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.

Abstract: The present invention relates to an underwater communication method capable of communicating with a plurality of sensor nodes within a limited frequency band. Underwater information communication of the present invention allocates an appropriate frequency to each sensor node according to the distance between a central node and the plurality of sensor nodes, and then, controls underwater communication between the central node and the plurality of sensor nodes using the allocated frequency. By virtue of such control, the present invention prevents the occurrence of an unusable sensor node which cannot smoothly perform underwater communication when the allocated frequency is unreasonable. Therefore, the present invention has the effect of enabling efficient underwater communication between a plurality of sensor nodes and a central node.

Abstract: In a sonar system using a large array multielement sonar detector to detect reflected signals sent out by a sonar ping generator, the sent out sonar ping generator sends out varying frequency sonar signals during each ping, where the frequency is neither monotonically increasing or monotonically decreasing.

Abstract: A communication unit for an electrical machine, in particular a hand-held machine tool, includes at least one electrical actuator, a control unit configured to control the at least one electrical actuator, and a receiving unit assigned to a mobile or stationary unit. The at least one electrical actuator and the control unit together form a transmission unit. The transmission unit is configured to transmit data, and the receiving unit is configured to receive the data. The receiving unit includes at least one microphone. To transmit data, via the transmission unit, the control unit is configured to trigger the electrical actuator to generate an acoustic signal that is detectable by the at least one microphone.

Abstract: An underwater acoustic communication system for a mobile electronic device, such as a smartphone, has a communication unit with one or more ultrasonic transducers to transmit and receive underwater ultrasonic signals. The communication unit is connected to an audio auxiliary interface of the mobile electronic device. A processing unit in communication with the auxiliary interface receives RF signals from and transmits RF signals to the communication unit via the audio auxiliary interface.

Abstract: The invention relates to a matrix array of ultrasonic transducer elements comprising a plurality of transducer elements that are distributed over a distribution area, each of the transducer elements being suitable for emitting, from an emission surface, ultrasound at a frequency comprised between 100 kHz and 100 MHz, wherein: each of the transducer elements is configured to emit ultrasound divergently at least level with the working volume; the largest dimension of the emission area of each of said transducer elements is larger than 1.5 times the wavelength of the ultrasound in water at 30° C.; and the distribution of the transducer elements over the distribution area of the array is aperiodic.

Abstract: Disclosed herein are ultrasonic transducer systems comprising: an ultrasonic imager comprising a plurality of pMUT transducer elements; and one or more circuitries connected electronically to the plurality of transducer element, the one or more circuitries configured to enable: pulse transmission and reception of reflected signal for the ultrasonic transducer, where inductors are used to equalize impedance to obtain greater pressure output. Also disclosed are methods of altering a pressure of an ultrasonic wave emitted by an ultrasonic transducer.

Abstract: An ultrasonic imaging apparatus includes a plurality of transducers that transmit ultrasonic waves and a transmission unit that supplies drive signals to the plurality of transducers. An amplitude control voltage generation unit and a transmission circuit unit are connected to a common voltage power supply. An amplitude control voltage generation unit receives an output voltage of the voltage power supply and an attenuation degree setting signal instructing an attenuation degree of the drive signal for each of the transducers for weighting of the drive signal, and generates an amplitude control voltage corresponding to a voltage obtained by attenuating the output voltage by the attenuation degree. The output voltage of the voltage power supply is reduced to a voltage corresponding to the amplitude control voltage, and a drive signal having a predetermined waveform is generated whose amplitude is the voltage after the reduction for each of the transducers.

Abstract: Methods and systems are disclosed for determining pose information for at least one of a transmitter and receiver, both of which comprise ultrasonic transducers. A relative position is determined between the transmitter and the receiver and an orientation for at least is also determined. After obtaining field of view data for at least one of the transmitter and receiver, a field of view between them is determined, based at least in part on the field of view data, the determined relative position and the determined orientation. The pose information is then determined by weighting measurements of an ultrasonic signal emitted by the transmitter and received by the receiver based at least in part on the determined field of view relationship.

Abstract: In an image compressing ultrasound system, for generating an imaging sample, delays are applied transducer-element-wise to respective time samples. The delayed samples are summed coherently in time, the coherently summed delays being collectively non-focused. An image is sparsified based on imaging samples and, otherwise than merely via said imaging samples, on angles (236) upon which respectively the delays for the generating of the imaging samples are functionally dependent. An image-compressing processor (120) may minimize a first p-norm of a first matrix which is a product of two matrices the content of one representing the image in a compression basis. The minimizing is subject to a constraint that a second p-norm of a difference between a measurement matrix and a product of an image-to-measurement-basis transformation matrix, an image representation dictionary matrix, and the matrix representing the image in the compression basis does not exceed an allowed-error threshold.

Abstract: The invention provides a method for generating a filtered ultrasound image. The method begins by obtaining channel data. First and second apodization functions are applied to the channel data to generate first (610) and second (620) image data, respectively. A minimization function is then applied to the first (610) and second (620) image data, which may then be used to generate third (630) image data. The filtered ultrasound image may then be generated based on the first (610) and third (630) image data.

Abstract: The present invention discloses a method for determining an effective sound velocity in the deep sea. The method is applied to an apparatus for determining an effective sound velocity in the deep sea having a transmission point, a receiving point, and an underwater mobile carrier. The transmission point is installed on the sea surface such that the depth of the transmission point is unchanged. The receiving point is installed on the underwater mobile carrier such that the depth of the receiving point changes with movement of the underwater mobile carrier. The underwater mobile carrier can measure a sound velocity profile between the transmission point and the receiving point and a horizontal distance between the transmission point and the receiving point.

Abstract: A survey system and method to improve one or more of survey quality, efficiency, and utility for example by utilizing a vessel mounted MBES and a selected survey plan to check sound speed(s) via eliciting echoes from reflectors in colocated groups of reflectors using multi-perspective ensonification.

Abstract: This disclosure describes a full-face type mask for underwater use. The mask is provided with a mouthpiece to enable the wearer to breathe with his/her head under the surface of the water. The mask is also provided with a communication device.

Abstract: An ultrasonic device includes an ultrasonic transceiver that transmits an ultrasonic wave to a target at a predetermined interval, and that receives the ultrasonic wave reflected on the target so as to output a reception signal, a signal integration unit that outputs an integrated signal obtained by integrating the reception signals output within a predetermined period, and a position detection unit that detects a position of the target, based on a magnitude relationship between signal intensity of the integrated signal and a predetermined reference value.

Abstract: An initial gather of blended seismic signals induced in a common seismic receiver by a plurality of actual sources grouped in actual source groups is provided. Each actual source group has a linear source geometry that is the same for each actual source group. The plurality of sources in each actual source group is fired according to a pre-selected firing sequence that is the same for each actual source group. Actual shot records are created from the blended signals, and fictive shot records are created of seismic signals for fictive source groups that each have the same source geometry as the actual source groups, by interpolation of the actual shot records. Single source shot records of single source signals are separated by discrete deconvolution of the actual shot records and the fictive shot records. The output includes a seismic gather comprising a plurality of the single source shot records.

Abstract: Aspects of the technology described herein relate to an ultrasound device including a first die that includes an ultrasonic transducer, a first application-specific integrated circuit (ASIC) that is bonded to the first die and includes a pulser, and a second ASIC in communication with the second ASIC that includes integrated digital receive circuitry. In some embodiments, the first ASIC may be bonded to the second ASIC and the second ASIC may include analog processing circuitry and an analog-to-digital converter. In such embodiments, the second ASIC may include a through-silicon via (TSV) facilitating communication between the first ASIC and the second ASIC. In some embodiments, SERDES circuitry facilitates communication between the first ASIC and the second ASIC and the first ASIC includes analog processing circuitry and an analog-to-digital converter. In some embodiments, the technology node of the first ASIC is different from the technology node of the second ASIC.

Abstract: A processor in an ultrasound imaging system identifies faults or errors in the system. In one embodiment, fault or error conditions are detected by monitoring system parameters during a self-test. In another embodiment, a processor provides ultrasound image data to a trained neural network to identify fault conditions in a transducer or the imaging system. In some embodiments, the processor makes adjustments to one or more operating parameters to compensate for the identified fault conditions so that the system continues to operate and produce images with the detected fault condition.