Abstract: Disclosed are a directional acoustic sensor, a method of adjusting directional characteristics using the directional acoustic sensor, and a method of attenuating an acoustic signal in a specific direction using the directional acoustic sensor. The directional acoustic sensor includes a plurality of resonance units arranged to have different directionalities and a signal processor configured to adjust directional characteristics by calculating at least one of a sum of and a difference between outputs of the resonance units. In this state, the signal processor attenuates an acoustic signal in a specific direction by using a plurality of directional characteristics obtained by calculating at least one of the sum of and the difference between the outputs of the resonance units at a certain ratio.

Abstract: The disclosure relates to a method of determining at least a property of a material situated behind a casing of a borehole, wherein an image of a imaging parameter of the material, such as acoustic impedance, has been obtained. The method comprising identifying zones of the image corresponding to disturbance zones, based in particular on values of the imaging parameters or other measured parameters, deleting the data of the imaging parameter in each of the disturbance zones, reconstructing for each zone, data of the imaging parameter from the data of imaging parameter at the neighboring zones, and determining at least a property of the material based on the reconstructed image.

Abstract: Disclosed are a disturbance light identifying apparatus, a disturbance light separating apparatus, a disturbance light identifying method, and a disturbance light separating method capable of precisely identifying whether or not light exiting an optical system contains a disturbance light component or capable of separating such a disturbance light component by using a simple technique. Provided are: a modulated light irradiation unit that irradiates an optical system 1 with modulated light; a light receiving unit that receives light exiting the optical system 1 in response to an incidence of the modulated light from the modulated light irradiation unit; and a controlling unit that controls the modulated light irradiation unit and the light receiving unit.

Abstract: The disclosed system may include (1) a light source that emits light pulses into a field of view, (2) a light sensor array that captures light reflected from the field of view resulting from the light pulses, (3) a light control subsystem that (a) controls an emission timing of the light source and (b) controls a capture timing of the light sensor array relative to the emission timing of the light source, and (4) a depth measurement subsystem that generated depth measurements of at least some of the field of view based at least in part on output from the light sensor array, where operation of the light control subsystem is based at least in part on prior knowledge of the field of view. Various other methods and systems are also disclosed.

Abstract: Systems, devices, and methods for performing remote sensing using WMA. Embodiments include modulating an interrogation signal, transmitting the interrogation signal to a remote vibrating target, and receiving, at a first port of a WMA interferometer, a reflected signal. Embodiments also include splitting, by a first beam splitter, the reflected signal into first and second portions propagating down first and second waveguides, delaying, by a delay element, a phase of the reflected signal, and spatially phase shifting the reflected signal. Embodiments may further include splitting, by a second beam splitter, the first and second portions of the reflected signal into third and fourth portions propagating down the first and second waveguides, detecting an intensity difference between a first lobe and a second lobe of the third portion of the reflected signal, and calculating a Doppler frequency based on the intensity difference.

Abstract: A laser rangefinder and a method for implementing the same are provided. When the distance is measured, a number of laser signals are emitted from an emitting unit to an object to be measured. A receiving unit receives the laser signals reflected by the measured object and converts them into an electrical pulse signal. A time measuring unit converts a trigger signal of a laser emitter and the electric pulse signal converted by the laser receiver into a rectangular gate signal. The width of the rectangular gate signal is measured by a pulse counter unit with high precision.

Abstract: A method classifies dynamic or static objects in a surrounding area with a control device. Sound echoes are generated by at least one sensor over a defined time period. The sound echoes are emitted into the surrounding area, and are detected by the at least one sensor in order to acquire measurement data. The measurement data of the at least one sensor are received by the control device. The received measurement data are recorded in a two-dimensional array. At least one echo trace is extracted from the array. A relative speed of the detected sound echoes with respect to the at least one sensor is determined using a derivative over time of the measurement data of the array. The at least one echo trace is classified based on the determined relative speed.

Abstract: Vehicle-based distributed LIDAR apparatuses and methods. These apparatuses may include coherent fiber optic image bundles (CFOBs) that transfer laser reflections from several fields of view (FOVs) around the vehicle to a shared remotely located detector array, thereby enabling correlation of the original reflection directions with fiber locations within a bundle. These apparatuses may operate with a remotely located mirror (e.g. a convex roadside mirror); the apparatus and methods can track the mirror region as it moves in the local environment with an increased density of outgoing laser pulses and thereby interrogate the remote mirror for reflection data from a wide indirect field of view.

Abstract: A surveying instrument comprises a monopod installed on a reference point, a surveying instrument main body provided at a known distance from a lower end of the monopod and at a known angle with respect to an axis of the monopod and having a reference optical axis, wherein the surveying instrument main body performs an image pickup of an object to be measured and scans the object to be measured by a closed loop scan pattern respectively at a pre-rotation and a post-rotation of the surveying instrument main body, obtains cross points of a locus of a scan pattern of the pre-rotation and the post-rotation, obtains deflection angles of the cross point with respect to the reference optical axis of the pre-rotation and the post-rotation, and calculates a rotation angle of the surveying instrument main body based on a deviation between both of the deflection angles.

Abstract: Among other things, a method includes receiving first LiDAR point cloud information from a first LiDAR device and second LiDAR point cloud information from a second LiDAR device, generating third point cloud information according to merging the first and second LiDAR point cloud information, and operating the vehicle based upon the third LiDAR point cloud information.

Abstract: An ultrasonic transducer positionable in a wellbore environment may include a piezoelectric material layer, a protective layer, and connecting plate positioned between the piezoelectric material layer and the protective layer. The piezoelectric material layer may be formed as a plurality of columns of piezoelectric material for detecting a characteristic of the wellbore environment during a drilling operation. The protective layer may be positionable between the piezoelectric material layer and an acoustic medium in the wellbore environment. The connecting plate may be positioned between the piezoelectric material layer and the protective layer. The connecting plate may have a coefficient of thermal expansion (CTE) in a range between the CTE of the piezoelectric material layer and that of the protective layer, and an acoustic impedance in a range between the acoustic impedance of the piezoelectric material layer and that of the protective layer.

Abstract: An optical system is described, in particular for a LIDAR device, encompassing a lens and an objective for deflecting beams out of a scanning area or into the scanning area, the lens being designed as a lens array and the objective being situated in the beam path between the scanning area and the lens, the optical system encompassing at least one optical element situated ahead of the lens in the radiation direction or connected to the lens for adjusting an incidence direction of the radiation onto the lens array. Moreover, a LIDAR device is described.

Abstract: An ultrasonic transducer including a membrane film and a perforated baseplate. The baseplate can have a conductive surface with a plurality of perforations formed through the baseplate. The membrane film can have a conductive surface and be positioned under tension proximate to the perforations formed through the baseplate. The tension of the membrane film can be controlled to provide a restoring force to counteract the moving mass of the membrane film, and the moving mass of air in the perforations of the baseplate. By selecting the diameter(s) of the perforations of the baseplate, the thickness of the baseplate, the thickness of the membrane film, the tension of the membrane film, and/or the bending stiffness of the membrane film, a wide bandpass frequency response of the ultrasonic transducer centered at an ultrasonic frequency of interest can be obtained and tailored to a desired application.

Abstract: A foil for a towed cable includes a body defining at least two conduits. The body has a foil shape having a leading edge and a trailing edge. The foil shape defines a first surface extending between the leading edge and the trailing edge configured to provide lift. The foil shape defines a second surface opposed to the first surface extending between the leading edge and the trailing edge. The foil shape defines first and second lateral sides that extend between respective lateral edges of the first and second surfaces, the leading edge, and the trailing edge. A first conduit is defined within the forward half of the body adjacent to the leading edge, is open to each of the first and second lateral sides, and is configured to receive a cable therethrough. A second conduit may be defined within the body and filled with buoyant material.

Abstract: An unmanned aerial vehicle comprising a velocity sensing system is provided. The velocity sensing system comprises a transmitter configured to transmit a first acoustic signal having at least a first frequency and a receiver, configured to detect a second acoustic signal comprising the first acoustic signal after it has been reflected from a reflective surface. The velocity sensing system is configured to determine from the second acoustic signal a second frequency, said second frequency comprising the first frequency after having undergone a Doppler shift; and to use the first and second frequencies to determine a velocity at which the unmanned aerial vehicle is travelling relative to the reflective surface.

Abstract: A technique is provided to enable check of a calibrated condition of a total station (TS) having a laser scanner in a surveying site. The TS includes an optical system for sighting an object, a laser positioning part that irradiates the object with laser light via the optical system to position the object, and a plane crossing location identifying part that identifies a crossing location of multiple planes constituting a three-dimensional structure as a first location, on the basis of the positioning result from the laser positioning part. The TS also includes a laser scanner that performs laser scanning in an area containing the crossing location, a plane crossing location calculator that calculates the crossing location as a second location on the basis of laser scanning data from the laser scanner, and a comparing part that compares the first location and the second location with each other.

Abstract: A coding disc having a first surface and a second surface opposite to the first surface is provided. The coding disc includes a first aperture and a second aperture. The first aperture penetrates the coding disc from the first surface of the coding disc to the second surface of the coding disc. The first aperture has a first width. The second aperture penetrates the coding disc from the first surface of the coding disc to the second surface of the coding disc. The second aperture has a second width. The second width of the second aperture is different from the first width of the first aperture.

Abstract: A system is provided for determining the position of a mobile receiver unit in an environment. The system comprises: a transmission apparatus comprising a plurality of ultrasound transmitters configured to transmit a plurality of ultrasonic signals in different respective principal directions, each encoding a different respective direction identifier; a mobile receiver unit comprising an ultrasound receiver configured to receive the plurality of ultrasonic signals along a plurality of signal paths, at least one of which includes a reflection off an environment surface; and a processing system comprising a decoder arranged to decode the respective direction identifiers from the received signals.

Abstract: A technique for use in geophysical surveying includes imparting a plurality of humming seismic signals and a plurality of low-frequency seismic signals into a geological formation. The technique also includes receiving returned seismic energy of the plurality of humming seismic signals and the plurality of low-frequency seismic signals after interacting with the geological formation and recording the returned seismic energy.

Abstract: A method and apparatus for determining a direction of infrasound. Infrasound is received by a directional infrasound sensor comprising a plurality of channels and a plurality of sensor devices. Each channel in the plurality of channels comprises a single opening at a first end of the channel and a closed end opposite the opening. The opening of each channel in the plurality of channels is pointed in a different direction from the opening of each other channel in the plurality of channels. The plurality of sensor devices includes a sensor device at the closed end of each channel in the plurality of channels. Each sensor device in the plurality of sensor devices is configured to generate a sensor signal in response to pressure. The sensor signals generated by the plurality of sensor devices are processed to determine the direction of the infrasound received by the directional infrasound sensor.