Abstract: A communication system (1) comprising a first and a second underwater wearable device to be worn by a swimmer at mutually distant locations is disclosed herein. The communication system is configured to derive information pertaining to the swimmer from properties of a version of the acoustic signal transmitted from a first communication module of the first underwater wearable device to a second communication module of the second underwater wearable device.

Abstract: Provided is a displacement sensor having a modular structure that allows further downsizing. A housing of a head is made up of a main housing and a lid member, both of which are precision molded products made of a metal material. A first holder to which a light projector is bonded and a second holder to which a light receiver is bonded are individually positioned on and bonded to the lid member. This work is performed by a mounting device. Optical components such as a light projecting lens are also bonded to the lid member, and the lid member modularized by incorporating such optical components is assembled and welded to the main housing.

Abstract: A synchronization wire for synchronizing sonar ping transmissions from sonar transducer elements or arrays is provided. The synchronization wire includes first and second connection points. The first connection point is configured to connect the synchronization wire to a first sonar module that is configured to control transmission of a first sonar ping from a first sonar transducer. The second connection point is configured to connect the synchronization wire to a second sonar module that is configured to control transmission of a second sonar ping from a second sonar transducer. The synchronization wire is configured to transfer an electrical current between the first and second sonar modules. The synchronization wire is configured to enable synchronization of the first and second sonar modules through the use of the electrical current. Processing circuitry in sonar modules may cause or prevent transmission of sonar pings based on the voltage level on the synchronization wire.

Abstract: An ultrasonic system includes an ultrasonic probe and a data processing unit which is physically separate from the ultrasonic probe, runs on an operating system and has a receiving memory and a transmission memory. A real-time bus system is for data coupling of the ultrasonic probe to the memories. A probe system manages data within the ultrasonic probe, the clock inaccuracy of the probe system is at least three orders of magnitude less than the clock inaccuracy of the real-time bus system. The response time of the operating system is at least two orders of magnitude longer than the clock inaccuracy of the real-time bus system. The real-time bus system is configured to transfer transmission data and received data simultaneously by uninterrupted streaming clocked with an on average constant rate during stateless operation of the ultrasonic probe, the operation not differentiating between transmission and receiving operation.

Abstract: A seismic sensor assembly can include a housing that defines a longitudinal axis; a sensor; sensor circuitry operatively coupled to the sensor; and overvoltage protection circuitry electrically coupled to the housing.

Abstract: A suppression of a rise in temperature is to be attained for a light source apparatus provided with an emission section in which a plurality of vertical-cavity surface-emitting laser light-emitting elements is arrayed. A light source apparatus according to the present technology includes an emission section in which a plurality of vertical-cavity surface-emitting laser light-emitting elements is arrayed, and a driving section configured to cause the plurality of light-emitting elements of the emission section to emit light, in which at least a portion of a region including driving elements in the driving section is disposed so as not to overlap with the emission section.

Abstract: The present disclosure belongs to the field of underwater target detection, and in particular, to a method for detecting a moving target based on spatial slices of transformed spatio-temporal frequency space.

Abstract: Sonar steering systems offering improved functionality and ease of use for an operator (e.g., an angler) are provided. A sonar steering system is configured to automatically adjust the directional coverage volume of the sonar system in a hands-free manner to allow the operator to focus on other tasks. Some such sonar steering systems are configured to adjust the directional coverage volume of the sonar transducers to maintain a target such as an area of interest (AOI) within the sonar display despite movement of the watercraft relative to the target. Accordingly, the coverage volume may be automatically adjusted to maintain the aim of the sonar transducers at a target that is moving through the water, such as a school of fish.

Abstract: A light detection and ranging system is provided using a first electromagnetic radiation of a first emitting structure as local oscillator signal for a second electromagnetic radiation received from the outside of the light detection and ranging system, wherein the first and second electromagnetic radiations are coherent and the resulting signal is detected by a detecting structure. The resulting signal corresponds to an information of a target at the outside of the light detection and ranging system.

Abstract: An interlaced data acquisition scheme is employed in an ultrasound imaging device to reduce the amount of electrical power consumed by the device's transmit firings when collecting video data. Reducing electrical consumption according to the present disclosure reduces battery size, weight and cost; reduces heat generation; reduces need for heat-dissipating materials in the probe and prolongs probe uptime. A reconstruction algorithm is employed to produce images from the interlaced data that are comparable in quality to videos that would be obtained by a conventional (non-interlaced) image acquisition.

Abstract: Computing devices, systems, and methods described in various embodiments herein may relate to light detection and ranging (LIDAR or lidar) systems. An example computing device could include a controller having at least one processor and at least one memory. The at least one processor is configured to execute program instructions stored in the at least one memory so as to carry out operations. The operations include receiving information indicative of transmit light emitted from a lidar system along a light-emission axis. The operations also include determining, based on the received information, a maximum instrumented distance. The maximum instrumented distance includes a known unobstructed region defined by a ray segment extending between the lidar system and a point along the light-emission axis.

Abstract: An electroacoustic transducer array 110 is described. The electroacoustic transducer array 110 comprises a first electroacoustic transducer 40A comprising a first active element 41A and a second electroacoustic transducer 40B comprising a second active element 41B. The electroacoustic transducer array 110 comprises an acoustic coupling layer 43 arranged to acoustically couple, in use, the first active element 41A and the second active element 41B to a transmission medium. The electroacoustic transducer array 110 comprises a first cavity 42A arranged between the first active element 41A and the acoustic coupling layer 43 to receive a first fluid; and/or a second cavity 42B arranged between the second active element 41B and the acoustic coupling layer 43 to receive a second fluid. In this way, acoustic coupling of the electroacoustic transducer array 110 and the transmission medium is improved.

Abstract: A location position system can include a plurality of beacons arranged a grid formation divided into a plurality of sub-grids. A mobile computing device can implement a location position application and can receive a radio signal from a particular beacon of the plurality of beacons. The radio signal can comprise a data component uniquely identifying the particular beacon, which can be used to identify a particular sub-grid of the plurality of sub-grids. An audio signal can be received from each of a set of sub-grid beacons associated with the particular sub-grid. Each audio signal can: (i) have a frequency in the frequency range of 16 kHz to 24 kHz and a transmission delay from a reference time, (ii) lack any additional identifying data, and (iii) be separately transmitted from the radio signal transmitted by the particular beacon. The mobile computing device can determine its position based on the received audio signals.

Abstract: An acoustic, preferably ultrasonic, wave emission and/or reception device, including a wave emitter configured to transmit waves at an emission frequency, and a receiver of preferably ultrasonic waves, separate from the emitter, having a resonance frequency, and configured to receive waves generated by the emitter and including direct waves and reflected waves, wherein the device includes a resonance frequency modulator of the receiver and a control unit configured to control the resonance frequency modulator during a predetermined time period, so as to reduce the sensitivity of the receiver during the predetermined time period by moving the resonance frequency of the receiver away from the emission frequency of the emitter. The acoustic device relates to the field of ultrasonic sensors, particularly PMUTs or CMUTs, having a high quality factor.

Abstract: A lidar, and an anti-interference method therefor, may modulate a transmitting time of the lidar by injecting random time jitter at a time interval in a sequence of the transmitting time, and cause the lidar to transmit a laser pulse according to a modulated transmitting time. When an echo received by the lidar includes an expected echo of the local lidar and an unexpected echo from other lidars, because the transmitting time and the expected receiving time of the echo are correlated, injecting random time jitter in the transmitting time of the lidar may disrupt the correlation between the transmitting time of the local lidar and the transmitting time of other lidars. Thus, when a plurality of lasers are used together in one scenario and cause crosstalk, the anti-interference method for the lidar above can be used to fight against crosstalk to some extent.

Abstract: The invention discloses a method for acoustic indoor positioning based on CDMA, which comprises: generating a BPSK signal; The BPSK signal was detected, the collected signal was de-carrierized and low-pass filtered, and then the data was down-sampled to the design code rate, and then the coarse position of the identification code was determined by the prefix code. Finally, the data with the same length as the identification code was intercepted from the data for matching filtering through the coarse position. Four base stations were designed in each area to obtain three TDOA observations generated by four TOA information, and the terminal position could be obtained through the three TDOA observations. Different areas are distinguished by different identification codes to achieve wide area coverage. The invention provides an effective means for accurate positioning in an indoor environment.

Abstract: An apparatus, a method, and computer-implemented media. The apparatus is to receive, simultaneously, electrical signals based on respective reflected frequencies of a reflected ultrasonic waveform reflected from a target object as a result of a transmitted ultrasonic waveform; compound information from the electrical signals to generate compounded electrical signals; and cause generation of an output image on a display based on the compounded electrical signals.

Abstract: A stern operatively mounted universal transducer for boat includes a mounting device, having upper and lower brackets, for securement to the boat, preferably its transom, the upper and lower brackets secure a drive cylinder, which when operative, lowers a drive rod for shifting a sonic transducer upwardly above the water, or downwardly into the water to scope the surrounding underwater typography. A pair of guide rods shiftably extend through the upper and lower brackets, and at their upper ends, secure to a motor and gear housing, the guide rods at their lower ends secure to a base plate. A transducer shaft extends into the motor housing which provides for its pivoting, and at its lower end, extends downwardly through the base plate, and secures a transducer mounting plate, to which the transducer is affixed, in preparation for its usage.

Abstract: Method for non-invasively characterizing a heterogeneous medium using ultrasound, comprising a step of generating a series of incident ultrasonic waves, a step of recording an experimental reflection matrix Rui(t) defined between the input emission basis (i) and an output reception basis (u), a step of determining a response REP(r,?r) of the medium between an input virtual transducer (TVin) calculated based on an input focusing of the experimental reflection matrix that creates an input focal spot around a first point (P1), and an output virtual transducer (TVout) calculated based on an output focusing of the experimental reflection matrix that creates an output focal spot around a second point (P2), said response being expressed as a function of a central point (PC) of spatial position (r) in the medium located midway between the first and second points (P1, P2).

Abstract: An optical device for determining a distance of a measurement object includes a LIDAR unit and a light sensor. The LIDAR unit has an illumination device to illuminate the measurement object and a measurement channel to detect a measurement beam reflected from the measurement object and to generate a LIDAR measurement signal. The light sensor has an optical source with a mode-locked laser to generate first and second frequency comb signals and splits the first frequency comb signal into a first measurement signal and a first reference signal and to illuminate the measurement object with the first measurement signal. The light sensor splits the second frequency comb signal into a second measurement signal and a second reference signal. An evaluation unit determines first distance information, evaluates signals detected by a measurement detector and a reference detector, generates a frequency spectrum, and determines second distance information of the measurement object.