Abstract: Disclosed sensors, sensor controllers, and sensor control methods enhance transducer performance using a model-based equalization method that can be performed in the field. One illustrative method for operating a piezoelectric-based sensor includes: sensing a response of a piezoelectric transducer as a function of frequency; deriving parameter values of an equivalent circuit for the piezoelectric transducer from the response; using a squared magnitude of the equivalent circuit's transfer function to determine a system level selectivity; and adapting at least one operating parameter of the sensor based on the system level selectivity. One illustrative controller for a piezoelectric transducer includes: a transmitter that drives the piezoelectric transducer; a receiver that senses a response of the piezoelectric transducer; and a processing circuit coupled to the transmitter and to the receiver to calibrate the transducer using the foregoing method.

Abstract: An underwater acoustic communication system includes a transmission device including N transmitters, and a reception device. The reception device includes M (M is an integer of two or more) receivers configured to receive M reception signal sequences corresponding to N transmission signal sequences transmitted from the N transmitters through sound waves, a beam former configured to suppress multipath waves other than direct waves of the M received reception signal sequences and to generate L (L is an integer of two or more) signal sequences from the M reception signal sequences, and a signal estimation unit configured to estimate the N transmission signal sequences based on the L generated signal sequences.

Abstract: A signal processing device includes: a data receiver configured to transmit a transmission wave a position of which changes in a first direction and which spreads in a second direction orthogonal to the first direction, and generate a matrix of acquired observation data in the first and second directions, as a reception signal matrix, with a value of a position in the reception signal depending on a signal strength; a range processor configured to specify a range in the second direction in an imaging matrix, and set a sparse vector including a component in the first direction of the specified range; a reconstruction processor configured to perform reconstruction processing using the reception signal matrix and the sparse vector to calculate a component of the sparse vector; and a synthesis processor configured to synthesize the resulting sparse vector while moving the range, to generate an imaging matrix.

Abstract: An underwater positioning system comprises a plurality of underwater beacons. A beacon, in response to a signal sent by an underwater vehicle, responds with a signal comprising one or more characteristics to identify the beacon. Components of an access algorithm are provided to the underwater vehicle. The access algorithm determines a location of the beacon based on the beacon's identity. A position of the vehicle is determined based at least in part on the location of the beacon.

Abstract: A sonar system includes a towfish comprising a first body linked to a second body, the first body being elongate along a longitudinal axis and comprising a plurality of acoustic transmitters distributed along the longitudinal axis, the sonar system comprising a cable linked to the second body and via which a surface carrier ship is intended to tow the towfish, the first body being mounted to pivot, with respect to the second body, about an axis of rotation so that, the first body can switch, by pivoting with respect to the second body about the axis of rotation, from an operational position to a capture position; the axis of rotation being substantially an axis of movement of the towfish, the longitudinal axis being substantially vertical in the operational position of the first body and being substantially horizontal in the capture position of the first body, when the towfish is totally submerged and towed by the carrier ship.

Abstract: A wave detector integrated device includes a support, protective shell and mode converter. The protective shell is installed on the support and rotates by the mode converter, and has a hollow cylindrical structure. A seismic source hammer is suspended at a protective shell central axis position. Electromagnetic accelerators are installed in a bus direction of the protective shell, and the seismic source hammer is connected with the electromagnetic accelerators. A drill bit type wireless transmission wave detector or standby flat bottom type wave detector is connected above the protective shell through a second telescopic rod having a driving device therein and driving the drill bit type wave detector to rotate. A power supply is installed inside the protective shell, and is connected with a current controller and circuit protection device. The current controller is respectively connected with the electromagnetic accelerators, drill bit type wave detector, driving device and mode converter.

Abstract: Technologies for processing a three-dimensional (3D) underwater scene is disclosed. A computing device receives a data set representative of an underwater environment corresponding to sonar data generated by a sonar transducer assembly and receiving parameters. The data set includes 3D volumetric points representative of at least one 3D volumetric data set at one or more time points. The computing device applies segmentation modes on the data set, in which each segmentation mode generates a processed subset of the 3D volumetric points. Each processed subset includes one or more 3D volumetric objects. The computing device classifies one or more 3D volumetric objects based on a combination of the plurality of processed subsets.

Abstract: Techniques of present disclosure are directed to methods of providing acoustic communication networks. For example, methods are provided for that include obtaining, at a first transceiver of a plurality of transceivers arranged within an installation pattern, a first acoustic signal provided by a second transceiver of the plurality of transceivers. A location of the first transceiver within a message distribution pattern is determined from the acoustic signal. A delay based upon the location of the first transceiver within the message distribution pattern is determined. Finally, a second acoustic signal corresponding to the first acoustic signal is provided from the first transceiver after the delay.

Abstract: An ultrasonic apparatus includes a transmitting circuit, an ultrasonic transducer, a receiving circuit, and a capacitance measuring circuit. The ultrasonic transducer is a three-terminal ultrasonic transducer that includes a transmitting electrode, a receiving electrode, and a common electrode. The transmitting circuit outputs a driving signal to the transmitting electrode to cause the ultrasonic transducer to transmit ultrasonic waves. The receiving circuit receives a receive signal from the receiving electrode. The capacitance measuring circuit is electrically connected to the receiving electrode to measure the electrostatic capacitance of the ultrasonic transducer.

Abstract: Disclosed is an electronic device that includes a display, a communication module, at least one microphone, at least one speaker, a processor operatively coupled to the display, the communication module, the microphone, and the speaker, and a memory operatively coupled to the processor. The memory may store instructions, when executed, causing the processor to transmit, through the speaker, a first audio sound including first information, receive, through the microphone, a second audio sound including second information responding to the first information from a first external electronic device, transmit, through the speaker, a third audio sound including third information for acquiring a distance to the first external electronic device after receiving the second audio sound, and receive, through the microphone, a fourth audio sound including fourth information responding to the third information from the first external electronic device.

Abstract: Aspects of the subject technology relate to a system including a reference device, a measurement device and a processor. The measurement device provides a three-dimensional (3-D) point map corresponding to first positions of a plurality of selected points on a torso of a user. The processor determines a shape of the torso based on the 3-D point map. The measurement device is sequentially placed on the plurality of selected points, and the 3-D point map represents the first positions of the plurality of selected points relative to a second position associated with a location in 3-D space of the reference device.

Abstract: This disclosure describes a system and method for generating images and location data of a subsurface object using existing infrastructure as a source. Many infrastructure objects (e.g., pipes, cables, conduits, wells, foundation structures) are constructed of rigid materials and have a known shape and location. Additionally these infrastructure objects can have exposed portions that are above or near the surface and readily accessible. A signal generator can be affixed to the exposed portion of the infrastructure object, which induces acoustic energy, or vibrations in the object. The object with affixed signal generator can then be used as a source in performing a subsurface imaging of subsurface objects, which are not exposed.

Abstract: An object detection device includes a signal generator configured to generate a drive signal including an identification signal for identifying ultrasonic waves, a transmitter configured to transmit an ultrasonic wave as a probe wave in response to the drive signal, a receiver configured to receive the ultrasonic wave to generate a reception signal, and a determiner configured to analyze frequencies of the reception signal to determine whether the received wave is a reflected wave of the probe wave, thereby detecting an object. The drive signal includes a ramp-up signal generated to be followed by the identification signal and is used to ramp up an amplitude of the probe wave. A frequency of the ramp-up signal is set to include a frequency at which a transmission/reception efficiency is higher than a transmission/reception efficiency at each of a maximum frequency of the identification signal and a minimum frequency of the identification signal.

Abstract: The present application provides a seafloor multi-wave seismic source including: a pressure chamber mechanism; a high-voltage pulse generator with four discharge pathways; a thrust mechanism with a thrust rod and a thrust head; four vibrators are evenly distributed around a periphery of the thrust head, and each vibrator is connected with one discharge pathway of the high-voltage pulse generator; a power supply unit to power the seismic source; and a processor, a memory and a program, wherein the program is stored in the memory and configured to be executed by the processor; and the program includes: pulse emission instructions generated by the processor based on user settings and received by the high-voltage pulse generator, for switching on four or any two of the four discharge pathways at the same time, to enable the corresponding vibrators to vibrate to excite seismic waves in compression wave mode or shear wave mode.

Abstract: A sound velocity profile inversion method based on an inverted multi-beam echometer.

Abstract: The present disclosure provides a system and method for removing noise from an ultrasonic signal using a generative adversarial network (GAN). The present disclosure provides three input formats for the neural network (NN) in order to feed one-dimensional (1D) input data to the network. The system is generalizable to multiple noise sources, as it learns from different motion functions and noise types. The end-to-end system of the present disclosure is trained on raw ultrasonic signals with very little pre-processing or feature extraction.

Abstract: Disclosed is an electronic device that includes a display, a communication module, at least one microphone, at least one speaker, a processor operatively coupled to the display, the communication module, the microphone, and the speaker, and a memory operatively coupled to the processor. The memory may store instructions, when executed, causing the processor to transmit, through the speaker, a first audio sound including first information, receive, through the microphone, a second audio sound including second information responding to the first information from a first external electronic device, transmit, through the speaker, a third audio sound including third information for acquiring a distance to the first external electronic device after receiving the second audio sound, and receive, through the microphone, a fourth audio sound including fourth information responding to the third information from the first external electronic device.

Abstract: A method for seismic surveying includes deploying a first seismic energy source at a plurality of locations along a source line. Locations are determined by, (i) setting a shot point at one end of the line, setting a minimum distance between shot points and setting a nominal shot point interval being greater than a Nyquist maximum spacing at a maximum spatial frequency to be evaluated in the subsurface area, (ii) calculating a maximum distance between shot points as a difference between twice the nominal shot point interval and the minimum distance, (iii) dividing a span between the maximum distance and the minimum distance into equally spaced samples, and choosing at random one of the equally spaced samples to calculate a shot point subsequent to the initial shot point; and (iv) setting the calculated shot point as the initial shot point and repeating (ii) and (iii) until the subsequent calculated shot point is within a predetermined distance of an opposed end of the first source line.

Abstract: A system includes first, second, and third microphones configured to receive sound waves from a source of the sound waves. The system includes a memory configured to store first, second, and third phase difference maps for the first and second microphones, the second and third microphones, and the third and first microphones. The system includes a processor configured to measure first, second, and third phase differences between the sound waves received from the source by the first and second microphones, the second and third microphones, and the third and first microphones; receive the first, second, and third phase difference maps from the memory; and identify a location of the source of the sound waves based on the first, second, and third phase differences and the first, second, and third phase difference maps for the first and second microphones, the second and third microphones, and the third and first microphones.

Abstract: The present invention provides a multi-mode dispersion energy imaging device and method for a four-component marine interface wave of an ocean bottom seismometer, belonging to the technical field of marine seismic exploration. The method includes the following steps: designing an marine interface wave artificial seismic observation system, designing a reasonable observation system according to the geological condition of the operation area to ensure the resolution of the imaging to perform the marine artificial source seismic operation carrying out the data preprocessing of the seafloor surface wave, and then carrying out the three-component seismometer Scholte wave and the acoustic guided wave dispersion energy imaging, and the one-component hydrophone acoustic guided wave dispersion energy imaging; superposing and normalizing the three-component Scholte wave dispersion energy spectrum and the one-component acoustic guided wave dispersion energy spectrum. The device is implemented based on the method above.