A fiber optic cable positioned along a casing string in a wellbore may be calibrated by exciting a tube wave in the wellbore and detecting, by the fiber optic cable, a reflected tube wave. The reflected tube wave may correspond to a reflection of the tube wave off an obstacle within the wellbore. The obstacle may have a known location such that a reference point along the fiber optic cable may be associated with the known location of the obstacle for calibrating the fiber optic cable. Downhole applications utilizing data collected by the calibrated fiber optic cable, including location data, may weight the data collected based at least in part on an uncertainty value associated with a particular calibrated location along the length of the fiber optic cable.

A marine seismic streamer includes plural concentrators, plural segments interposed with the plural concentrators so that a concentrator of the plural concentrators is sandwiched between two segments of the plural segments, a first high-voltage rail HV1 that extends along the plural concentrators and the plural segments, and a second high-voltage rail HV2 that extends along the plural concentrators and the plural segments. In each given concentrator i of the plural concentrators, there is a first switch SW1 placed along one of the first high-voltage rail HV1 and the second high-voltage rail HV2, a second switch SW2 placed between the first high-voltage rail HV1 and the second high-voltage rail HV2, a first local controller implemented in hardware, and a second local controller implemented in a combination of hardware and software, and having an operating system, the first local controller being separated from the second local controller.

A marine seismic streamer includes plural concentrators, plural segments interposed with the plural concentrators so that a concentrator of the plural concentrators is sandwiched between two segments of the plural segments, a first high-voltage rail HV1 that extends along the plural concentrators and the plural segments, and a second high-voltage rail HV2 that extends along the plural concentrators and the plural segments. In each given concentrator i of the plural concentrators, there is a first switch SW1 placed along one of the first high-voltage rail HV1 and the second high-voltage rail HV2, a second switch SW2 placed between the first high-voltage rail HV1 and the second high-voltage rail HV2, a first local controller implemented in hardware, and a second local controller implemented in a combination of hardware and software, and having an operating system, the first local controller being separated from the second local controller.

In a display system, each of a plurality of sensor terminals estimates first information based on accumulated first measurement data and transmits the first information to a display device. The display device synchronizes a received plurality of kinds of the first information at time and classifies the plurality of kinds of first information into a plurality of first information groups, estimates, based on position information of the plurality of sensor terminals and the first information included in each of the first information groups, updates the first information group, generates, for each of the updated plurality of first information groups, based on map information including a region where a structure is located, image information including a distribution of values of the first information on a map, and displays an image based on the image information.

In a display system, each of a plurality of sensor terminals estimates first information based on accumulated first measurement data and transmits the first information to a display device. The display device synchronizes a received plurality of kinds of the first information at time and classifies the plurality of kinds of first information into a plurality of first information groups, estimates, based on position information of the plurality of sensor terminals and the first information included in each of the first information groups, updates the first information group, generates, for each of the updated plurality of first information groups, based on map information including a region where a structure is located, image information including a distribution of values of the first information on a map, and displays an image based on the image information.

An automatic microseismic monitoring-intelligent rockburst early warning integrated method is further provided.

Aspects of the present disclosure describe dynamic road traffic noise mapping using DFOS over a telecommunications network that enables mapping of road traffic-induced noise at any observer location. DFOS is used to obtain instant traffic data including vehicle speed, volume, and vehicle types, based on vibration and acoustic signal along the length of a sensing fiber along with location information. A sound pressure level at a point of interest is determined, and traffic data associated with such point is incorporated into a reference noise emission database and a wave propagation theory for total sound pressure level prediction and mapping. Real-time wind speed using DFOS—such as distributed acoustic sensing (DAS)—is obtained to provide sound pressure adjustment due to the wind speed.

An apparatus for detecting a location of an optical fiber having an acoustic sensor disposed subsurface to the earth includes an acoustic emitter configured to emit a first signal having a first frequency and a second signal having a second frequency that is higher than the first frequency, the first and second emitted acoustic signals being azimuthally rotated around the borehole and an optical interrogator configured to interrogate the optical fiber to receive an acoustic measurement that provides a corresponding first received signal and a corresponding second received signal. The apparatus also includes a processor configured to (i) frequency-multiply the first received signal to provide a third signal having a third frequency within a selected range of the second frequency, (ii) estimate a phase difference between the second received signal and the third signal, and (iii) correlate the phase difference to the location of the optical fiber.

Systems and methods for detecting a mechanical disturbance are disclosed. One of the method may comprise the operation steps including: transmitting, by a transmitter, a pulse at a preset frequency along a first cable; receiving, by a receiver, a plurality of signals, wherein each of the plurality of signals travels along the first cable and a second cable connected to the receiver for a corresponding span; calculating one or more differential phases, wherein each differential phase is calculated based on respective phases and the corresponding spans of two of the plurality of signals; and determining a localization of the mechanical disturbance based on the one or more differential phases.

A method for determining microseismic events. The method may include measuring a seismic travel time of a microseismic event with a fiber optic line disposed in a first wellbore, forming a probability density function for the microseismic event based at least in part on the seismic travel time measurement, modifying the probability density function by applying one or more constraints to form a modified probability density function, identifying one or more most probable source locations from the modified probability density function, and forming a microseismic event cloud from the one or more most probable source locations.