Abstract: Some aspects relate to techniques for calibrating a logging tool. In some implementations, the logging tool may estimate certain unknown properties of a signal based on distances between transmitters and receivers of the logging tool and based on frequencies used by the transmitters and receivers. The logging tool may estimate the unknown properties by interpolating values into a mathematical function related to the above-noted distances and frequencies. After estimating the unknown properties, the logging tool may be deployed into the wellbore, where it may use the estimated properties to process signals received through a subsurface formation.

Abstract: A fish finder system is provided with a capture device information input terminal configured to input a capture device information, a capture device dropping point input terminal configured to input a dropping point at which a capture device is dropped, a tidal current input terminal configured to input tidal current information including a tidal current direction and a tidal current speed, and processing circuitry communicatively coupled to the capture device information input terminal, the capture device dropping point input terminal, and the tidal current input terminal. The processing circuitry is configured to calculate a drift amount of the capture device relative to the dropping point and calculate a capture device arrival point at which the capture device arrives in the water.

Abstract: Target value detection for an unmanned aerial vehicle is described. The unmanned aerial vehicle includes a first transducer that transmits a first ultrasonic signal and receives a first ultrasonic response and a second transducer that transmits a second ultrasonic signal and receives a second ultrasonic response. The second transducer has a wider beam pattern than the first transducer. Determinations are made as to whether either or both of the first or second ultrasonic responses includes a target value within range areas associated with the respective beam patterns of the first and second transducers. A confidence value is generated based on the determinations. The target value is reflected from an object and the confidence value indicates a likelihood of a position of the unmanned aerial vehicle with respect to the object.

Abstract: An ultrasound imaging system has an array of ultrasound transducers comprising a set of sub-arrays of transducers. Each transducer (100) has an analogue buffer (106). Each sub-array of transducers has a signal path (102, 104) from within the array of ultrasound transducers to outside the array of ultrasound transducers which comprises one or more hops between the buffers (106). To reduce the signal line length from inside the array of ultrasound transducers to the periphery, at least some multiple hops between buffers (106) are provided. Each buffer hop introduces a delay, but prevents signal degradation so that a large number of analog signals can be transmitted across the large area ASIC of the transducer array.

Abstract: Provided is a piezoelectric film capable of realizing an electroacoustic conversion film or the like in which the durability is high and a sufficient sound pressure with respect to an input operating voltage is obtained. The piezoelectric film is a piezoelectric film including a polymer-based piezoelectric composite material which contains piezoelectric particles in a matrix containing a polymer material, and electrode layers which are provided on both surfaces of the polymer-based piezoelectric composite material, in which in a case where a cross section of the piezoelectric film in a thickness direction is observed with a scanning electron microscope, the polymer-based piezoelectric composite material is divided into two equal regions in the thickness direction, and void volumes of the two regions are measured, a ratio of the void volume obtained by dividing the void volume of the region with a larger void volume by the void volume of the region with a smaller void volume is 1.2 or greater.

Abstract: The thickness of borehole casing can be determined by ultrasound logging in conjunction with simulations of ultrasonic plane-wave echo waveforms across a range of frequencies for a plurality of casing thicknesses and correlation of synthetic frequency spectra derived from the simulated plane-wave echo waveforms for the various casing thicknesses against the frequency spectrum of a measured pulse-echo waveform. In accordance with various embodiments, a portion of the measured pulse-echo waveform that corresponds to the first reflection off the interface between the borehole casing and the borehole fluid is used as a driving pulse to weight the simulated plane-wave echo waveforms in the synthetic frequency spectrum.

Abstract: Encoded transmit signals are provided to an ultrasound array such diverging ultrasound waves are sequentially transmitted. Each diverging ultrasound wave is generated by a respective set of encoded transmit signals, where each set of encoded transmit signals is encoded by a respective row of an N×N invertible orthogonal matrix. Only a selected subset of M rows, with N<M, is employed to encode the transmit signals. Sets of receive signals detected in response to the transmitted diverging ultrasound waves are decoded via a transposed matrix generated based on the invertible orthogonal matrix, with each set of decoded receive signals being associated with insonification via a subset of the ultrasound array elements in the fixed aperture. Synthetic aperture beamforming is performed on the decoded receive signals to generate an ultrasound image.

Abstract: In one form, an acoustic distance measuring circuit includes a frequency generator, a transmitter amplifier, an acoustic transducer, and a sensing circuit. The sensing circuit includes an input adapted to be coupled to the acoustic transducer, for receiving an input signal. The sensing circuit provides an in-phase portion and a quadrature portion of the input signal to a filter. The sensing circuit filters the in-phase portion and the quadrature portion and calculates a phase of the input signal in response to the filtered in-phase and quadrature portions. The sensing circuit determines a frequency slope of the input signal in response to calculating the phase and provides the frequency slope of the input signal to an output.

Abstract: A small aperture acoustic velocity sensor and a method for velocity measurement are disclosed. In one aspect, the disclosed technology uses spatially-shifted sub-arrays for projection and/or hydrophone receipt and cross-correlation of successive pulses to improve correlation and reduce bias. The spatial shift can be created physically by selection of groups of elements or virtually by weighting the contributions of fixed sub-arrays. Spatial modulation can be used to form a projected signal and measured spatial phase of slope across the set of sub-arrays allows correction of both long- and short-term errors. The disclosed technology uses spatial and/or temporal interpolation.

Abstract: The present invention a sparse optimization method based on cross-shaped three-dimensional imaging sonar array, comprising the following steps: first, constructing a beam pattern simultaneously applicable to a near field and a far field based on a cross-shaped array; then, constructing an energy function required by sparse optimization according to the beam pattern; then, introducing an array element position disturbance into a simulated annealing algorithm to increase the degree of freedom of the sparse process and increase the sparse rate of the sparse array, and using the simulated annealing algorithm to sparse optimization of the energy function; finally, after optimization, a sparse optimization cross-shaped array is obtained. The present invention ensures that the three-dimensional imaging sonar system has the desired performance at any distance, and greatly reduces the hardware complexity of the system.

Abstract: The present disclosure is directed to systems and methods to perform or facilitate operation of a seismic survey. The system can include a seismic data acquisition unit. The seismic data acquisition unit can include a cap free subsea connector. The connector can be formed of a snap ring, pin interconnect and socket insert. The snap ring can contact the pin interconnect. The pin interconnect can contact the socket insert. The socket insert can be in contact with isolation electronics within the seismic data acquisition unit. The snap ring can lock or keep the pin interconnect in contact with the socket insert. The pin interconnect can be removable and replaceable.

Abstract: An electronic device and methods for providing high resolution ranging measurements are disclosed. The electronic device includes a pulse generator, a memory, an ADC, a timer, a comparator, a processing unit, connectors for coupling to a transceiver and instructions stored in the memory. The instructions, when performed by the processing unit, performs a method that determines an estimated time of arrival of a series of measurement pulses in the signal and turns on, prior to the estimated time of arrival, the ADC to capture the series of measurement pulses using a first resolution provided by sampling the signal at a rate equal to or greater than the Nyquist rate. The ADC remains on for a fixed time period sized to capture the series of measurement pulses.

Abstract: Embodiments of the present disclosure provide apparatus, methods and computer programs for ultrasonic proximity-detection.

Abstract: Methods, systems, devices, and products for hydrocarbon tubular evaluation. Methods comprise conveying the logging tool in the tubular with a carrier; inducing with a transmitter a horizontal shear (SH) wave; identifying higher order SH mode signals received at a plurality of offset receivers responsive to a higher order SH mode engendered by the horizontal shear (SH) wave; estimating a dominant frequency for higher order SH mode from the higher order SH mode signals; estimating a group velocity for the higher order SH mode from the higher order SH mode signals; and estimating a tubular parameter using the dominant frequency and the group velocity. The tubular parameter may be at least tubular thickness. The method includes estimating the tubular parameter independent of the fundamental horizontal shear wave mode (SH0).

Abstract: An acoustic imaging metamaterial is provided for obtaining edge detection information of a tangible object. The acoustic imaging metamaterial includes a longitudinally extending phononic crystal substrate that defines a first major surface and a second major surface opposite the first major surface. A first structurally rigid grating layer is disposed adjacent the first major surface, and a second structurally rigid grating layer is disposed adjacent the second major surface. In various aspects, the first and second structurally rigid grating layers are identical in shape and dimensions, and are aligned with one another. The acoustic imaging metamaterial is configured to redirect, confine, and/or manipulate an incident acoustic wave resulting in a high contrast image used for extracting edge detection information of the tangible object. The background medium fluid of the system can be air or a fluid such as water.

Abstract: An object detection device includes: a wave receiver that receives a reflected wave generated by reflection, by an object, of a transmission wave incident on the object; a determination section that determines whether, in a change over time in an amplitude of the reflected wave received by the wave receiver, an amplitude of a falling portion is greater than a predetermined criterion, the amplitude of the falling portion being decreased after the amplitude has reached a maximum value; and a processing section that, on the basis of a determination by the determination section that the amplitude of the falling portion is greater than the predetermined criterion, performs a process in which the object is treated as an object to be avoided.

Abstract: Systems and methods provide for the reduction of motion at a ground layer of a site due to a seismic event. A predicted seismic motion is obtained for a geological layer at depth and properties of the layers between the ground layer and layer at depth are determined. A model is created using the layers and the predicted seismic motion. Iteratively for each layer, one or more properties of the layer is changed in the model and a site amplification is performed to determine a change or changes that result in an acceptable response at the ground layer. Subsequently, the in situ layer may be modified according to the modified property or properties to reduce motion at the site due to a seismic event.

Abstract: A method for positioning an underwater glider based on a virtual TDOA of a single beacon is provided. In the method, a positioning beacon periodically sends positioning messages, where the positioning message includes longitude, latitude and depth information of the positioning beacon; the underwater glider receives the positioning messages and records TOAs at which the positioning messages arrive at an acoustic positioning signal receiving module; and the underwater glider parses the positioning messages and stores positioning message data, creates virtual beacons based on beacon information and attitude information of the underwater glider, corrects the TOAs, and calculates a position of the underwater glider according to a TDOA algorithm. According to the method, the underwater glider passively listens to and receives the positioning messages without sending a positioning request to the positioning beacon, making the entire positioning process energy-saving with a certain degree of concealment.

Abstract: A beamforming device includes a sampler configured to sample a signal reflected from a focal point and received to a transducer array; a mixer configured to separate the sampled signal into an in-phase component signal and a quadrature component signal; a low pass filter configured to perform filtering on the in-phase component signal and the quadrature component signal; a decimator configured to perform decimation on the filtered in-phase component signal and quadrature component signal; a sampling delay compensator configured to compensate a sampling time delay based on a preset time delay resolution for the decimated in-phase component signal and quadrature component signal; a phase rotator configured to compensate a phase delay based on a preset phase resolution for the in-phase component signal and the quadrature component signal for which the sampling time delay is compensated; and a delay calculator configured to calculate a time delay resolution and the phase resolution, and to apply each to the sampl

Abstract: A method of detecting an event by: obtaining a first sample data set; determining a frequency domain feature(s) of the first sample data set over a first time period; determining a first threshold for the a frequency domain feature(s) using the first sample data set; determining that the frequency domain feature(s) matches the first threshold; determining the presence of an event during the first time period based on determining that the frequency domain feature(s) matches the first threshold; obtaining a second sample data set; determining a frequency domain feature(s) of the second sample data set over a second time period; determining a second threshold for the frequency domain feature(s) using the second sample data set; determining that the frequency domain feature(s) matches the second threshold; and determining the presence of the event during the second time period based on determining that the frequency domain feature(s) matches the second threshold.