Abstract: Disclosed are methods and systems for controlling spread and/or depth in a geophysical survey. An embodiment discloses a submersible deflector, comprising: an upper portion comprising an upper fin section and upper foils disposed below the upper fin section, wherein at least one slot is defined between the upper foils; and a lower portion coupled to the upper portion and disposed below the upper portion, wherein the lower portion comprises a lower fin section and lower foils disposed above the lower fin section, wherein at least one slot is defined between the lower foils. Also disclosed are marine geophysical survey systems and methods of performing geophysical surveys.

Abstract: A surface seismic survey is generated or obtained from Earth's surface and is based on time in which acoustic waves are reflected to Earth's surface. One or more tools measure density and sonic velocity of a subsurface formation. An estimate of acoustic impedance is obtained from the density and the sonic velocity to generate a synthetic seismic survey. The synthetic seismic survey and the surface seismic survey are compared and/or correlated. The acoustic impedance can be iteratively estimated until the synthetic seismic survey matches the surface seismic survey. Matching the surface seismic survey with the synthetic seismic survey may ensure that the surface seismic survey may be calibrated in actual depth.

Abstract: Sonar rendering systems and methods are described herein. One example is an apparatus that includes a transducer element, position sensing circuitry, processing circuitry, and a display device. The processing circuitry may be configured to receive raw sonar data and positioning data, convert the raw sonar data into range cell data based at least on amplitudes of the return echoes, make a location-based association between the raw sonar data and the positioning data, plot the range cell data based on respective positions derived from the positioning data and rotate the range cell data based on a direction of movement of the watercraft to generate adjusted range cell data. The processing circuitry may be further configured to convert the adjusted range cell data into sonar image data, and cause the display device to render the sonar image data with a presentation of a geographic map.

Abstract: An ultrasonic transducer device includes an ultrasonic element array and a common electrode wiring. The ultrasonic element array has three ultrasonic element rows with each of the three ultrasonic element rows including a plurality of ultrasonic elements arranged along a first direction and electrically connected to each other. The three ultrasonic element rows are arranged along a second direction intersecting with the first direction. The common electrode wiring is configured and arranged to supply a common voltage to at least one of the three ultrasonic element rows. The common electrode wiring extends in the first direction and is arranged between two of the three ultrasonic element rows positioned on outer sides among the three ultrasonic element rows with respect to the second direction.

Abstract: Computing device, computer instructions and method for deghosting seismic data related to a subsurface of a body of water. The method includes receiving seismic data recorded by seismic receivers that are towed by a vessel, wherein the seismic data is recorded in a time-space domain; modeling the seismic data in a shot or common midpoint domain as a function of operators to derive a model; using the derived model to remove the receiver ghost from the seismic data to obtain deghosted seismic data; and generating a final image of the subsurface based on the deghosted seismic data.

Abstract: A geophysical sensor cable has one or more sensor cable sections. Each of the sensor cable sections is provided with seismic and electromagnetic sensors arranged along said cable. The seismic sensors include a hydrophone and a seismic component receiver for seismic vector measurements while the sensor cable is at the sea-floor. The electromagnetic sensors include both E-field sensors and H-field sensors. The E-field sensors include pairs of first and second electrodes arranged with different positions along the cable and connected to a voltage amplifier. The H-field sensors include three mutually orthogonally arranged H-field component sensors.

Abstract: An ultrasonic sensor includes a transceiver device for transmitting and receiving ultrasonic waves; a circuit board mounted with an electronic circuit processing ultrasonic signals transmitted and received through the transceiver device; a housing including a device storing portion storing the transceiver device, a board storing portion storing the circuit board and a communication hole for bringing the device storing portion and the board storing portion into communication with each other, the board storing portion having an opening; and an electric connection unit extending through the communication hole to electrically interconnect the transceiver device and the circuit board. A cover member is installed in the opening of the board storing portion to hermetically seal the board storing portion.

Abstract: A method of determining the position of an underwater node. The positions of three or more transmitters are determined. Each transmitter transmits at least four pulses, wherein a time difference between each pulse and a previous one of the pulses is proportional to a respective co-ordinate of the position of the transmitter. The pulses are received at the underwater node and decoded by measuring the delays between them, thereby determining the co-ordinates of the transmitters. The range of each transmitter relative to the underwater node is also determined. Finally the position of the underwater node is determined in accordance with the co-ordinates and ranges. Any errors in the measurements of the delays between the pulses only translate into small errors in the determined position because of the proportionality between the delays and the coordinates. Therefore if there is a gradual decrease of signal-to-noise ratio then the accuracy of the position estimate also degrades gradually.

Abstract: An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

Abstract: A device including an emitter that transmits light in a series of frames, wherein each frame in the series includes at least one pulse. The device includes a receiver that receives, for each frame in the series, the at least one pulse reflected from a target, and generates, in response to receiving the at least one pulse in a current frame, an output for calculating a distance between the target and the device for the current frame. The device includes circuitry that calculates, for each frame in the series, the distance between the target and the device based on the receiver output. The circuitry dynamically controls a frame rate for each frame in the series based on the distance calculated in a frame immediately preceding the current frame, and controls the emitter such that the at least one pulse is emitted in the current frame at the calculated frame rate.

Abstract: A laser radar device has a light projection part that projects light to a monitoring area outside a vehicle from a vehicle interior through a glass surface, a light receiving part that is placed a given distance away from the light projection part in a substantially horizontal direction to receive reflected light from an object outside the vehicle in the light projected by the light projection part through the glass surface, a measuring part that measures the distance to the object in the monitoring area based on timing when the light projection part projects the light and timing when the light receiving part receives the reflected light, and a light-projection shielding part that shields the light projected to an outside of the monitoring area in the light projected by the light projection part.

Abstract: A position detection system, includes at least one moving body (MB) including a transmission device simultaneously emitting a trigger signal indicating transmission timing and an ultrasonic signal obtained by modulating a signal of a frequency as a reference by pseudo random sequence data having high self-correlativity, and a reception device detecting MB position. The reception device includes ultrasonic reception units, a unit calculating a correlation value between a waveform of the ultrasonic signal and a model waveform of the pseudo random sequence, a unit subjecting the waveform of the ultrasonic signal and the model waveform to calculate a correlation value between the two waveforms, a unit calculating a propagation time of each ultrasonic to arrive at each of the ultrasonic reception units from trigger signal reception to correlation peak detection, and a unit calculating MB position from the ultrasonic propagation time and the interval length between the ultrasonic reception units.

Abstract: A measurement system includes a signal generator producing an RF modulation frequency and sampling frequency and sending the sampling frequency to an ADC, and sending the RF frequency to modulate a first light source to produce a first light; an optical system sending a portion of the first light to a reference optical detector a portion of the first light out a measurement device to a target that returns a second light to the optical system which sends the second light to a measure optical detector, the reference and measure optical detectors converting the optical signals into corresponding electrical signals; a first ADC channel receiving the electrical measure signal and producing digital measure values; a second ADC channel receiving the electrical reference signal and producing digital reference values; and a processor receiving the digital measure and reference values and calculating the device to target distance.

Abstract: Methods and apparatus are presented for distance measurement using laser pulses in which at least one of an attenuation function and an offset of the attenuation function relative to the send pulse is variable to accommodate differing measurement needs. In some embodiments, at least one of an attenuation function and an offset of the attenuation function is fixed relative to the send pulse for some number of measurement cycles and information derived from the result is used to modify either or both of the attenuation function and offset of the attenuation function relative to the send pulse for subsequent measurement.

Abstract: Embodiments of the invention provide a barrier detection system that includes a plurality of sensors that are coupled in series to a seismograph. The seismograph receives a signal from the sensors. The system includes a computer system including computer storage and a processor. The computer system is in communication with the seismograph so that the computer system receives signals from seismograph and stores them in the computer storage. The system can include an object detection system that can process the signals received by the computer system from the seismograph. The object detection system can select a first portion of the signal to analyze based a predetermined time interval, create a baseline value for the first portion, and select a plurality of peaks from the first portion. The object detection can also analyze an amplitude, frequency, and periodicity of the first portion to assess the origin of the signal.

Abstract: The invention consists of a method which comprises a plurality of steps for determining difference in distance from a reference point to at least two sensor modules 10, 20 that are located under water. The sensor modules 10, 20 comprise means for sending and receiving acoustic signals to each other and to a hydrophone 30 at the reference point. Connected to the hydrophone 30 is a calculating unit 40 that utilises arrival time of the received signals from the sensor modules to determine difference in distance from the sensor modules 10, 20 to the reference point.

Abstract: Systems and methods for determining the location of a microphone by using sounds played from loudspeakers at known locations. Systems and methods may thereby require a minimal level of infrastructure, using sounds that would naturally be played in the environment. Systems and methods may thereby allow devices such as smart-phones, tablets, laptops or portable microphones to determine their location in indoor settings, where Global Positioning Satellite (GPS) systems may not work reliably.

Abstract: An ultrasonic detection device is constructed in such a way as to include a discriminating processing unit (a time width detecting part 13 and a pulse width discrimination part 14) for approximating the shape of each signal which is a reflection signal which is reflected from an object as a result of transmitting a ultrasonic pulse toward the object, or a noise as an isosceles triangle and computing a pulse time width equal to the length of the base of the approximating isosceles triangle, and for discriminating between the reflection signal and the noise signal by determining whether the computed pulse time width exceeds a predetermined pulse width discrimination threshold. Therefore, the ultrasonic detection device can determine the pulse time width with stability, and carry out the discriminating process with a high degree of reliability.

Abstract: Systems and apparatuses for interchangeable mounting options for a transducer housing are provided herein. Such a system may provide for easy change of mounting to a watercraft, such as between transom mounting, portable mounting, trolling motor mounting, and thru-hull mounting. A system for interchangeable mounting options of a sonar transducer to a watercraft may comprise at least one transducer, a transducer housing configured to house the at least one transducer, and a mount adapter. The transducer housing may comprise at least one upper engagement surface configured to adjacently engage the mount adapter to facilitate mounting. The at least one upper engagement surface may be configured to releasably engage the mount adapter to allow the mount adapter to be detached and removed without damaging or altering the transducer housing.

Abstract: There is provided herein a system and method of seismic data collection for land and marine data that utilizes narrowband to monochromatic low-frequency non-impulsive sources designed to optimize the ability of migration/inversion algorithms to image the subsurface of the Earth, in particular, full-waveform inversion.