Each of the signal conductors is connected to a different channel of the recorder. The cable has a plurality of takeouts located at spaced distances along its length. Each of the takeouts is connected to a different signal conductor of the cable. The system further includes a first conduit operably connected to one of the takeouts. A plurality of remotely operable switch means are located along the length of the first conduit for selectively interconnecting the first conduit and a plurality of detector conduits upon receipt of a remotely generated signal. Each detector conduit has at least one geophone located along its length and operably connected thereto. A control means is provided for transmitting a signal to a selected switch means for interconnecting its associated detector conduit and geophones with the recorder.

Abstract: Method and device for the high-rate transmission of data between a multiplicity of acquisition apparatuses (Ai) and a central station to which they are connected by a common transmission channel (V1) for commands and by a high-rate transmission channel (V2) for data.A first clock signal (H1) serves for the transmission of the orders, the acquisition of the data and their storage in a memory (10). A second clock signal (H2) with a higher frequency non synchronous with the first one is used for reading the data stored by each acquisition apparatus. A determined time interval (or window) is assigned to each apparatus and the reading of each stored sample is activated by an order signal indicating the beginning of this window.Application to a seismic transmission system for example.

Abstract: A digital marine seismic system employes a plurality of data acquisition control modules which simultaneously digitize analog seismic signals. The control modules also are selectably addressable in that each module is uniquely programmed to respond only to a particular control word. The system allows a large number of channels, such as 480 channels, on a simple transmission system, such as a twisted pair of wires. Each module includes a power switch to sequentially apply power to downstream modules. Selective addressing of the switches allow testing of specific modules for power malfunctions.

Abstract: A real time seismic telemetry system includes a central station (10) for communication with a plurality of remote data acquistion units (14). The command station (10) has a command unit (34) for controlling the operation of a transmitter (40) for providing instructions to the data acquistion units (14). The data acquistion units (14) receive the data on a receiver (80) and process the data in a logic control circuit (88). Remote data is picked up with a hydrophone (30) and converted to digital data for transmission through a transmitter (78) which is tuned to a discrete channel for each data acquistion unit (14). The command station (10) has a PCM receiver (62) tuned to each of the channels for demodulating the data stream therefrom. A digital receiver (66) is provided for synchronizing and processing the data. The digital receiver (66) synchronizes both to the bit rate and to the beginning and ending of the digital word such that data contained in the digital word can be multiplexed onto a data bus (68).

Abstract: Transmitting information from a central receiver and recorder utilizes plural series-connected transmission modules, each connected to a respective data acquisition unit. The transmission modules are sequentially connected along plural transmission lines, at least two of which are outgoing data transmission lines for transmitting information from the central receiver and recorder to the acquisition units. At least two other lines are incoming data transmission units to the central receiver and recorder. Each transmission module has, for each outgoing line, respective line receivers, informaiton decoders, line transmitters and matrices of transmission line selectors controlled by individual information decoders, and a selector unit which ensures that a signal from a selected outgoing transmission line is transmitted to the next module on all outgoing transmission lines.

Abstract: A submersible well pump has a system for monitoring parameters such as pressure and temperature in the vicinity of the motor. The system includes a downhole assembly in the well that has a transmitter for generating a carrier signal and superimposing that signal onto the power cable. Transducers in the downhole assembly sense physical parameters and provide a change in resistance corresponding to the physical parameters. These transducers are connected to a modulator which modulates the carrier signal according to the resistance. A shift register in the downhole assembly sequentially shifts a reference resistor and two or more transducers into the modulating circuit to provide envelopes on the carrier signal corresponding to a synchronizing signal and to data being sensed. The modulated carrier signal is demodulated at the surface into separate channels, where each can provide a readout proportional to the physical parameter sensed.

Abstract: Device for the sequential transmission of signals by radio or by cable between a central control and recording station and local data acquisition apparatuses, comprising cables connecting said data acquisition apparatuses to the central station and radio transmission and reception means associated with each acquisition apparatus and with the central station, and switching means for establishing the cable connection and interrupting the radio connection between the central station and any particular apparatus for which said radio connection becomes defective as a result of obstacles on the path between the location of said apparatus and that of the central station.

Abstract: The interface between a computer and a solid state mass memory is provided by an electronic circuit wherein data is rearranged. Data may be received in multiplexed or unmultiplexed form. The disclosed electronic circuit assigns address locations using three parameters, a starting location parameter, an increment value parameter and an increment repetition parameter to permit nonsequential addressing or memory location skipping.

Abstract: A cable system for carrying out seismic operations, comprising a multi-conductor cable built with multiple segments, each segment terminated with identical connector plugs. Each segment having a selected number P of take-outs for accepting P seismic signals. The group of P seismic signals from the take-outs are multiplexed in each cable segment, and travel over a single conductor pair in the successive segments to the recording truck, where they are demultiplexed, and as reconstituted signals, are processed and recorded.

Abstract: The digital output telemetering system for recording seismic signals comprises, according to the invention, a seismic channels commutator connected to an instantaneous automatic gain controller whose outputs are connected to an input of an analog memory and to inputs of a decoder. The latter has its two other inputs connected to a trigger output and a calibration output, respectively, of a unit for controlling a digital-analog converter. Outputs of the decoder are respectively connected to an input of an AND gate, a reset input of a counter and a second, control, input of the analog memory whose output is connected to an analog-digital converter. The latter has its output connected to an input of a receiving register whose other inputs are respectively connected to an output of a single-digit counter and an input of the decoder. The instantaneous automatic gain controller comprises two single-digit memories connected to a second input of the analog memory and to a second input of the decoder, respectively.

Abstract: A seismic cable connector is provided for use with a dual fiber cable in a fiber optic seismic exploration system. The connector contains a digital transceiver which includes an optical detector connected to one fiber of the cable and a fiber optic transmitter connected to the other fiber. The digital transceiver is housed in an environmentally sealed case to protect the transceiver and the ends of the optical fibers from being affected or damaged during use in the field. The transceiver is activated by transistor-transistor logic contained within the connector. The optical fibers are protected by buffer tubes extending the length of the cable. A sixty-one pin electrical plug is provided in the cable connector for mating the connector with remote seismic data gathering units.

Abstract: A data acquisition and transport system including a plurality of array terminals, each array terminal having a plurality of geophones delivering analog signals thereto, the analog signals being digitized to 1-bit and temporarily stored, and on demand, transmitted downline to a recording station, as a train of 1-bit pulses. The array terminals have two identical ports into which cable segments of two conductor digital transmission channels can be plugged. Means are provided in the recording station to place a DC potential between the two terminals of the digital transmission channel. In the array terminals means are provided for identifying which of the two identical ports is the one which receives the DC potential, which is identified as the downline port. On receiving a DC potential at the downline port, a corresponding DC potential is transmitted through the upline port to the next array terminal and so on.

Abstract: A seismic prospecting roll along switching system using a relatively small number of switches to provide roll along prospecting while also providing variable gapping with minimum loss of active channels. In a simple form two sets of switches are provided with each set having one switch provided for each geophone input and with switch outputs connected in pairs, appropriately selected, to the inputs of signal processing channels. The two sets of switches are connected to the processing channels in a skewed or staggered manner with the amount of skew corresponding to a selectable gap. A controller is provided for electronically closing the appropriate switches from each set in accordance with the desired gap. Additional switch sets may be employed to provide additional selectable gaps while maintaining complete utilization of processing channels.