Abstract: Methods and apparatus determining a position of a submersible vehicle within a body of water are provided. A method comprises determining an initial position of the vehicle while the vehicle is at or near a water surface. The method further comprises coupling the vehicle and a base node to a weight and determining a position of the base node once the base node and vehicle have reached the floor of the body of water using acoustic modems of the vehicle and a surface vessel to aid in calculating the position as they descend, and acoustically transferring the at rest position on the seafloor from the vehicle to the node. The method further comprises decoupling the vehicle from the node and weight and determining a position of the vehicle based on the position of the base node and acoustic signals exchanged between acoustic modems of the vehicle and the base node.

Abstract: Taps on a beam-interrupt button of an underwater signaling transceiver are encoded as binary frequency shift-key modulated Golay codes, which are transmitted via 56-58 kHz compression waves generated by a ring-shaped electromechanical transducer. Light emitting diodes flash to signal the content of received signals and provide monitoring of the distance between divers. All components of the transceiver—except outer portions of input/output leads and a suction cup for attaching to the transceiver to a diver's mask—are completely encased in transparent plastic. The input/output leads allow an internal battery to be recharged, provide access to the internal processor for programming and data retrieval, and monitor whether the transceiver is submerged so that the transceiver can operate in an underwater mode or an above-water mode. Transceivers only communicate with other transceivers which use the same communication channel.

Abstract: LiDAR (light detection and ranging) systems use one or more emitters and a detector array to cover a given field of view where the emitters each emit a single pulse or a multi-pulse packet of light that is sampled by the detector array. On each emitter cycle the detector array will sample the incoming signal intensity at the pre-determined sampling frequency that generates two or more samples per emitted light packet to allow for volumetric analysis of the retroreflected signal portion of each emitted light packet as reflected by one or more objects in the field of view and then received by each detector.

Abstract: An ultrasonic communication system comprising an enclosure, a first module and a second module is described. The enclosure has an internal surface, an external surface, and defines at least one metal channel. The first module comprises an ultrasonic transceiver disposed within the enclosure. The first module is positioned on the internal surface of the enclosure and is capable of transmitting and/or receiving modulated ultrasonic waves via the metal channel. The second module is positioned on the external surface of the enclosure and is adapted to transmit and/or receive modulated ultrasonic waves from the first module via the metal channel.

Abstract: Provided is a neuromorphic signal processing device for locating a sound source using a plurality of neuron circuits, the neuromorphic signal processing device including a detector configured to output a detected spiking signal using a detection neuron circuit corresponding to a predetermined time difference, in response to a first signal and a second signal containing an identical input spiking signal with respect to the predetermined time difference, for each of a plurality of predetermined frequency bands, a multiplexor configured to output a multiplexed spiking signal corresponding to the predetermined time difference based on a plurality of the detected spiking signals output from a plurality of neuron circuits corresponding to the plurality of frequency bands, and an integrator configured to output an integrated spiking signal corresponding to the predetermined time difference, based on a plurality of the multiplexed spiking signals corresponding to a plurality of predetermined time differences.

Abstract: A height measuring apparatus and a method thereof are disclosed. The disclosed method is suitable for an indoor environment. The disclosed method comprises emitting a first laser to a ceil via a first light path, determining whether a first reflective light corresponding to the first laser is received, emitting a second laser to an object via a second light path reflected by the ceil, determining whether a second reflective light corresponding to the second laser is received, calculating a first length according to a first data corresponding to the first reflective light, calculating a second length according to a second data corresponding to the second reflective light, and calculating an object height of the object according to the first length and the second length.

Abstract: Provided is an object information acquiring apparatus that generates image data inside an object on the basis of an acoustic wave propagating inside the object, which uses an object information acquiring apparatus having an acoustic detector receiving the acoustic wave, an object information distribution processor generating an object information distribution representing a property of inside of the object by using the acoustic wave, a reliability distribution generator generating a reliability distribution by using the object information distribution, a similarity distribution generator generating a similarity distribution indicating similarity between template data indicating a relation between a real image and an artifact in the image data, and the object information distribution, and a combination processor performing combination processing of the reliability distribution and the similarity distribution.

Abstract: An ultrasonic observation apparatus includes: a first conversion unit that converts an ultrasonic signal as a time domain signal reflected from a specimen into a frequency domain signal; a regression analysis unit that calculates a regression expression for the frequency domain signal; an attenuation correction coefficient calculation unit that calculates an attenuation correction coefficient which is obtained by dividing a difference between first-order coefficients in the regression expressions at two points having different reception depths by a difference between the reception depths at the two points; an attenuation correction processing unit that performs attenuation correction processing on the frequency domain signal based on the attenuation correction coefficient; a second conversion unit that converts the frequency domain signal after the attenuation correction processing, into a second time domain signal; and an image data generation unit that generates ultrasonic image data based on the second tim

Abstract: An optical device may include: an optical module disposed in a beam delivery path of a laser beam; a beam adjusting unit disposed in the beam delivery path for adjusting the beam delivery path of the laser beam; a measuring unit disposed in the beam delivery path for detecting the beam delivery path; and a control unit for controlling the beam adjusting unit based on a detection result of the beam delivery path of the laser beam detected by the measuring unit.

Abstract: A monolithic ultrasonic horn where the horn, backing, and pre-stress structures are combined in a single monolithic piece is disclosed. Pre-stress is applied by external flexure structures. The provision of the external flexures has numerous advantages including the elimination of the need for a pre-stress bolt. The removal of the pre-stress bolt eliminates potential internal electric discharge points in the actuator. In addition, it reduces the chances of mechanical failure in the actuator stacks that result from the free surface in the hole of conventional ring stacks. In addition, the removal of the stress bolt and the corresponding reduction in the overall number of parts reduces the overall complexity of the resulting ultrasonic horn actuator and simplifies the ease of the design, fabrication and integration of the actuator of the present invention into other structures.

Abstract: A method of determining locations of microseismic events caused by a hydrofracking process is disclosed. The method includes: measuring audio signals using an array of geophones deployed in a monitoring well during hydraulic fracturing; modifying the audio signals according to a predefined nonlinear distortion operator to generate a modified audio signal, wherein the modified audio signal has audible components in a predefined frequency range beyond a cutoff frequency defined by a sampling rate of the respective measured audio signals; and playing the modified audio signals through a stereo or multi-channel speaker system, wherein a user of the stereo or multi-channel speaker system is able to determine the locations of the microseismic events from listening to the modified audio signals.

Abstract: A system and method for a rangefinding instrument incorporating pulse and continuous wave signal generating and processing techniques for increased distance measurement accuracy. The use of the former technique effectively solves the ambiguity issues inherent in the latter while allowing for relatively simple circuit implementations. Thus, a potentially more accurate phase-based distance measurement technique can be utilized which is also completely independent of the maximum range to the target.

Abstract: An underwater detection system is provided that can effectively use a discrimination result. A fish detector of the system is configured to implement a discrimination function including a fish species discrimination function; however, a fish detector and a sonar of the system do not comprise such a discriminator including a fish species discriminator. The fish detector transmits various discrimination results such as fish species discrimination, etc., through an onboard LAN to the fish detector or the sonar. The fish detector and the sonar superimpose various received discrimination results on the detection result of the device itself and display them on a display.

Abstract: A device comprises: an emitting element for emitting a laser beam, referred to as an emitted beam; a focusing element for focusing the emitted beam at a predetermined focal distance (D); a receiving element for receiving the emitted beam after being reflected by a particle in the air (18), referred to as a reflected beam; a transmitting element for transmitting the signal of interference occurring between the emitted beam and the reflected beam to a signal processor in order to deduce the speed of the particle therefrom. The emitting element includes a laser diode and the receiving element is combined with the laser diode by self-mixing. The focal distance is between 5 cm and 2 m.

Abstract: Devices and techniques for combined forward and inverse synthetic aperture imaging LADAR (combined SAL) include scanning a non-stationary target with an optical signal emitted from a non-stationary laser source, receiving reflections of the signal on a receiver, and determining the combined synthetic aperture.

Abstract: A method of signal processing includes calculating a range based on information from a reflected ultrasonic signal. Based on the calculated range, one among a plurality of direction-of-arrival (DOA) estimation operations is selected. The method also includes performing the selected operation to calculate an estimated direction of arrival (DOA) of an audio-frequency component of a multichannel signal. Examples of DOA estimation operations include operations based on phase differences between channels of the multichannel signal and operations based on a difference in gain between signals that are based on channels of the multichannel signal.

Abstract: In seismic survey for icy waters, streamers are towed behind a vessel under the water's surface to avoid ice. GPS readings may not be consistently obtained because the ice prevents a tail buoy with a GPS receiver from trailing from streamer at the surface. Instead, a device tows on the streamer under the water's surface. The streamer's absolute position is tracked by intermittently bringing the towed device toward the surface so GPS readings can be obtained. The streamer's absolute position can then be used in conjunction with compass readings and can correlate various seismic sensor signals obtained along the streamer during the survey. The compass readings can be corrected for declination using declinometer readings, which can be compensated for iron effects from the vessel or other device carrying the declinometer.

Abstract: A method for generating synthetic seismic traces. The method includes receiving a hybrid model that includes geological and seismic data, where the geological data corresponds to a zone of interest and the seismic data corresponds to the zone of interest and adjacent areas of the zone of interest. The method may determine a plurality of reflection properties along a path for a trace location using data from the hybrid model. The method may then generate a synthetic seismic trace for the trace location using the plurality of reflection properties.

Abstract: Systems, methods, and apparatus for matching pair-wise differences (e.g., phase delay measurements) to an inventory of source direction candidates, and application of pair-wise source direction estimates, are described.

Abstract: A method controls a delay of an air-gun in an aquatic seismic source. The method includes a step of receiving an attribute of the air-gun during the aquatic seismic survey; a step of calculating, based on a time-delay algorithm that uses the attribute, the asynchronization time of the air-gun; a step of determining whether the asynchronization time is smaller than a given time threshold; a step of instructing a controller to (1) wait for a predetermined time before calculating again the asynchronization time of the air-gun if the asynchronization time is smaller than the given time threshold, or (2) calculate an updated asynchronization time for the air-gun based on the attribute if the asynchronization time is larger than the given time threshold; and a step of sending the updated asynchronization time to a gun controller of the air-gun for adjusting a delay time for firing the air-gun.