Abstract: A method for synchronizing signals of a plurality of participants. A relationship between the signals is given by a physical relation. The signals are each filtered with a first filter in order to determine a shift between the signals. The determined shift is a measure of the phase shift between the signals. The shift is subsequently eliminated by filtering the signals respectively with a second filter.

Abstract: A system, a method and an autonomous network for vibration monitoring, the system comprising a master station preset for recording vibrations at a master trigger threshold; a secondary station, the secondary station and the master station being time synchronized, a server in communication with the master and secondary stations; wherein, the master station is configured to transmit a master trig time to the server and to start recording vibrations when the master trigger threshold is exceeded; the server is configured to store the master trig time; the secondary station is configured to detect the master trig time stored by the server, and upon detecting the master trig time, to record vibrations; and wherein the master and secondary stations are configured to transmit respective recorded vibrations to the server and the server is configured to classify the recorded vibrations in relation to a preset seismic threshold.

Abstract: A roaming method based on MESH WIFI executable by an electronic device, comprising: calculating noise values and interference coefficients of a primary access point (AP) and surrounding APs, adjusting power values between the primary AP and the surrounding APs based on the noise values and the interference coefficients according to normalization, and, when a target AP from the surrounding APs reaches a preset condition, switching the client to connect to the target AP.

Abstract: A method for optimizing power supply life time of an industrial sensor platform which includes a processing unit, a power supply, and transmission means. The method identifies a sensor connected to an industrial platform, verifies a functional setting of the platform, determines sensor power consumption and sensor measurement time ts, and determines transmission power consumption of the transmission means. The method further includes acquiring input parameter settings which includes expected battery life time, sensor reading interval Ts and periodic transmission interval Tw. Which is followed by calculating an optimum for power supply life time, sensor reading interval Ts, and periodic transmission interval Tw. And adjusting settings of the platform for sensor reading interval Ts and periodic transmission interval Tw according to the optimum calculated.

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 are arranged in lines. Base station modules receive information from the lines and relay the information to a central control and recording system. Radio links operating on multiple frequencies are used by the modules. 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. Modules belonging to a common collision domain may operate out of phase with respect to the shared multiplexing signature sequence.

Abstract: Apparatuses, systems, and methods for use of directionalized antennas at a seismic module in a seismic survey array. The directionalized antenna may be selectively controlled such that the control of the transmission functionality and reception functionality are independently controlled to transmit data in and receive data from different directions. In turn, bandwidth utilization may be improved in the survey. Additionally, the directionalized antennas may allow for simultaneous transmission and reception of data in a serial data transfer line.

Abstract: A cableless seismic acquisition system that is configured to resolve the locations of a plurality of cableless seismic acquisition units (e.g., up to 1,000,000 or more) of the system at sub-meter levels of accuracy (e.g., less than 10 cm, less than 5 cm, etc.) free of many of the limitations of existing manners of determining cableless unit locations in seismic acquisition systems. While accurately determining cableless unit locations for use in mapping underground structures of interest, the disclosed cableless seismic acquisition system also limits power demands of and ultimately power consumption by the cableless units to extend serviceable deployment time of the cableless acquisition system.

Abstract: A disclosed seismic survey system includes one or more streamer(s) each having multiple spaced apart sensor units, and a data recording and control system. Each sensor unit receives a command from the data recording and control system, and operates in an enabled state or a disabled state dependent upon the command. The data recording and control system collects and stores data from enabled sensor units. The sensor units produce data when in the enabled state, and dissipate significantly less electrical power in the disabled state. A described sensor unit includes one or more sensor(s), an analog-to-digital converter, and a control unit that enables or disables the analog-to-digital converter dependent upon the command. A disclosed method for acquiring seismic survey data includes issuing an enable or disable command to each of multiple spaced apart sensor units, and receiving and storing data from those sensor units that are enabled.

Abstract: A communication method is provided in a communication network, including a plurality of devices forming an ordered communication segment. At least one intermediate device of this segment is connected to at most two other devices called a previous device and a next device. The intermediate device receives data from the previous device and emits at least these data to the next device to propagate the data on the segment. A concentrator initializes transmission of a first frame of data through the segment to a terminal device ending the segment, which sends back a symbol initiating transmission of a second frame of data to the first concentrator through the segment. The method includes receiving a first symbol from the previous device, which triggers emitting a WAIT symbol to the previous device and emitting at least first symbol to the next device.

Abstract: It is proposed a method for collecting, in a collecting device distinct from a central unit, data coming from a plurality of seismic acquisition units. The method includes a step of assigning at least one device as a sink unit. For a given sink unit, the method also includes the following steps for data specific to at least one seismic acquisition unit not assigned as a sink unit: transmitting the specific data from the at least one seismic acquisition unit to the given sink unit, via a radio path established in a radio multi-hop network built at least with the given sink unit and the plurality of seismic acquisition units; and transmitting the specific data from the given sink unit to the collecting device, via a link.

Abstract: The transmission system combines a self-contained, wireless seismic acquisition unit and a wireless, line of site, communications unit to form a plurality of individual short-range transmission networks and also a mid-range, line of sight transmission network.

Abstract: The transmission system combines a self-contained, wireless seismic acquisition unit and a wireless, line of site, communications unit to form a plurality of individual short-range transmission networks and also a mid-range, line of sight transmission network. Each seismic unit has a power source, a short-range transmitter/receiver disposed within a casing and a geophone disposed within the casing. Each wireless communications unit is formed of an elongated support structure on which is mounted an independent power source, mid-range radio transmitter/receiver; and a short-range transmitter/receiver configured to wirelessly communicate with the short-range transmitter/receiver of the acquisition unit. Preferably, when deployed, the acquisition unit is buried under the surface of the ground, while the wireless communications unit is positioned in the near vicinity of the buried unit so as to vertically protrude above the ground.

Abstract: An EHF communication system including an EHF communication chip. The EHF communication chip may include an EHF communication circuit having at least one controllable parameter-based module having a testable and controllable operating parameter The EHF communication chip may further include a test and trim circuit coupled to the EHF communication circuit, where the test and trim circuit includes a logic circuit having one or more memory elements, where the logic circuit is coupled to the controllable parameter-based module.

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: A buoy is configured to record seismic signals while underwater. The buoy includes a body; a buoyancy system configured to control a buoyancy of the body to descend multiple times to a predetermined depth (H) and then resurface with a controlled speed; and a seismic sensor located in the body and configured to record the seismic signals. The seismic sensor is instructed to record the seismic signals as the buoy travels up and down between the water surface and the predetermined depth.

Abstract: The present invention relates to a method for synchronizing continuous seismic survey. In particular, the present invention employs a semaphore scheme for the vibes to autonomously and continuously initiate sweeps, thereby decoupling the vibratory source subsystem from the recording subsystem. By using a continuous recorder and the method of the present invention, the recording trucks and the observers can be eliminated, and the vibratory sources can be initiated more efficiently than conventional systems.

Abstract: A method, system, and apparatus for communicating data with a seismic sensor are provided. The method comprises identifying data to be transmitted and one or more seismic events that correspond to the data to be transmitted. One or more seismic events are created that are distinguishable into binary code from one or more seismic sensors within the array. Seismic events can be distinguished by their pattern or frequency. A first frequency can be assigned as a first binary code and a second frequency can be assigned as a second binary code. Likewise, different patterns of acoustic energy can designate different binary codes. Combinations of patterns and frequencies can be used together to create distinct distinguishable seismic events.

Abstract: Embodiments of the present invention address deficiencies of the art in respect to positioning for geophysical sensing and provide a method, system and apparatus for rotary laser positioning in geophysical sensing. In an embodiment of the invention, a geophysical sensing data processing system can be provided to include multiple laser energy sources disposed about a target scene, and a mobile sensor unit. The mobile sensor unit can include at least one laser energy source sensor coupled to a laser positioning system, and one or multiple geophysical sensor communicatively linked to the laser positioning system. In one aspect of the invention, the laser positioning system can be a Rotary Laser Positioning System (RLPS). Complementary positioning sensors further can be provided.

Abstract: Presented are systems and methods for deploying wireless data acquisition modules that facilitate autonomous initialization. The wireless data acquisition modules may initiate a initialization process in response to a stimulus associated with being deployed. The wireless data acquisition module may further conduct a neighbor discovery process and in turn establish a data transfer path among one or more other wireless data acquisition modules. Further, information obtained during a series of autonomous tests may be communicated during the neighbor discovery process and the establishment of the data transfer path may at least in part be based on the information obtained in the autonomous tests.

Abstract: The transmission method utilizes multiple seismic acquisition units within an array as intermediate short range radio receivers/transmitters to pass collected seismic data in relay fashion back to a control station. Any one seismic unit in the array is capable of transmitting radio signals to several other seismic units positioned within radio range of the transmitting unit, thus allowing the system to select an optimal transmission path. Utilizing an array of seismic units permits transmission routes back to a control station to be varied as needed. In transmissions from the most remote seismic unit to the control station, each unit within a string receives seismic data from other units and transmits the received seismic data along with the receiving unit's locally stored seismic data. Preferably, as a transmission is passed along a chain, it is bounced between seismic units so as to be relayed by each unit in the array.

Abstract: The transmission method utilizes multiple seismic acquisition units within an array as intermediate short range radio receivers/transmitters to pass collected seismic data in relay fashion back to a control station. Any one seismic unit in the array is capable of transmitting radio signals to several other seismic units positioned within radio range of the transmitting unit, thus allowing the system to select an optimal transmission path. Utilizing an array of seismic units permits transmission routes back to a control station to be varied as needed. In transmissions from the most remote seismic unit to the control station, each unit within a string receives seismic data from other units and transmits the received seismic data along with the receiving unit's locally stored seismic data. Preferably, as a transmission is passed along a chain, it is bounced between seismic units so as to be relayed by each unit in the array.

Abstract: The transmission method utilizes multiple seismic acquisition units within an array as intermediate short range radio receivers/transmitters to pass collected seismic data in relay fashion back to a control station. Any one seismic unit in the array is capable of transmitting radio signals to several other seismic units positioned within radio range of the transmitting unit, thus allowing the system to select an optimal transmission path. Utilizing an array of seismic units permits transmission routes back to a control station to be varied as needed. In transmissions from the most remote seismic unit to the control station, each unit within a string receives seismic data from other units and transmits the received seismic data along with the receiving unit's locally stored seismic data. Preferably, as a transmission is passed along a chain, it is bounced between seismic units so as to be relayed by each unit in the array.

Abstract: The transmission method utilizes multiple seismic acquisition units within an array as intermediate short range radio receivers/transmitters to pass collected seismic data in relay fashion back to a control station. Any one seismic unit in the array is capable of transmitting radio signals to several other seismic units positioned within radio range of the transmitting unit, thus allowing the system to select an optimal transmission path. Utilizing an array of seismic units permits transmission routes back to a control station to be varied as needed. In transmissions from the most remote seismic unit to the control station, each unit within a string receives seismic data from other units and transmits the received seismic data along with the receiving unit's locally stored seismic data. Preferably, as a transmission is passed along a chain, it is bounced between seismic units so as to be relayed by each unit in the array.

Abstract: Systems and methods for utilization of a smart antenna in facilitating wireless communication between adjacent seismic data acquisition modules. The smart antenna may target an adjacent module with a radiation pattern directed toward the adjacent module. As such, the modules may employ space division multiplexing techniques to avoid interference between modules in the array. The modules may scan throughout a continuum of positions to locate adjacent modules. Once located, a spatial signal signature may be identified for the adjacent module and beamforming vectors may be calculated for targeting the radiation pattern toward the located module.

Abstract: The transmission system combines a self-contained, wireless seismic acquisition unit and a wireless, line of site, communications unit to form a plurality of individual short-range transmission networks and also a mid-range, line of sight transmission network.

Abstract: The transmission system combines a self-contained, wireless seismic acquisition unit and a wireless, line of site, communications unit to form a plurality of individual short-range transmission networks and also a mid-range, line of sight transmission network. Each seismic unit has a power source, a short-range transmitter/receiver disposed within a casing and a geophone disposed within the casing. Each wireless communications unit is formed of an elongated support structure on which is mounted an independent power source, mid-range radio transmitter/receiver; and a short-range transmitter/receiver configured to wirelessly communicate with the short-range transmitter/receiver of the acquisition unit. Preferably, when deployed, the acquisition unit is buried under the surface of the ground, while the wireless communications unit is positioned in the near vicinity of the buried unit so as to vertically protrude above the ground.

Abstract: The transmission method utilizes multiple seismic acquisition units within an array as intermediate short range radio receivers/transmitters to pass collected seismic data in relay fashion back to a control station. Any one seismic unit in the array is capable of transmitting radio signals to several other seismic units positioned within radio range of the transmitting unit, thus allowing the system to select an optimal transmission path. Utilizing an array of seismic units permits transmission routes back to a control station to be varied as needed. In transmissions from the most remote seismic unit to the control station, each unit within a string receives seismic data from other units and transmits the received seismic data along with the receiving unit's locally stored seismic data. Preferably, as a transmission is passed along a chain, it is bounced between seismic units so as to be relayed by each unit in the array.

Abstract: The transmission system combines a self-contained, wireless seismic acquistion unit and a wireless, line of site, communications unit to form a plurality of individual short-range transmission networks and also a mid-range, line of sight transmission network.

Abstract: A system includes a seismic acquisition system that includes a plurality of nodes and further includes an unmanned airborne vehicle. The unmanned airborne vehicle is to be used with the seismic acquisition system to conduct a seismic survey.

Abstract: The transmission method utilizes multiple seismic acquisition units within an array as intermediate short range radio receivers/transmitters to pass collected seismic data in relay fashion back to a control station. Any one seismic unit in the array is capable of transmitting radio signals to several other seismic units positioned within radio range of the transmitting unit, thus allowing the system to select an optimal transmission path. Utilizing an array of seismic units permits transmission routes back to a control station to be varied as needed. In transmissions from the most remote seismic unit to the control station, each unit within a string receives seismic data from other units and transmits the received seismic data along with the receiving unit's locally stored seismic data. Preferably, as a transmission is passed along a chain, it is bounced between seismic units so as to be relayed by each unit in the array.

Abstract: A seismic survey is conducted by positioning an array of remote acquisition units (RAUs). Each of the RAUs records seismic data derived torn one or more geophones in digital form in local memory. The data is collected by a harvester unit traversed across the survey territory as by an aircraft using point-multipoint communications, and subsequently transferred from the harvester unit to a central control unit.

Abstract: The transmission system combines a self-contained, wireless seismic acquisition unit and a wireless, line-of-site, communications unit to form a plurality of individual short-range transmission networks and also a mid-range line-of-site transmission network. Each seismic unit has a power source, a short-range transceiver and a geophone disposed within a casing. Each wireless communications unit is formed of an elongated support structure on which is mounted an independent power source, mid-range radio transceiver and a short-range transceiver configured to wirelessly communicate with the short-range transceiver of the acquisition unit. Preferably, the acquisition unit is buried under the ground surface, while the wireless communications unit is positioned adjacent in the near vicinity of the buried unit and vertically protrudes above the ground.

Abstract: A system and methods for acquiring seismic data is provided. In one aspect, the system and methods utilize a plurality of field service units placed over a region of interest, a repeater unit that wirelessly communicates with the field service units and a remote unit for controlling and processing the seismic data acquired by the field service units. In one aspect, the system and methods determine a condition associated with each of a plurality of attributes relating to acquisition of the seismic data at each field service unit, generate messages at each field service unit when the condition of a particular attribute meets a selected criterion, transmit the generated messages, receive the messages transmitted by at least a group of field service units at a repeater unit placed in the region of interest, analyze the messages received from the group of field service units at the repeater unit and then transmit information relating to the received messages to the remote unit for further processing.

Abstract: A seismic sensor unit includes a sensor housing including an inner chamber and a receiver extension for ground coupling, a suspension fluid disposed in the inner chamber, and a hydrophone suspended in the suspension fluid. The seismic sensor unit may include a sensor housing including a steel spike coupled to the ground, a fluid chamber in the sensor housing, a fluid in the fluid chamber, and a hydrophone disposed in the fluid chamber and contacting the fluid such as to detect a pressure wavefield in the fluid caused by ground motion acting on the steel spike. A method includes receiving ground motion at a seismic sensor unit coupled to the ground, transmitting the ground motion to a fluid chamber, creating a pressure wavefield in a fluid in the fluid chamber in response to the ground motion, and detecting the pressure wavefield in the fluid using a hydrophone.

Abstract: A data collection system that is operable to read out seismic data collected at wireless acquisition modules in response to source events such that the progression of subsequent source events occurs prior to the complete data record for a prior source event being collected at a data collection unit. The system may include mechanisms by which the source event progression is only interrupted based on a detected potential for loss of data integrity.

Abstract: A seismic survey is conducted by positioning an array of remote acquisition units (RAUs) (10). Each of the RAUs (10) records seismic data derived from one or more geophones in digital form in local memory. The data is collected by a harvester unit traversed across the survey territory as by an aircraft (24) using point-multipoint communications, and subsequently transferred from the harvester unit to a central control unit (26).

Abstract: A seismic survey is conducted by positioning an array of remote acquisition units (RAUs). Each of the RAUs records seismic data derived from one or more geophones in digital form in local memory. The data is collected by a harvester unit traversed across the survey territory as by an aircraft using point-multipoint communications, and subsequently transferred from the harvester unit to a central control unit.

Abstract: The invention relates to a device, a method and an apparatus for acquiring data, the device comprising a wireless network including a set of nodes (100), each node (100) including a sender (140) and a receiver (150) for sending and/or receiving and/or relaying data and/or commands, and a satellite positioning system (130), characterized in that each satellite positioning system (130) includes means for providing specific data used for time-stamping the data relative to a common time reference, organizing an access to the wireless network in a perfectly controlled manner, and routing data and/or commands within the network.

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: A seismic survey is conducted by positioning an array of remote acquisition units (RAUs). Each of the RAUs records seismic data derived from one or more geophones in digital form in local memory. The data is collected by a harvester unit traversed across the survey territory as by an aircraft using point-multipoint communications, and subsequently transferred from the harvester unit to a central control unit.

Abstract: There is provided herein a method of passive seismic acquisition that utilizes real time or near real time computation to reduce the volume of data that must be moved from the field to the processing center. Much of the computation that is traditionally applied to passive source data can be done in a streaming fashion. The raw data that passes through a field system can be processed in manageable pieces, after which the original data can be discarded and the intermediate results accumulated and periodically saved. These saved intermediate results are at least two, more likely three, orders of magnitude smaller than the raw data they are derived from. Such a volume of data is trivial to store, transport or transmit, allowing passive seismic acquisition to be practically used for continuous near-real-time seismic surveillance.

Abstract: A seismic data acquisition apparatus having a recorder co-located with a sensor unit in a seismic spread and a communication device for direct communication with a central recorder. A memory located in the recorder and/or in the central controller holds location parameters associated with the sensor unit, and the parameters can be updated. Methods of seismic data acquisition including sensing seismic energy and recording the sensed energy at the sensor location. Delivering the recorded information to a central recorder by manually retrieving removable memory from each recorder, by wireless transmission of the information, or by removing the information from each recorder by inductive or cable connectors and a transfer device. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure.

Abstract: A seismic data acquisition system includes a controller, a plurality of sensor stations and a plurality of seismic sources. Each sensor station includes a sensor coupled to the earth for sensing seismic energy in the earth. The sensor provides a signal indicative of the sensed seismic energy and a recorder device co-located with the sensor unit that receives and stores the signals. A communication device is co-located with the sensor station and provides direct two-way wireless communication with the central controller. In one embodiment, in-field personnel determine elevation values, or Z values, for the sensor stations and seismic source by accessing a digital elevation model or a look-up table based on the digital elevation model. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure.

Abstract: The transmission method utilizes multiple seismic acquisition units within an array as intermediate short range radio receivers/transmitters to pass collected seismic data in relay fashion back to a control station. Any one seismic unit in the array is capable of transmitting radio signals to several other seismic units positioned within radio range of the transmitting unit, thus allowing the system to select an optimal transmission path. Utilizing an array of seismic units permits transmission routes back to a control station to be varied as needed. In transmissions from the most remote seismic unit to the control station, each unit within a string receives seismic data from other units and transmits the received seismic data along with the receiving unit's locally stored seismic data. Preferably, as a transmission is passed along a chain, it is bounced between seismic units so as to be relayed by each unit in the array.

Abstract: The transmission system combines a self-contained, wireless seismic acquistion unit and a wireless, line of site, communications unit to form a plurality of individual short-range transmission networks and also a mid-range, line of sight transmission network.

Abstract: The transmission method utilizes multiple seismic acquisition units within an array as intermediate short range radio receivers/transmitters to pass collected seismic data in relay fashion back to a control station. Any one seismic unit in the array is capable of transmitting radio signals to several other seismic units positioned within radio range of the transmitting unit, thus allowing the system to select an optimal transmission path. Utilizing an array of seismic units permits transmission routes back to a control station to be varied as needed. In transmissions from the most remote seismic unit to the control station, each unit within a string receives seismic data from other units and transmits the received seismic data along with the receiving unit's locally stored seismic data. Preferably, as a transmission is passed along a chain, it is bounced between seismic units so as to be relayed by each unit in the array.

Abstract: In various embodiments, seismic receivers may detect seismic energy and transmit digital signals representative of the seismic energy to an S-line interface module (SLIM) and/or a smart antenna module (SAM) for collection. A SLIM may be used to connect two or more seismic receivers together. A SAM may include a memory medium for storing digital signals from seismic receivers (e.g., received directly from the seismic receivers or received through a connection to a SLIM) and a wireless transmitter to transmit data stored on the memory medium. The SAM may further include a Global Positioning System (GPS) receiver for receiving and storing timestamps, clock data, and/or positional data relative to the seismic receivers. The timestamps, clock data, and/or positional data may be transmitted along with the digital signal data to an external source (e.g., a laptop) for analysis to detect characteristics of subterranean formations.

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 survey system for acquiring survey data representative of a subterranean structure includes a plurality of sensor modules. Each of at least some of the plurality of sensor modules includes a wireless transceiver to communicate wireless signals with another component in the survey system, and a plurality of parts. A first of the plurality of parts is detachably attached to a second of the plurality of parts, with the first part including a sensor, and the second part including a power source and a non-volatile storage.

Abstract: A seismic exploration method and unit comprised of continuous recording, self-contained wireless seismometer units or pods. The self-contained unit may include a tilt meter, a compass and a mechanically gimbaled clock platform. Upon retrieval, seismic data recorded by the unit can be extracted and the unit can be charged, tested, re-synchronized, and operation can be re-initiated without the need to open the unit's case. The unit may include an additional geophone to mechanically vibrate the unit to gauge the degree of coupling between the unit and the earth. The unit may correct seismic data for the effects of crystal aging arising from the clock. Deployment location of the unit may be determined tracking linear and angular acceleration from an initial position. The unit may utilize multiple geophones angularly oriented to one another in order to redundantly measure seismic activity in a particular plane.