Abstract: A method and system for determining cement bonding, or other materials attached to a pipe string. A well measurement system for determining cement bonding or other materials attached to a pipe string may comprise an acoustic logging tool, wherein the acoustic logging tool comprises at least one receiver and at least one transmitter. The well measurement system may further comprise an information handling system, wherein the information handling system is configured to broadcast a signal with the transmitter, record the reflected signal with a receiver; and determine an integrity of a cement using a Quintero Wellbore Index.

Abstract: Described are micromachined ultrasonic transducers (MUTs) with convex or concave electrodes, which have enhanced pressure amplitude and frequency response behavior when driven at fundamental and harmonic frequencies, as well as methods of making the same.

Abstract: A 1D ultrasonic transducer unit for area monitoring, having a housing having a securing device for securing to a surface and having at least three discrete ultrasonic transducers designed to decouple sound waves with a consistent operating frequency between 20 kHz and 400 kHz in a gaseous medium, and a control unit designed to control each ultrasonic transducer individually, wherein two ultrasonic transducers, directly adjacent to one another, are spaced apart by a distance, the 1D ultrasonic transducer unit has a sound channel per ultrasonic transducer with an input opening, associated with exactly one respective ultrasonic transducer, and an output opening, the output openings are arranged along a straight line, a distance from the directly adjacent output opening corresponds at most to the full or half the wavelength in the gaseous medium and is smaller than the corresponding distance.

Abstract: A method for reconstructing a signal from a subset of the full signal is disclosed. In one embodiment, the method includes receiving a plurality of randomly sampled multichannel radio-frequency or in-phase and quadrature signals acquired from a physical environment including a transmitter, a propagation medium and a receiver; modelling the full signal as a matrix comprising a plurality of vector signals wherein the full signal is expressed as a matrix product of a first matrix and a second matrix; updating the second matrix based on an objective function to produce an updated second matrix; determining a convergence parameter in dependence upon the evaluated objective function; and modifying the updated second matrix in dependence upon the convergence parameter.

Abstract: A method of tracking a known object is presented, wherein a sonar image of an object which is distorted by an artifact associated with sonar imaging is compared with an image generated from a model of the object, and at least one of the two images is modified to reduce differences between them.

Abstract: A method for ultrafast compound plane wave imaging based on a broadband acoustic metamaterial: controlling the transmit-receive ultrasonic probe to emit an ultrasonic signal at a preset transmit frequency and a first preset transmit angle, the preset transmit frequency is equal to a response frequency of the acoustic metamaterial structure; controlling the transmit-receive ultrasonic probe to receive, at a preset receive frequency and separately at a first preset receive angle, a second preset receive angle, a third preset receive angle, echo signals reflected by a measured object, where the preset receive frequency is n times the preset transmit frequency, the first preset receive angle is equal to the first preset transmit angle, the second preset receive angle is smaller than the first preset transmit angle, the third preset receive angle is larger than the first preset transmit angle; using the echo signals to reconstruct an image of the measured object.

Abstract: A method is disclosed comprising: transmitting a pair of tracking signals, the pair of tracking signals including a first tracking signal and a second tracking signal; receiving a data set that is collected by using a sensor in a sensor array, the data set including: (i) a received first tracking signal that is generated by the sensor in response to receiving the first tracking signal, (ii) a received second tracking signal that is generated by the sensor in response to receiving the second tracking signal, and (iii) a received target signal; detecting a relative delay at which the first tracking signal and the second tracking signal are received by the sensor; removing the received first tracking signal and the received second tracking signal from the data set to produce a filtered data set; and providing the filtered data set and an indication of the relative delay to a beamformer.

Abstract: A micromachined ultrasonic transducer (MUT) which comprises a first piezoelectric layer and a second piezoelectric layer. The first piezoelectric layer is disposed between a first electrode and a second electrode. The second piezoelectric layer is disposed between the second electrode and a third electrode. At least the first electrode has first and second ends along a first axis, one or more of which is defined by a radius of curvature R. A second axis normal to the first passes through a midpoint of the first axis. A half-width of the first electrode is defined by a length L measured from the midpoint, in the direction of the second axis, to an outer perimeter of the first electrode. A total width of the first electrode at its narrowest point along the first axis is at most 2L such that the first electrode has a concave shape. R/L, is greater than 1.

Abstract: A 1D ultrasonic transducer unit for detecting danger for a vehicle, comprising a housing mounted on the vehicle, which includes at least three discrete ultrasonic transducers, designed to decouple sound waves at a corresponding working frequency between 20 kHz and 400 kHz into a gaseous medium, and a control unit, designed to control each ultrasonic transducer individually, two ultrasonic transducers directly adjacent to each other in each case having a distance, the 1D ultrasonic transducer unit having one sound channel per ultrasonic transducer, each with one inlet opening assigned to exactly one ultrasonic transducer and one outlet opening (26), the outlet openings being arranged along a straight line, a distance from directly adjacent outlet openings corresponding to no more than the full or half wavelength in the gaseous medium and being shorter than the corresponding distance.

Abstract: An acoustic detection system for detecting at least partly submerged targets in a sensitive area defined with respect to an infrastructure, wherein the system includes at least one multistatic detection group, each multistatic detection group defining a detection area, and comprising: a submerged transmitter transmitting at low frequencies; a plurality of submerged receivers comprising at least two receivers, each receiver of a given group forming, with the transmitter of the group, a bistatic pair, each bistatic pair generating an elementary detection area surrounding a blind zone, the detection area of the group being formed by all of the elementary detection areas of the receivers of the group, the blind zone of each receiver in a given detection group being at least partly covered by the elementary detection areas of the neighbouring receivers of the detection system.

Abstract: In an ultrasonic detection system that uses frequency-modulation or phase-modulation coding to distinguish emitted bursts from multiple transducers, a receiver associated with a transducer uses peak search, peak buffer, and peak rank stages in one or more receiver signal processing paths to identify valid received ultrasonic signal envelope peaks in correlator outputs. The peak rank stage can support different modes respectively designed to handle one code, two or more codes, or two or more codes with support for Doppler frequency shift detection. Valid peak information (e.g., amplitude and time) can be reported to a central controller and/or stored locally in a fusion stage to generate more intelligent information for targets or obstacles using peaks from multiple bursts.

Abstract: A method of collision localization on a robotic device includes obtaining audio signals from a plurality of acoustic sensors spaced apart along the robotic device; identifying, based on a collision being detected, a strongest audio signal; identifying a primary onset time for an acoustic sensor producing the strongest audio signal, the primary onset time being a time at which waves propagating from the collision reach the acoustic sensor producing the strongest audio signal; generating a virtual onset time set, by shifting a calibration manifold, based on the identified primary onset time, the calibration manifold representing relative onset times from evenly spaced marker locations on the robotic device to the plurality of acoustic sensors; determining scores for the marker locations based a standard deviation of elements in the virtual onset time set; and estimating a location of the collision based on a highest score of the determined scores.

Abstract: An object detector includes: a triangulation calculation unit that performs triangulation calculation for detecting a location of an object based on first distance information calculated based on direct waves in which transmitted waves transmitted from a first transmission and reception unit are reflected by an object and received by the first transmission and reception unit, and second distance information calculated based on indirect waves in which transmitted waves transmitted from a second transmission and reception unit arranged in a location different from the first transmission and reception unit are reflected by an object and received by the first transmission and reception unit; and a prohibition processing unit that prohibits triangulation calculation when a difference between first velocity information indicating a velocity of an object calculated based on the direct waves and second velocity information indicating a velocity of an object calculated based on the indirect waves exceeds a predetermin

Abstract: An ultrasonic target, including a main reflector, the main reflector including three main faces, extending from a main vertex, the main faces forming a main trirectangular trihedron; defining a main base plane, lying facing the main vertex, and forming a base of the main trirectangular trihedron; the target including at least one auxiliary reflector fastened to the main reflector, the or each auxiliary reflector including three auxiliary faces, extending from an auxiliary vertex, the auxiliary faces forming an auxiliary trirectangular trihedron; defining an auxiliary base plane, lying facing the auxiliary vertex, and forming a base of the auxiliary trirectangular trihedron.

Abstract: Aspects of the present disclosure describe distributed fiber optic sensing systems, methods, and structures that advantageously are employed to determine the location and depth of underground fiber-optic facilities that may be carrying telecommunications traffic.

Abstract: A seismic source having two or more operating heads with a firing chamber pressure vessel of compressed air for generating seismic oscillations at low and ultra-low frequencies (ULF) for marine seismic exploration. The multi-headed sound source increases low frequency signal in ranges from below 1 Hz to around 7 Hz to provide greater penetration of the seismic signal through complex overburden such as salt or basalt, improve velocity model building with methods such as Full Wave Inversion, improve the ability to build blocky reservoir models, and improve resolution by reducing side lobes.

Abstract: A method of operating electro-acoustical transducers such as PMUTs involves applying to the transducer an excitation signal over an excitation interval, acquiring at the transducer a ring-down signal indicative of the ring-down behavior of the transducer after the end of the excitation interval, and calculating, as a function of said ring-down signal, a resonance frequency of the electro-acoustical transducer. A bias voltage of the electro-acoustical transducer can be controlled as a function of the resonance frequency. An acoustical signal received can be transduced into an electrical reception signal and a damping parameter of the electro-acoustical transducer can be calculated as a function of the ring-down signal so that a cross-correlation reference signal can be synthesized as a function of the resonance frequency and the damping ratio of the electro-acoustical transducer.

Abstract: A device and method used to increase the resolution when imaging, measuring and inspecting wells, pipes and objects located therein. The device comprises an array of acoustic transducers that both transmit and receive acoustic signals. Scan lines may be overlapped by interlacing transmission and receiving windows thus increasing either the resolution or logging speed drastically compared to conventional approaches. The sequence of the scan lines making up an imaging frame is created by stratifying physically close lines and randomly selecting from within each stratum, preventing interference from neighboring transducers, signals and acoustic artifacts that fundamentally limit logging speed and resolution using conventional methods.

Abstract: A transducer system comprises a first frequency steered transducer array element and a second frequency steered transducer array element that is spaced apart from the first frequency steered transducer array element. The system additionally includes a processing element in communication with the first and second frequency steered transducer array elements. The processing element is configured to receive a first receive electronic signal from the first frequency steered sonar array element, receive a second receive electronic signal from the second frequency steered array sonar element, compare a difference in amplitude between the first receive electronic signal and the second receive electronic signal to determine a cross-track position of an underwater target, and control a display to present an indication of the cross-track position of the underwater target.

Abstract: Embodiments include devices, system and processes for facilitating ultra-short range detection of obstacles using a PAS sensor. A process may include obtaining a correlation of at least two characteristics of a transducer; determining a given transmission frequency and selecting a reverberation time desired for the transducer; obtaining a damping ratio corresponding to the selected reverberation time; generating a ranging signal command; generating a damping signal command; and outputting each of the ranging signal command and the damping signal command. The ranging signal command may instruct a PAS sensor to drive the transducer to output a ranging signal at the given transmission frequency, at a transmission amplitude, and at a transmission phase and the damping signal command results in a dampening, at the damping ratio, of transducer reverberations arising from the ranging signal. The damping ratio may be between thirty percent (30%) and eighty percent (80%) of the transmission amplitude.