Abstract: Methods are provided for determining properties of an anisotropic formation (including both fast and slow formations) surrounding a borehole. A logging-while-drilling tool is provided that is moveable through the borehole. The logging-while drilling tool has at least one dipole acoustic source spaced from an array of receivers. During movement of the logging-while-drilling tool, the at least one dipole acoustic source is operated to excite a time-varying pressure field in the anisotropic formation surrounding the borehole. The array of receivers is used to measure waveforms arising from the time-varying pressure field in the anisotropic formation surrounding the borehole. The waveforms are processed to determine a parameter value that represents shear directionality of the anisotropic formation surrounding the borehole.

Abstract: An obstacle detection device includes a traveling direction determination unit configured to determine a traveling direction of an own vehicle based on acquired steering angle information and shift position information, and an obstacle determination unit configured to set a detection range as a predetermined range around the own vehicle, determines, when an object detected based on sensor data is positioned inside the detection range, the object as an obstacle that obstructs traveling of the own vehicle, and outputs a control signal for stopping the traveling of the own vehicle or decelerating the own vehicle. The obstacle determination unit changes the detection range based on a determination result of the traveling direction determination unit.

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

Abstract: Downhole tools and method for a well. At least some of the example embodiments are methods of imaging a formation around a first borehole, including: focusing first outbound acoustic energy, launched from a tool with the first borehole, on a volume within the formation spaced away from the first borehole, the focusing creates a first virtual point source (VPS) that creates a first return acoustic energy; receiving the first return acoustic energy from the first VPS at a plurality of seismic sensors; and determining a parameter of the formation between the first VPS and a location of the seismic sensors using the first return acoustic energy.

Abstract: A light detection and ranging system includes synchronously scanning transmit and receive mirrors that scan a pulsed fanned laser beam in two dimensions. Imaging optics image a receive aperture onto an arrayed receiver that includes a plurality of light sensitive devices. Adaptive methods dynamically modify the size and location of the field of view as well as laser pulse properties in response to internal and external sensors data.

Abstract: An ultrasonic data transmission method, apparatus and system, a terminal device and a medium are provided. The method is applied to a transmitting terminal which includes at least two ultrasonic signal transmitting arrays. The method includes: a single-frequency ultrasonic coding signal of to-be-transmitted information corresponding to each ultrasonic signal transmitting array is respectively determined, ultrasonic codes of to-be-transmitted information corresponding to different ultrasonic signal transmitting arrays being different; and corresponding at least two single-frequency ultrasonic code signals are transmitted through the at least two ultrasonic signal transmitting arrays to a receiving terminal in a focusing mode, frequency bands of transmitting frequencies of different ultrasonic signal transmitting arrays being different.

Abstract: An ultrasonic transducer device comprises a piezoelectric micromachined ultrasonic transducer (PMUT), a transmitter with first and second differential outputs, and a controller. The PMUT includes a membrane layer. A bottom electrode layer, comprising a first bottom electrode and a second bottom electrode, is disposed above the membrane layer. The piezoelectric layer is disposed above the bottom electrode layer. The top electrode layer is disposed above the piezoelectric layer and comprises a segmented center electrode disposed above a center of the membrane layer and a segmented outer electrode spaced apart from the segmented center electrode. The controller, responsive to the PMUT being placed in a transmit mode, is configured to couple the first and second segments of the bottom electrode layer with ground, couple the first output of the transmitter with the segments of the segmented center electrode, and couple the second output with the segments of the segmented outer electrode.

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: A scanning LiDAR system includes a base frame, an optoelectronic assembly, and a lens assembly. The optoelectronic assembly includes one or more laser sources and one or more photodetectors, and is fixedly attached to the base frame. The lens assembly includes one or more lenses. The one or more lenses have a focal plane. The scanning LiDAR system further includes a first flexure assembly flexibly coupling the lens assembly to the base frame. The first flexure assembly is configured such that the one or more laser sources and the one or more photodetectors are positioned substantially at the focal plane of the one or more lenses. The first flexure assembly is further configured to be flexed so as to scan the lens assembly laterally in a plane substantially perpendicular to an optical axis of the emission lens.

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 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 lidar system comprises (1) an array of pixels for sensing incident light and (2) a circuit for processing a signal representative of the sensed incident light to detect a reflection of a laser pulse from a target within a field of view. The circuit can comprise a plurality of matched filters that are tuned to different reflected pulse shapes for detecting pulse reflections within the incident light, and wherein the circuit (1) applies the signal to the matched filters to determine an obliquity for the target based how the matched filters respond to the applied signal and (2) determines a correction angle based on the determined target obliquity, the correction angle for orienting the field of view to a frame of reference in response to a tilting of the lidar system. In an example embodiment, the circuit can comprise a signal processing circuit that performs the signal application and correction angle determination operations.

Abstract: System and method for generating Pulse Position Modulated (PPM) lidar waveforms generating Pulse Position Modulated (PPM) waveforms in a lidar includes: a) creating a modulation pool, based on a maximum nominal pulse repetition frequency (PRF); b) eliminating bad modulation levels from the modulation pool to generate a good modulation pool; c) selecting a modulation level from the good modulation pool to generate a PPM code element; d) repeating steps b and c N times to generate an N-element PPM code, wherein the PPM code is PRF independent; e) selecting a PRF less than the maximum nominal PRF; f) generating a PPM waveform by applying the N-element PPM code to the selected PRF; and g) transmitting the PPM waveform by the lidar toward a target to determine a range to the target.

Abstract: Methods and devices for correcting underwater photon displacement and for depth sounding with a single-photon Lidar are provided. The method includes: acquiring a pointing angle of a photon emitted by the single-photon Lidar, and coordinates of a water-surface photon signal and a water-bottom photon signal returned by the photon emitted by the single-photon Lidar; performing a sea wave fitting according to the water-surface photon signal to determine a sea wave model; determining an intersection of the photon and an air-water interface according to coordinates of any water-bottom photon, the pointing angle and the sea wave model; determining an underwater displacement error of the photon according to the intersection, the sea wave model and the pointing angle; and correcting the coordinates of the water-bottom photon according to the underwater displacement error. The invention performs sea wave modeling through water surface photon signal and determines intersection of the photon and water-air interface.

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: A method for calibrating a vehicle sensor of a motor vehicle. The method includes: ascertaining sensor data for a plurality of measuring points in time during a total measuring time period, the total measuring time period being subdivided into partial measuring time periods, and the motor vehicle moving relative to objects in surroundings of the motor vehicle; for each partial measuring time period, computing positions of the objects based on the ascertained sensor data; for each partial measuring time period, computing a partial measuring time period sinogram based on the computed positions; computing a total measuring time period sinogram by adding the partial measuring time period sinograms and correcting using a factor that is a function of the partial measuring time period sinograms; ascertaining an orientation of the vehicle sensor based on the total measuring time period sinogram; and calibrating the vehicle sensor based on the ascertained orientation.

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: Aspects of the present disclosure involve systems, methods, and devices for mitigating Lidar cross-talk. Consistent with some embodiments, a method includes detecting a noise signal producing noise in one or more return signals being received by a Lidar unit of an autonomous vehicle (AV) system, and detecting a noise source corresponding to the noise signal. The detecting of the noise source comprises determining a direction of the noise source relative to the AV system and determining a classification of the noise source based on an intensity of the noise signal. The method further includes generating state data to describe the noise source based on the direction of the noise source relative to AV system and the classification of the noise source. The method further includes controlling one or more operations of the AV system based on the state data describing the noise source.

Abstract: A sonar system for a watercraft, including a shaft defining a top and a bottom end. The system includes a first attachment operatively connected to the top end of the shaft, and a second attachment operatively connected to the bottom end of the shaft including a transducer assembly. The first attachment defines a first member pivotably connected to the top end of the shaft, and a handle member rotatably attached about the first member. The second attachment defines a second member pivotably connected to the bottom end of the shaft, and a bracket member rotatably attached about the second member. The system comprises a first connector extending between the first and second members and configured to cause reciprocal movement between the first and second members. The system comprises a second connector extending between the first and second members and configured to cause reciprocal rotation between the first and second members.