Abstract: An underwater detection apparatus is provided, which may include a transmission transducer, a reception transducer, and processing circuitry. The transmission transducer may transmit a transmission wave in an underwater transmission space. The reception transducer may include a plurality of reception elements, each reception element generating a reception signal based on a reflection wave comprising a reflection of the transmission wave on an underwater target. The processing circuitry may perform beamforming in each of a plurality of reception spaces based on the reception signals, generate a 3D image data of the target based on the beamforming performed in each reception space, and extract a contour of the target detected in at least one of the reception spaces, and generate a contour image data to be displayed along with the 3D image data on a display unit.

Abstract: Systems and methods directed toward acoustic analysis can include an acoustic sensor array comprising a plurality of acoustic sensor elements, an electromagnetic imaging tool, and a processor in communication with the acoustic sensor array and the electromagnetic imaging tool. The processor can be configured to analyze acoustic data to extract one or more acoustic parameters representative of acoustic signals at one or more locations in an acoustic scene and generate a display image that includes electromagnetic image data and acoustic image data. The display image can further include information indicative of the one or more acoustic parameters at one or more locations in the acoustic scene, such as including acoustic image data in the display image at locations in the scene at which the one or more acoustic parameters satisfies a predetermined condition.

Abstract: A method is provided to measure a modulus of complex sensitivity of hydrophone data channels using a quasi-diffuse sound field. In the method, a radiation pattern representing shallow water sources directs to a location as a direct acoustic path and sound reflects to the location from the water bottom as a reflected acoustic path. At least one hydrophone receives the sounds at the location as acoustic signals with an acoustic intensity being the sound intensities along the acoustic paths. The sound intensity at the hydrophones also relates to a zenith angle and a bottom intensity reflection coefficient. The modulus of the frequency dependent sensitivity of the hydrophone is computed from measurements of the voltage output and voltages of reference hydrophones with the sound intensity as factor and with uncertainty reduced by averaging hydrophone sensitivities.

Abstract: A fishfinder has: a transducer capable of transmitting an ultrasonic wave underwater and receiving a reflected wave of the ultrasonic wave; a display part that time-sequentially arranges a detection image based on a reception signal, caused by receiving the reflected wave with the transducer; a first depth calculation part that calculates a first depth as a depth of the bottom; a recognition part that performs recognition on an object as a fish school; a second depth calculation part that calculates a second depth as a depth of a position of the object; a distance calculation part that calculates a distance from the bottom to the position of the object; and a distance display part that displays the distance calculated with the distance calculation part, in correspondence with the position of the object in the detection image displayed on the display part, on the display part.

Abstract: The invention relates to hydroacoustic equipment and can be used in constructing hydroacoustic systems. Multifrequency sonar side viewer comprising display unit, control unit, n-input adder, connected in series radio-frequency pulse generator, switch, multielement transceiving interference antenna, differs because of antenna aperture is made as cylinder-shaped bay, convex towards echo search, with radius of curvature R, that has generatrix l in azimuth plane and that is way longer than a chord, that draws together uttermost symmetric, relatively to the acoustic axe, points of arc with L length. The invention expands operational capabilities of sonar side viewer, reducing dead zone and increasing dimension of explored bottom surface swath in echo search direction, due to the using of non-linear self-action soundwaves effect.

Abstract: An apparatus including a uniplanar sonar head. The uniplanar sonar head includes at least one probe element being configured to output cooperatively a unipolar spiral probe signal. The uniplanar sonar head includes at least one reference element being configured to output a circular reference signal. The uniplanar sonar head includes an acoustic receiver comprising an input channel being configured to receive a reflected unipolar spiral probe signal and a reflected circular reference signal. The apparatus includes a plurality of amplifiers communicating with the at least one probe element, the at least one reference element, and the acoustic receiver. The apparatus includes a processor cooperating with the plurality of amplifiers. The apparatus includes a computer-readable medium storing instructions including a target-detection method, which includes determining an angular position of the target based on the plurality of acoustic echoes received via the input channel.

Abstract: Described is a system for producing an acoustic field from a plurality of ultrasonic transducer arrays, each of which has known relative positions and orientations. The acoustic field comprises a carrier wave and a modulated wave. The carrier wave has a plurality of modulated focal areas. A plurality of control points having a known spatial relationship relative to at least one of the plurality of ultrasonic transducer arrays is used. The plurality of ultrasonic transducer arrays are calibrated by using the relative position of each of the plurality of ultrasonic transducer arrays.

Abstract: A marine vibrator may include a containment housing, a sound radiating surface, and a compliance chamber. The compliance chamber may include a compliance chamber housing, a non-linear linkage assembly, and a low pressure chamber. The compliance chamber housing may define at least a portion of a compliance chamber internal volume having a compliance chamber internal gas pressure. The low pressure chamber may comprise a low pressure piston and a low pressure chamber housing. The low pressure chamber housing may define at least a portion of a low pressure chamber internal volume having a low pressure chamber internal gas pressure. The low pressure piston may be configured to move in response to a pressure differential across the low pressure piston such that a resonance frequency of the marine vibrator may be changed.

Abstract: Provided is an electronic apparatus for detecting information about a target object by using an ultrasound wave. The electronic apparatus includes: a transmitter configured to emit an ultrasound wave modulated based on a predetermined code signal; a receiver configured to receive a reflected signal corresponding to the emitted ultrasound wave reflected from a target object; and a controller configured to acquire a reception signal from the received reflected signal and detect information about the target object based on a difference between correlation values corresponding to a plurality of predetermined periods of the reception signal and the predetermined code signal.

Abstract: An ultrasonic sensor includes an ultrasonic element and an element accommodation case. A side wall portion of the element accommodation case has a tubular shape surrounding a directional central axis. A bottom wall portion and a top wall portion of the element accommodation case cover ends of the side wall portion in a direction along the directional central axis. The top wall portion has a diaphragm portion. The bottom wall portion supports the ultrasonic element. For example, the ultrasonic element is opposed to the diaphragm portion across a gap defining an interval corresponding to an integral multiple of half of a wavelength of ultrasonic vibration. Alternatively, the diaphragm portion is formed of a material having an acoustic impedance of 50×105 Pa·s/m or more and 5000×105 Pa·s/m or less, and has a thickness of 1 mm or less.

Abstract: The present invention concerns a pulse wave image reconstruction method to be used for example in ultrasound imaging. The proposed method is based on an image measurement model and its adjoint operator. The proposed method introduces matrix-free formulations of the measurement model and its adjoint operator. The proposed method has the advantage that the reconstructed image has a very high quality and that it can be reconstructed quickly.

Abstract: A method for microphone selection, applied in a mobile device having at least two microphones, the method includes: transmitting, by using an ultrasonic transmitter of the mobile device, first ultrasonic waves within a testing box, wherein the first ultrasonic waves are transmitted with a predefined transmission strength and at different frequencies selected from a predefined frequency range; acquiring, by using each of the at least two microphones to receive second ultrasonic waves reflected from the first ultrasonic waves within the testing box, frequency response values of the second ultrasonic waves received by each of the at least two microphones; and determining one of the at least two microphones which has a highest frequency response value, as a microphone for receiving ultrasonic waves for the mobile device.

Abstract: Ultrasonic ranging systems and methods that emit coded bursts and correlate transduced acoustical echoes of the bursts with a receive template characterizing a burst code to determine time-of-flight information use receive templates of time-variable length to improve short-range object detection. The template length is based on a time index measured from the start of the burst emission. The detection can account for a dead zone of transducer ringing following a burst. A time-variable gain that is also based on the time index can be applied to the correlated signal. The length and gain can be adjusted with reduced temporal frequency to reduce computation cost.

Abstract: According to various embodiments, a system for acoustic to electronic transduction is disclosed. The system includes a transducing medium configured to convert a received acoustic signal into a transduced electronic signal when a voltage is applied. The system further includes a high-pass filter coupled to the transducing medium, the high-pass filter configured to isolate the transduced signal from the applied voltage.

Abstract: The ultrasonic diagnostic apparatus according to the embodiment includes regulator circuitry, transmission circuitry, and control circuitry. The regulator circuitry convert a power supply input in accordance with a driving pulse signal to generate an output signal. The transmission circuitry convert the output signal to a transmission pulse to drive a ultrasonic probe. The control circuitry generate a driving pulse signal to increase the output signal when allowing the transmission circuitry to generate a transmission pulse having a strength and/or a time width equal to or greater than a predetermined value, in comparison to when allowing the transmission circuitry to generate a transmission pulse having a strength and/or a time width equal to or less than the predetermined value.

Abstract: An ultrasonic sensor is secured to an attachment object and passes through the attachment object. The ultrasonic sensor includes an oscillator which has a transceiving surface which transmits or receives an ultrasonic wave, a cylindrical elastic member which surrounds an outer surface of the oscillator extending from the transceiving surface in a thickness-wise direction of the transceiving surface and has an inner surface contacting the outer surface of the oscillator, a body which has a housing with a bottom and in which the to oscillator and the elastic member are disposed except a protruding portion on a side of said transceiving surface, and an annular body which surrounds the protruding portion of the elastic member and is disposed in the body in contact with a front of the attachment object.

Abstract: Simultaneous sources are separated with a deblending method wherein the fullband data deblended on a source-by-source basis. The fullband data is first decomposed into multiple subbands, and then a non-equispaced subband Radon transform is used to transform the decomposed data into the Radon domain. The deblending process is solved subband by subband by minimising a nonlinear objective function. The solution of the nonlinear objective function is found using a multi-step procedure.

Abstract: A marine electronic device is provided including a user interface comprising a display, a marine electronic device processor, and a memory. The memory includes computer program code configured to cause the marine electronic device to receive sonar return data from at least one transducer element configured to transmit sound waves into a body of water, receive the sonar return signals from the body of water, and convert the sonar return signals into sonar return data. The computer program code is further configured to cause the marine electronic device to generate one or more sonar images based on the sonar return data, identify one or more degraded performance characteristics associated with the sonar return data or the one or more sonar images, and cause an alert based on identification of the one or more degraded performance characteristics.

Abstract: Example sonar transducer assemblies configured for reduced interference are provided herein. An example sonar transducer assembly includes a housing, a first transducer, and a second transducer. The first transducer is positioned within the housing such that a length is configured to extend in a first mounting plane and a produced first beam defining a fan-shape extends in a first plane. The second transducer is positioned at a tilted angle within the housing such that a length is configured to extend in a second mounting plane and a produced second beam defining a fan-shape is in a second plane. The second mounting plane is non-parallel to the first mounting plane and is offset from the first mounting plane by at least 1 degree such that the second plane is not parallel to the first plane so as to reduce interference between the first transducer and the second transducer.

Abstract: Simultaneous 2-D room shape reconstruction and self-localization is accomplished using no pre-established infrastructure. A mobile device with co-located microphone and loudspeaker is used to collect echoes reflected by the walls. The system uniquely recovers arbitrary 2-D convex room shape as well as the position of mobile device 10 by collecting and processing distances between three consecutive measurement points as well as acoustic echoes from the device. A practical algorithm for room shape reconstruction and self-localization in the presence of noise and higher order echoes is proposed. Experimental results are provided to demonstrate the effectiveness of the approach.