Abstract: The ultrasonic homing assembly includes a base unit that may be coupled to a boat anchor. A base processor is coupled to the base unit. A transmitter is coupled to the base unit. The transmitter is operationally coupled to the processor. The transmitter transmits a location signal. A remote unit may be worn by a diver. A remote processor is coupled to the remote unit. A receiver is coupled to the remote unit. The receiver is operationally coupled to the remote processor. The receiver receives the location signal from the transmitter. A display is coupled to the remote unit. The display is operationally coupled to the processor. The display directs the diver toward the base unit. The diver swims toward the boat anchor.

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: An indoor ultrasonic location tracking system that can utilize standard audio speakers to provide indoor ranging information to modern mobile devices like smartphones and tablets. The method uses a communication scheme based on linearly increasing frequency modulated chirps in the audio bandwidth just above the human hearing frequency range where mobile devices are still sensitive. The method uses gradual frequency and amplitude changes that minimize human perceivable (psychoacoustic) artifacts derived from the non-ideal impulse response of audio speakers. Chirps also benefit from Pulse Compression, which improves ranging resolution and resilience to both Doppler shifts and multi-path propagation that plague indoor environments. The method supports the decoding of multiple unique identifier packets simultaneously. A Time-Difference-of-Arrival pseudo-ranging technique allows for localization without explicit synchronization with the broadcasting infrastructure.

Abstract: An elongate probe (204) including a probe head (214) with a transducer array (216), a shaft (210) and an articulating member (212). The articulating member is located between the probe head and the shaft. The articulating member is configured to articulate between a position in which the probe head extends along a longitudinal axis of the probe and at least one articulated position in which the probe head extends at a non-zero angle from the longitudinal axis of the probe. The probe further includes a stiffener (224) configured to controllably move from a retracted position to an extended position at which the stiffener inhibits articulation of the articulating member.

Abstract: A tool is described for seismic data collection which may have sensors mounted along its entire length to sample both geophysical signal and noise including at least one of acoustic noise, system noise, and noise resulting from the interaction between the two. Systems and methods for acquiring borehole seismic data are also described. In contrast to conventional systems which attempt to avoid introducing noise into the collected data stream, the present systems include a sufficient type, number, and spacing of sensors to intentionally sample at least one source of noise. The methods include operating a borehole seismic acquisition system to sample both a target signal and at least one source of noise and using a processor with machine-readable instructions for separating the noise from the signal.

Abstract: Two or more images are taken wherein during the image taking a focal sweep is performed. The exposure intensity is modulated during the focal sweep and done so differently for the images. This modulation provides for a watermarking of depth information in the images. The difference in exposure during the sweep watermarks the depth information differently in the images. By comparing the images a depth map for the images can be calculated. A camera system has a lens and a sensor and a means for performing a focal sweep and means for modulating the exposure intensity during the focal sweep. Modulating the exposure intensity can be done by modulating a light source or the focal sweep or modulating the transparency of a transparent medium in the light path.

Abstract: An optical measurement system includes a photodetector coupled in series with a field effect transistor (FET) that is a part of a sample and hold circuit. When the sample and hold circuit is in a sampling mode of operation, a voltage bias is applied to the FET and the photodetector is exposed to ambient light, thus resulting in a first current flow through the photodetector. One of several components can be selected in the sample and hold circuit for obtaining a desired time constant. When the sample and hold circuit is subsequently placed in a hold mode of operation, a second current flows through the photodetector due to exposing of the photodetector to a combination of ambient light and light associated with an optical measurement. A portion of the second current that is attributable to the light associated with the optical measurement is used for executing the optical measurement.

Abstract: Methods and systems for efficiently acquiring towed streamer marine seismic data are described. One method and system comprises positioning a plurality of source-only tow vessels and one or more source-streamer tow vessels to acquire a wide- and/or full-azimuth seismic survey without need for the spread to repeat a path once traversed. Another method and system allows surveying a sub-sea geologic feature using a marine seismic spread, the spread smartly negotiating at least one turn during the surveying, and shooting and recording during the turn. This abstract is provided to comply with the rules requiring an abstract, allowing a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A position information providing apparatus for providing present position information to a position notifier apparatus is provided. The position information providing apparatus includes an ultrasonic wave output device for outputting ultrasonic wave and a controller for controlling the ultrasonic wave output device. In accordance with contents of the present position information, the controller sequentially selects a modulation frequency from among multiple detectable frequencies which are detectable by the position notifier apparatus and which are lower than an ultrasonic wave frequency. The controller controls the ultrasonic wave output device so that a maximum value or a minimum value of amplitude of the ultrasonic wave varies with to the selected modulation frequency.

Abstract: Embodiments related to restriction of gas flow in a marine acoustic vibrator to compensate for gas spring effects. An embodiment provides a marine acoustic vibrator, comprising: an outer shell; and a variable gas flow restrictor disposed within the outer shell; wherein the marine acoustic vibrator has a resonance frequency selectable based at least in part on the variable gas flow restrictor.

Abstract: The present invention relates to an ultrasonic sensor for detecting double sheets and a method of detecting double sheets using the same, in which in configuring the ultrasonic sensor for detecting double sheets of banknotes passing through a transfer path, the ultrasonic sensor is configured to include an ultrasonic wave generator and an ultrasonic wave receiver provided in pair to face each other in a direction perpendicular to a transfer direction of the banknotes with the transfer path for transferring the banknotes interposed therebetween, and periodicity of a reception signal detected by the ultrasonic wave receiver is determined to detect whether a zero sheet, a single sheet or double sheets of the banknotes pass through the transfer path according to generation or not of the periodic signal and/or a frequency of the generation.

Abstract: Computational systems and methods for interpolating a pressure wavefield based on pressure wavefield and particle motion wavefield data are disclosed. The pressure and particle motion wavefields are sampled at a sample rate that is less than a lower bound for sample rates typically used to interpolate the pressure wavefield from the pressure wavefield samples alone. The particle motion wavefield can an acceleration wavefield or a time derivative of a velocity wavefield.

Abstract: Use of sonar systems to collect dimensional and relational data for use in metrology, mapping, object and structure detection, survey and evaluation applications is disclosed. Systems and methods for collecting underwater data sets, using registration targets, for data registration of underwater acoustic data sets, as well as for data registration of underwater acoustic data sets with above-the-waterline data sets (e.g., laser-based data sets) are described.

Abstract: Methods, systems, apparatuses, and computer program products are provided for creating multiple patterns of flood illumination for a time of flight (TOF) camera system. Light is generated, and from the generated light, illumination light is formed that is projected into an image environment. The illumination light is formed by: diverging the generated light to form divergent light characterized by a light profile that is less intense in a first region centered on an optical axis of the divergent light than in a second region that at least partially rings the first region, and converting the divergent light into a plurality of illumination light patterns to be projected into the illumination environment. The illumination light patterns are each projected to a corresponding region of the illumination environment.

Abstract: Variable depth multicomponent sensor streamer. At least some of example embodiments including perform a geophysical survey by: setting a first target depth for first depth positioning device of a sensor streamer, the first depth positioning device associated with a first sensor of the sensor streamer, the first sensor at a first offset, and the first target depth based on tension in the sensor streamer proximate the first sensor; setting a second target depth for a second depth positioning device of the sensor streamer, the second depth positioning device associated with a second sensor of the sensor streamer, the second sensor at a second offset greater than the first offset, the second target depth based on tension in the sensor streamer proximate the second sensor, and the second target depth greater than the first target depth; towing the sensor streamer through the water; and obtaining data from the sensors.

Abstract: Determination of an impulse response at a subsurface image level can include extrapolation of an up-going pressure wavefield to a subsurface image level, extrapolation of a down-going velocity wavefield to the subsurface image level, and determination of the impulse response at the subsurface image level from a hypothetical seismic source by spectral division of the extrapolated up-going pressure wavefield by the extrapolated down-going velocity wavefield.

Abstract: Laser light pulsed to illuminate and reflect from at least one object is received at a digital micro-mirror device including an array of mirrors each of which may be selectively controlled to be oriented to either reflect incident light onto a detector or not. The detector outputs a signal representative of an amount of light sensed. By applying M spatial patterns to the mirrors, each in synchronization with one pulse from the laser, and storing sampled signal values from the detector output at each of K times following a pulse from the laser, the collected information may be used to reconstruct K images each using all M spatial patterns and stored sampled signal values corresponding to a respective one of the K times. Each of the K images corresponds to a different range to the digital micro-mirror device, such that the system may be employed as a range finder.

Abstract: A method of calculating, using a depth sensor, a distance excluding an ambiguity distance including outputting a modulated light signal output from a light source to an object, receiving the modulated light signal reflected by the object, calculating a distance between the light source and the object using the reflected modulated light signal input to photo gates in conjunction with demodulation signals supplied to the photo gates, the calculating including calculating, using the modulated light signal, at least one distance farther than a maximum measurable distance, and setting the at least one distance to be equal to the maximum measurable distance may be provided. A range of the distance farther than the maximum measurable distance can be determined according to a duty ratio of the modulated light signal.

Abstract: Disclosed is a marine environment display device for georeferencing an image stream of a marine environment captured by a camera. The marine environment display device may comprise an image receiver configured to receive an image of the image stream from the camera, a location receiver configured to receive an object location of an object, an image generator configured to generate, from the image, a projected image having location information associated with each of a plurality of points on the projected image and corresponding to a camera position and field of view of the camera, an object generator configured to generate an object indicator at a position on the projected image based on the object location and the location information, and a display configured to display the projected image and the object indicator at the position on the projected image.

Abstract: Apparatus and methods for velocity scanning in, e.g., bodies of water. In one embodiment, a scanned one-dimensional transducer array Doppler sonar arrangement is used to remotely measure both vertical and horizontal profiles of a river or channel along-stream water velocities within a cross-section of the river/channel from a single side-mounted sonar.