Abstract: A plurality of lead pins (2a-d) penetrates through a stem (1) having a circular shape and includes a signal lead pin (2a,2b). A block (4) is provided on an upper surface of the stem. A waveguide light receiving device (9) is provided on a side surface of the block. An amplifier (6) is provided on the side surface of the block and amplifies an electric signal output from the waveguide light receiving device. A first relay substrate is provided on the upper surface of the stem and arranged between the block and the signal lead pin. A first transmission line (12a,12b) is provided on the first relay substrate. A first wire (10f,10g) connects one end of the first transmission line and an output terminal of the amplifier. A second wire (10h,10i) connects the other end of the first transmission line (12a,12b) and the signal lead pin.

Abstract: Automotive radar systems may employ a reconfigurable connection of antennas to radar transmitters and/or receivers. An illustrative embodiment of an automotive radar system includes: a radar transmitter; a radar receiver; and a digital signal processor coupled to the radar receiver to detect reflections of a signal transmitted by the radar transmitter and to derive signal measurements therefrom. At least one of the radar transmitter and the radar receiver are switchable to provide the digital signal processor with signals from each of multiple combinations of transmit antenna and receive antenna.

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: Noise signals are captured from one or more physical error microphones located at first locations within the vehicle. High-frequency noise signals are captured from a feedforward system sensor. A virtual microphone algorithm is utilized to estimate noise signals at a virtual location based on the noise signals, the estimation utilizing a transfer function that estimates a signal that would have been received by the one or more physical error microphones at the virtual location. The virtual microphone algorithm is utilized to estimate noise signals at the virtual location based on the high-frequency noise signal. A noise-cancelling signal is provided to cancel noise at the virtual location, the noise-cancelling signal accounting for the noise captured by both the feedforward system sensor and the one or more physical error microphones, the ANC system utilizing a working frequency for the ANC of at least 2 kHz.

Abstract: A device can include a first circuit configured to be exposed to a first environment, the first circuit comprising one or more first transfer inductors, and a second circuit isolated from the first circuit and configured to be exposed to a second environment, the second circuit comprising one or more second transfer inductors. The second environment can be a harsh environment. The first circuit and the second circuit can be wirelessly coupled via the one or more first transfer inductors and the one or more second transfer inductors to allow transfer of power and/or signals between the first circuit and the second circuit.

Abstract: In order to stabilize the characteristics of reception of an optical signal received via a transfer path, this optical receiver is provided with: a local beam output means 1; a light receiving means 2; a photoelectric conversion means 3; a measuring means 4; a control means 5; and a comparing means 6, the comparing means 6, when the control means 5 sweeping the wavelength of the local beam in a predetermined wavelength range with respect to the central wavelength of the optical signal, generating difference data between a spectrum based on a result of the measuring, by the measuring means 4, of the electric signal in accordance with a change in the wavelength of the local beam and a preset reference spectrum.

Abstract: A method for indicating the presence of a buried person in a building after a collapse of the building may include repetitively monitoring a signal indicative of a presence of a person in at least one sensor disposed in or on a housing, and repetitively measuring an acceleration of the housing. The method may also include while the acceleration of the housing is smaller than or equal a predefined threshold value storing information indicating the presence of the person within the area in a memory module. The method may also include when the acceleration of the housing is larger than the predefined threshold value start repetitively sending the information indicating the presence of the person within the area into the surrounding space at least if the information indicates that a person is present within the area. An indication apparatus for use with the method may also be used.

Abstract: One example provides a time-of-flight depth imaging system configured to modulate light emitted from a light source to illuminate an environment with modulated light, and for each of one or more modulation frequencies, integrate an image at each phase step of a plurality of phase steps, and sense a temperature of the light source and/or image sensor via one or more temperature sensors to acquire a measured temperature. The instructions are further executable to, and for each pixel of one or more pixels of the image sensor, determine a complex phasor based upon the measured temperature using a linear inverse function for each modulation frequency, determine a phase shift between the light emitted from the light source and light from the light source reflected back by the environment based on the complex phasor, and output a depth value for the pixel based upon the phase shift.

Abstract: In industrial machine predictive maintenance system may include an industrial machine data analysis facility that generates streams of industrial machine health monitoring data by applying machine learning to data representative of conditions of portions of industrial machines received via a data collection network. The system may perform a method of sampling a signal at a streaming sample rate to produce a plurality of samples of the signal. Portions of the plurality of samples can be allocated to first and second signal analysis circuits based on signal analysis sampling rates less than the streaming sample rate, and the samples and the outputs of the signal analysis circuits can be stored. The system can include a sensor detecting a condition of an industrial machine to output a signal, which can be sampled at a streaming sample rate that is at least twice a dominant frequency of the signal.

Abstract: Systems and methods for identifying and locating target objects based on echo signature characteristics are disclosed. According to an aspect, a system includes a transmitter configured to transmit one or more mechanical waves to a target object for echo of the one or more mechanical waves by the target at a predetermined signature characteristic. The system also includes a detector configured to detect the echo. Further, the system includes a computing device configured to identify the predetermined signature characteristic of the detected echo for locating the target object.

Abstract: A failure detection system includes an omnidirectional microphone array device having a plurality of microphone elements and a directivity control device that calculates a delay time of a voice propagated from a sound source to each microphone element and forms a directivity of the voice using the delay time and the voice collected by the omnidirectional microphone array device, and detects a failure of the microphone element. A smoothing unit calculates an average power of one microphone element. An average calculator calculates a total average power of a plurality of usable microphone elements included in the omnidirectional microphone array device. A comparison unit compares whether or not a difference between the average power and the total average power exceeds a range of ±6 dB, and determines whether the microphone element is in failure based on the comparison result.

Abstract: An embodiment includes a non-transitory computer-readable medium with programming code executable by a processor to perform operations including accessing a scheduled time and teleconference contact information associated with a teleconference calendar event. The operations include determining whether an operator is operating a vehicle based on synchronization between a mobile device and an abstraction and communication device (device) interfaced with the vehicle. When an actual time is within a threshold of the scheduled time and the operator is operating the vehicle, the operations include determining whether the operator is a participant of a teleconference. If so, the operations include extracting the teleconference contact information from the teleconference calendar event. The operations include communicating a prompt to join the teleconference and receiving a confirmation to join the teleconference.

Abstract: A mobile device with an underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms. The portable device may be wearable.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: A circuit configuration for evaluating and/or for activating sound transducers for application in vehicles, particularly as a part of a parking assistance, the circuit configuration including a transformer having a primary winding and a secondary winding, and the windings lead to a transformation ratio of greater than 1, terminals being provided for a sound transducer at the secondary winding and terminals being provided at the primary winding for activating device(s) which generate a voltage that changes with time at the primary winding of the transformer; on the side of primary winding (primary side) an antenna being provided which is suitable for receiving electrical fields generated by interference signals, and which is connected to the side of secondary winding (secondary side) via a coupling path; a device for phase shifting being provided in the coupling path, which brings about a phase shift by 180° in the electrical interference signals received by the antenna.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater navigation system comprising a transmitter having an electrically insulted magnetic coupled antenna for transmitting an electromagnetic and/or magneto-inductive signal, a receiver having an electrically insulated magnetic coupled antenna for receiving an electromagnetic and/or magneto-inductive signal from the transmitter, and determining means for determining the position of the receiver relative to the transmitter using the received electromagnetic and/or magneto-inductive signal.

Abstract: In one embodiment, a method includes obtaining location information associated with a remote device, and processing the location information. Processing the location information includes determining if the remote device is mobile. The method also includes configuring a filter such that at least one parameter indicates that the remote device is mobile if the remote device is mobile, and configuring the filter such that the at least one parameter indicates that the remote device is approximately stationary if the remote device is not mobile. The filter is applied to the location information to generate a filtered location estimate which is arranged to estimate a location of the remote device.

Abstract: The present invention discloses a tagging and identification device and system for tracking and monitoring sea vessels as they enter sea ports, estuaries and/or other channels. The tagging device of the present invention comprises a receiver, for receiving an underwater electromagnetic signal transmitted by an underwater beacon. An acoustic transmitter is provided for transmitting an identification signal to an acoustic receiver deployed nearby. The acoustic identification signal is transmitted after an electromagnetic trigger signal is received from the underwater beacon. The tagging and device may further comprise a memory device which can store data relating to position and time of the see vessel to which it is attached. The tagging and identification device of the present invention is covert, compact and is capable of extended active deployment without replenishment of batteries etc.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: Light exposure may reduce the static charge inside a capacitive membrane transducer. For example, ultraviolet light shines on or in a cell. The light increases the energy of the charge carrier and/or ionizes gas in the cavity, allowing reverse migration or dissipation of the static charge.

Abstract: A method and a system for detection and position determination of chips, which transmit ultrasound signals in a room. The system comprises electronic identification chips, which are attached to objects that have to be monitored. Each chip is equipped with a transmitter and a receiver. The signals are received by a plurality of detector units, which are connected to a detector base unit that registers and interprets the signals transmitted form the identification chips. Detector base units located in different rooms are interconnected in a network and transmit processed information to one or more central units for further interpretation and sorting. The special feature of the invention is that line interference is substantially removed, and it is possible to determine position even though the identification chips are in motion.

Abstract: A method for providing an embellishment representation of a noise information is discloses.

Abstract: It is possible to establish an estimation method capable of logically and optimally deciding a forgetting coefficient and develop an estimation algorithm and a high-speed algorithm which are numerically stable. Firstly, a Processing section reads out or receives an upper limit value ?f from a storage section or an input section (S101). The.processing section decides a forgetting coefficient ? by equation (15) (S103). After this, according to the forgetting coefficient ?, the processing section executes a hyper H? filter of equations (10-13) (S105). The processing section (101) calculates the existence condition of equation (17) (or equation (18) which will be given later) (S107). When the existence condition is satisfied at all the times (S109), ?f is decreased by ?? and the same processing is repeated (S111).

Abstract: Low frequency vibration induced noise is reduced in a towed sonar array of the type comprising a number of oil-filled modules joined end to end with each module housing a plurality of hydrophones by arranging that the signal output from each hydrophone in an array is equally weighted at low frequencies to form a single channel. Beamforming is then carried out by applying different weights to the different module channels. High modulus internal strength members are included in each module to resist anti-phase vibration of the couplings at the end of the module. The hydrophone spacing and the coupling lengths are both made small compareed to the module length to improve vibration noise reduction.

Abstract: A noise control system is provided for controlling a noise level around a moveable target. The noise control system has a detecting system configured to detect a location and movement of the target, and a noise cancellation system. The noise cancellation system has a sensor for dynamically sensing noise at the location of the target. The noise cancellation system is configured to be responsive to detection of the location of the target by the detecting system and the sensed noise to provide a noise cancellation wave to a first space at and around the location of the target. The noise cancellation system is further configured to be responsive to detection of the movement of the target by the detecting system and the sensed noise, and to provide a noise cancellation wave to a second space to cover the moving target. The second space is larger than the first space.

Abstract: A system for measuring distance in a gas or liquid operating medium has an even number of ultrasonic signal transmitters (12, 14), and a single ultrasonic signal receiver (16). The ultrasonic signal transmitters are adapted to transmit ultrasonic signals to a target (18) in the operating medium. Each of the transmitters and receiver are so spaced apart in a geometrically symmetrical planar array within an acoustically attenuating substrate medium, and each of the transmitted ultrasonic signals are so pulse driven in an acoustically symmetrical relationship, that opposing ultrasonic signals transmitted through the substrate medium by symmetrically opposed transmitters are cancelled at the receiver and a signal for measuring distance to the target is formed at the receiver by combination of the transmitted signals through the operating medium.

Abstract: A method and apparatus is provided for suppressing noise which includes receiving a plurality of signals from an array of sensors and transforming each of these signals to the frequency domain. The transformed signals are beamformed so that noise sources can be identified by bearing and frequency range. A planewave-fit noise-suppression routine is then used to remove identified noise sources from the transformed signals and to provide a noise-suppressed transformed signal having signals from said identified noise sources suppressed.

Abstract: A scale adaptive filtering scheme is developed for underspread channels based on a model of the linear time varying channel operator as a process in scale. Recursions serve the purpose of adding detail to the filter estimate until a suitable measure of fidelity and complexity is achieved.

Abstract: A system and method for reducing acoustic, wind or other background noise that may interfere with sensing of a seismic signal is provided. More specifically, a shield is provided to enclose a geophone and thereby protect it from harmful noise. The shield may comprise a rigid shell, a structural damping material, an acoustically absorptive material, and a compliant seal for coupling the shield to the ground or reference surface.

Abstract: A sonar emits an ultrasonic wave into the water from a transducer on the basis of a transmission signal outputted from a transmission circuit, receives an echo reflected in the water with the transducer and converts the echo into an electric signal, and displays underwater information on a display unit on the basis of an echo signal extracted by processing the electric signal. A tailing signal removing unit for removing a tailing signal and extracting only the echo signal is provided in the sonar such that a video of a surface layer fish shoal is clearly displayed on a screen of the display unit without being hidden by a video of the tailing signal.

Abstract: From output of a microphone, a first circuit generates a signal having first directivity which passes, and a second circuit generates a signal having second directivity which conversely cuts off, a signal arriving from a direction of a target sound source to output the obtained signals to a third circuit. Here, with two microphones disposed such that a noise source such as a speaker fails to locate at a position of a null of the second directivity, at the output of the second circuit, a signal arriving from the direction of the target sound source is cut off and a signal arriving from the direction of the noise source is passed. The third circuit corrects the output of the first circuit to output a signal with a signal arriving from the direction of the target sound source emphasized and a signal arriving from the direction of the noise source suppressed.

Abstract: While keeping a propeller located in a negative direction of a y-axis turning, transmission of acoustic waves from vibrating elements of a transducer unit is interrupted. Reference signals “A” and “B” which are receiving beam signals having principal acoustic axes oriented in a propeller direction are generated from received signals obtained by “A” and “B” group vibrating elements, respectively. Next, adjustment factors used for removing propeller noise from received signals obtained by vibrating elements on positive and negative sides of an x-axis are calculated by performing arithmetic operation on time-series data on the received signals obtained by the positive and negative sides vibrating elements and on time-series data on the reference signals “A” and “B”, respectively.

Abstract: The present invention relates to a system and a method for substantially eliminating flow noise from the signal output of each hydrophone in a hull mounted acoustic array. The system comprises a plurality of hydrophones forming an acoustic array mounted to a hull of a marine vessel, at least one reference hydrophone mounted to the hull in a laminar region of fluid flow over the hull, and a computational device for generating an output signal for each hydrophone in the acoustic array which is substantially free of flow noise using signals inputted from the acoustic array hydrophones and the at least one reference hydrophone.

Abstract: An apparatus that produces a gaseous vapor baffle that isolates an undersea sonar system from acoustic noise. The apparatus allows for craft carrying undersea sonar systems to travel at relatively high speeds while substantially isolating the undersea sonar systems from acoustic noise interference produced by propulsion systems, hull appendages, waves and bubbles. The apparatus has a support strut that has one end that is joined or attached to the hull of a craft. A sonar pod is attached to the other end of the support strut. The support strut has a ventilation duct and a plurality of ventilation ports. A cavitator is attached to the support strut and produces a sheet cavity as the craft travels in the water. Pressurized air or other gases are injected into the ventilation duct which then exit through the ventilation ports and into the sheet cavity. The pressurized air or gas exiting the ventilation ports expands the sheet cavity to form a gaseous vapor baffle that isolates the sonar pod from acoustic noise.

Abstract: An ultrasonic sensor includes a piezoelectric vibrator, a reverberation measuring device and a compensating device. The piezoelectric vibrator vibrates to transmit an ultrasonic wave, receives a reflected wave of the transmitted ultrasonic wave and produces an output signal corresponding to vibration of the piezoelectric vibrator. The reverberation measuring device measures a reverberation period of the piezoelectric vibrator from the output signal. The compensating device compensates for an operation characteristic of the piezoelectric vibrator in accordance with the measured reverberation period. Thus, the ultrasonic sensor can decrease a reverberation period, which may cause reduction in detection accuracy and impossibility of detection of an obstacle at a short distance.

Abstract: A technique for suppressing interference with unknown phase shifts received by an array of sensor elements partitions the array into a plurality of subarrays. Each subarray is processed independently to suppress the interference. Next, the resulting data from each subarray are summed together. This summed data, which effectively represents data provided by the full array with interference suppressed, may be utilized to detect and/or localize a target of interest. Each subarray is processed independently of all other subarrays. No cross-subarray processing is required. This technique is applicable to linear arrays, multi-line arrays, planar arrays, cylindrical arrays, conformal arrays, and spherical arrays. Applicable sensors include acoustic sensors (e.g., sonar, ultrasonic), electromagnetic sensors (e.g. radar), and optical sensors (e.g., infrared, ultraviolet, visible light).