Abstract: A method and system to compensate for stray light errors in time of flight (TOF) camera systems uses reference targets in the in the field of view (FOV) that can be used to measure stray light. In different embodiments, one or more reference targets are used.

Abstract: A first photoelectric conversion element, which detects light and converts the light into photoelectrons has: one first MOS diode having a first electrode formed on a semiconductor base body with an insulator therebetween; and a plurality of second MOS diodes, each of which has a second electrode formed on the semiconductor base body with the insulator therebetween. The first electrode of the first MOS diode has, when viewed from the upper surface, a comb-like shape wherein a plurality of branch portions are branched from one electrode portion. Each second electrode of each of the second MOS diodes is, when viewed from the upper surface, separated from the first electrode, and is disposed to nest between the branch portions of the first electrode.

Abstract: Methods and systems for detecting weather conditions including sunlight using onboard vehicle sensors are described. In one example, a method is provided that includes receiving laser data collected for an environment of a vehicle. The method also includes associating laser data points with one or more objects in the environment, and determining given laser data points that are unassociated with the one or more objects in the environment as being representative of an untracked object at a given position with respect to the vehicle. The method also includes determining that the untracked object remains at a substantially same relative position with respect to the vehicle as the vehicle moves, and identifying by the computing device an indication that a weather condition of the environment of the vehicle is sunny.

Abstract: In illustrative implementations, a time-of-flight camera robustly measures scene depths, despite multipath interference. The camera emits amplitude modulated light. An FPGA sends at least two electrical signals, the first being to control modulation of radiant power of a light source and the second being a reference signal to control modulation of pixel gain in a light sensor. These signals are identical, except for time delays. These signals comprise binary codes that are m-sequences or other broadband codes. The correlation waveform is not sinusoidal. During measurements, only one fundamental modulation frequency is used. One or more computer processors solve a linear system by deconvolution, in order to recover an environmental function. Sparse deconvolution is used if the scene has only a few objects at a finite depth. Another algorithm, such as Wiener deconvolution, is used is the scene has global illumination or a scattering media.

Abstract: A time-of-flight (TOF) sensor pixel is provided that performs in-pixel subtraction. The TOF sensor pixel includes a photodetector, a capacitor, and circuitry. The photodetector detects light pulses emitted at a clock frequency, after a time of flight, to provide a photocurrent. The capacitor integrates the photocurrent over an integration period, while the circuitry reverses a flow direction of the photocurrent through the capacitor at twice the clock frequency. At the end of the integration period, the capacitor provides a differential photocharge, corresponding to a capacitor voltage. The capacitor voltage is related to the time of flight of the light pulses and may be used to determine a distance to a target.

Abstract: A system and method are provided that allow for direct measurement of relative movement and relative velocity of movement of a crane (10) boom tip (14) in relation to a target load (24) on an adjacent vessel deck (20) allowing real-time determination of work load parameters under then-current conditions. A rangefinder (32) is located proximate boom tip (14) without requirement of a device on the target load or load vessel. A method accumulates relative movement, environmental data and as-built crane design to determine rated capacity of crane (10).

Abstract: A light transit time camera system and method for operating such a system which can be operated with at least three modulation frequencies, having the steps a) determining a phase shift (?i) of an emitted signal (Sp1) and a received signal (Sp2) for a modulation frequency (f1, f2, f3) in a phase-measuring cycle (PM1, PM2, . . . ), b) carrying out a plurality of phase-measuring cycles (PM1, PM2, . . . ), c) determining a distance value (dn,n+1) on the basis of the phase shifts (?n, ?n+1) determined in two successive phase-measuring cycles (PMn, PMn+1), in a distance-measuring cycle (M1, M2, . . . ), d) carrying out a plurality of distance-measuring cycles (M1, M2, . . . ), e) determining a distance deviation (?d) between the distance values of successive distance-measuring cycles, f) outputting of a distance value (dn,n+1) as a valid distance value if the distance deviation (?d) is within a tolerance limit (?dtol) is provided.

Abstract: A distance detecting induction device includes a casing, a circuit board within the casing, and a pair of focusing lenses provided at respective openings in the casing. The distance detecting induction device further includes an emitting device including an infrared light emitting diode for emitting infrared light rays to the emitting lens and a receiving device including a distance detection induction module for inducing reflected light rays focused by the receiving lens. The distance detecting induction device further includes an emitting light ray guiding device arranged between the emitting lens and the emitting device. The guiding device includes a small circular hole provided at a position of the emitting device and a big circular hole provided at a position of the emitting lens.

Abstract: A light scanning apparatus including a light source for emitting light in a direction different from a direction orthogonal to the reference direction, and a rotating reflection body that rotates about an axis inclined at an inclination angle ? to the reference direction and includes at least one reflecting surface that is disposed in a direction intersecting obliquely with the axis and reflects light incident on the reflecting surface at an incident angle ?. A specific scanning direction is a direction intersecting at an angle to the reference direction and the rotation axis inclination angle ??0°. The inclination angle ? is predetermined according to the incident angle ? such that deviation of the scanning beam reflected by the reflecting surface is smaller than the deviation of the scanning beam that would be obtained with the inclination angle ? of the rotation axis 0°.

Abstract: A laser radar device includes: a pulse laser that outputs transmission light to a target; an transmission optical system that makes the transmission light at a predetermined beam spread angle; a light-receiving element array that receives scattered light from the target and converts the light to an electric signal; an electric circuit array that detects a reception intensity and a reception time from the electric signal; a range/three-dimensional shape output unit that measures a range to the target or a three-dimensional shape of the target on the basis of the reception time; a determination unit that determines whether the beam spread angle is changed or not on the basis of the reception intensity and the reception time; and a control unit that changes the beam spread angle on the basis of a determination result.

Abstract: A LiDAR system and method are disclosed, comprising a housing, a light source, a receiver, and a light deflection system comprising a light deflection element, rotatable and balanced about an axis, the element having at least three sides, at least two of the three sides having reflective surfaces, wherein at least a first side of the three sides is at a first angle in relation to the axis, and at least a second side of the three sides is at a second angle in relation to the axis, with the first angle being different from the second angle, such that light is deflectable from the reflective surface of the first and second sides out of the housing, whereby upon actuation of the light source and rotation of the light deflection element, the LiDAR system forms at least a first scan path and a second scan path.

Abstract: An optical sensor includes a driver, light detector and echo canceller. The driver is adapted to selectively drive a light source. The light detector is adapted to produce a detection signal indicative of an intensity of light detected by the light detector. The echo canceller is adapted to produce an echo cancellation signal that is combined with the detection signal produced by the light detector to produce an echo cancelled detection signal having a predetermined target magnitude (e.g., zero). The echo canceller includes a coefficient generator that is adapted to produce echo cancellation coefficients indicative of distance(s) to one or more objects, if any, within the sense region of the optical sensor. The optical sensor can also include a proximity detector adapted to detect distance(s) to one or more objects within the sense region of the optical sensor based on the echo cancellation coefficients generated by the coefficient generator.

Abstract: A laser radar device mounted on a vehicle includes a first laser emission part configured to generate a measuring laser beam by using a laser beam emitted from a laser source and to illuminate a predetermined area in a front traveling direction and a second laser emission part configured to generate a measuring laser beam by using the laser beam emitted from the laser source. A beam spread angle, viewed from a side of the vehicle, of the measuring laser beam generated by the second laser emission part is larger than a beam spread angle, viewed from a side of the vehicle, of the measuring laser beam generated by the first laser emission part.

Abstract: A method and a device for determining the orientation of at least one rail of a measuring station of a chassis measuring device or a motor vehicle test line. The device has at least one sensing device, the at least one sensing device has at least one camera and at least one illumination unit. The at least one illumination unit illuminates at least one section of the rail using structured or unstructured light and the at least one camera records the light reflected by the rail.

Abstract: Using a hand-held range finding device to range an object in a field of view is difficult due to user-induced jitter. In particular, user-induced jitter introduces uncertainty as to which object in a field of view is actually ranged. Current approaches attempt to mitigate user-induced jitter by requiring a user to mount the hand-held range finding device onto a stabilizing device (e.g., a tripod). However, such approaches require the user to carry additional equipment. Embodiments of the present disclosure enable the user to visually confirm which object in a field of view is actually ranged during a range finding event by generating a composite image that includes a visual representation of a laser pulse emitted by the range finding device reflecting off an object in the field of view. Advantageously, disclosed embodiments provide true hand-held range finding capabilities without requiring the use of stabilization assistance techniques.

Abstract: Phase-based TOF systems operate with reduced depth error due to motion blur, and/or spatial blur, and/or pixel offset by intelligently determining how best to combine pixel values, and how best to compensate for individual pixel offsets. Such determination(s) may be carried out on a per pixel basis, dynamically, in real-time during TOF operation, or on archived TOF data. Offsets for individual pixels may be dynamically calculated and subtracted from the values acquired by those pixels Individual pixel offsets may be calculated for example by combining data acquired by the same pixel at two acquisitions, 180° out of phase with respect to each other. Calculated offsets may be averaged, or on a per pixel basis, and if target object motion is detected, one or more offset calculations can be discarded rather than averaged to reduce motion blur. Offsets acquired a priori during a TOF system calibration procedure may be used.

Abstract: Disclosed is a distance measuring device configured to irradiate an object with light and receive reflected light therefrom to measure a distance from the object, including a light source device having at least one light-emitting part, a deflection part being provided rotatably around a predetermined axis line and having plural deflection faces configured to reflect light from the light source device toward the object, a reflection part being provided rotatably around the axis line and integrally with the deflection part and having plural reflection faces being provided to correspond to the plural deflection faces individually and reflecting a portion of light reflected from a corresponding deflection face and reflected from the object, and a light-receiving part having at least one light-receiving element configured to receive light reflected from the reflection part, wherein respective inclination angles of the plural deflection faces with respect to the axis line are mutually different.

Abstract: In some embodiments, distances associated with a surface may be calculated using time-of-flight (ToF) of a plurality of pulses of light occurring at a predetermined frequency. Reflected light from a light emitter may be captured by two or more light sensors. At least one light sensor may be located in a sensor pod that is separate from the light emitter, which may be housed in an emitter pod with or without a light sensor. The sensor pod may be synchronized with the emitter pod to enable ToF of light distance calculations. The calculated distance may be used to determine movement of a surface and/or one or more pixels of a surface. In some instances, the calculated distance may be used to identify a profile of a surface, which may then be used associate the profile with an object, a command, or another association.

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: Methods and apparatus are provided for measuring distance from an instrument origin to each of a plurality of points in an environment. Laser pulses are emitted along a measurement axis at successive displacements about the origin. The emission time of each pulse is time-shifted relative to a fixed rate. The time shift corresponds to an index of a repetitive sequential pattern. Received pulses are detected at respective arrival times. For each received pulse: a current apparent distance is determined, a measured delta distance is calculated, a range interval is assigned by comparing measured delta distance with an expected delta distance synchronized with the index of the latest emitted pulse, the current apparent distance is defined to be a true measured distance for any received pulse assigned to a first time interval, otherwise the current apparent distance is defined to be a false measured distance.

Abstract: A system for landing or docking a mobile platform is enabled by a flash LADAR sensor having an adaptive controller with Automatic Gain Control (AGC). Range gating in the LADAR sensor penetrates through diffuse reflectors. The LADAR sensor adapted for landing/approach comprises a system controller, pulsed laser transmitter, transmit optics, receive optics, a focal plane array of detectors, a readout integrated circuit, camera support electronics and image processor, an image analysis and bias calculation processor, and a detector array bias control circuit. The system is capable of developing a complete 3-D scene from a single point of view.

Abstract: An optoelectric control apparatus for a satellite laser ranging system comprises a communication controller for externally receiving optoelectric control data. Memory is connected to the communication controller and stores a round trip distance to a satellite. A laser generation control unit is connected to the communication controller and outputs a laser fire signal. A signal measurement unit receives a laser start time. A real-time conversion unit is connected to the signal measurement unit and the communication controller, and converts a predicted laser arrival time into real time. A Lagrange interpolation processor is connected to the real-time conversion unit and the memory, and calculates a time at which laser light fired by a laser transmission unit returns back to a laser reception unit (laser arrival time). The clock unit is connected to a time measurement unit, the real-time conversion unit, a register unit, and a delay unit, and outputs time information.

Abstract: A system for determining the speed and position of objects comprises a beam source, a transmit reflection device, a beam receiver, a receive reflection device, and a controller. The beam source may generate a beam. The transmit reflection device may reflect the beam at the objects and may include a plurality of transmit faces with each transmit face oriented at a different angle and operable to reflect the beam at a different height. The beam receiver may detect the beam. The receive reflection device may include a plurality of receive faces with each receive face oriented at a different angle and operable to focus the beam reflected from objects at different heights onto the beam receiver. The controller may determine the position of the objects over time and calculate the speed of the objects based on a change in the position of the objects.

Abstract: The invention relates to a portable observation device having an observation path for optical targeting of a target object, and comprising an optoelectronic rangefinder for measuring the distance in the direction of the targeting. The rangefinder includes a transmission unit for emitting a temporal sequence of pulses of optical radiation, a reception unit for receiving a portion of the optical radiation cast back by the target object and for determining signal information and an electronic evaluation unit, which a distance to the target object can be determined on the basis of a signal travel time between emission and reception of the optical radiation. When a trigger is actuated manually, the distance is determined including the signal information from a specified minimum number of pulses, which define a minimum length of a time window of the distance measurement.

Abstract: Disclosed herein is an illumination system including an array of LED light sources for emitting light encoded with a modulation pattern, an array of sensors and a space characterization unit. The array of sensors receives emitted light scattered by an object. Each sensor determines a distance between the corresponding light source and the object using the modulation pattern. The space characterization unit uses the distance from each sensor to generate an elevation map indicating a presence of the object.

Abstract: A method for computing a depth map of a scene in a structured light imaging system including a time-of-flight (TOF) sensor and a projector is provided that includes capturing a plurality of high frequency phase-shifted structured light images of the scene using a camera in the structured light imaging system, generating, concurrently with the capturing of the plurality of high frequency phase-shifted structured light images, a time-of-flight (TOF) depth image of the scene using the TOF sensor, and computing the depth map from the plurality of high frequency phase-shifted structured light images wherein the TOF depth image is used for phase unwrapping.

Abstract: A fast spatial light modulator based on a linear MEMS ribbon array enables a depth capture system to operate in structured light and time-of-flight modes. Time-of-flight depth information may be used to phase unwrap structured light depth information. Combined structured light and time-of-flight systems offer precise depth resolution over a wide range of distances.

Abstract: A rangefinder for measuring a distance of an object includes a case, in which a refractor, a measuring light source, a light receiver, a receiving lens, a reference light source, and a reflector are provided. The measuring light source emits measuring light to the refractor, and the refractor refracts the measuring light to the object. The measuring light reflected by the object emits to the light receiver through the receiving lens. The reference light emits reference light to the reflector, and the reflector reflects the reference light to the light receiver. The refractor and the reflector may be turned for calibration.

Abstract: A detection system for detecting an object includes a transmitter including a light source configured to emit a first light beam having a first frequency towards the object. The detection system also includes a receiver configured to receive a second light beam reflected from the object, and a detector positioned within the receiver. The second light beam has a second frequency as a result of a non-linear optical response of a surface of the object to the first light beam. The detector is configured to detect the object based on the second frequency of the second light beam.

Abstract: The invention relates to the topographic technique field, and provides a ranging method and a system, wherein the ranging method comprises the following steps: modulating measured beam, by a modulated signal of which the frequency is continuously changed over time; emitting the modulated measured beam to a measured object; receiving the reflected measured beam and converting the beam into the measured signals; and comparing the frequency of the modulated signal generated when the measured beam is received with the frequency of the measured signals, thus determining the measured distance.

Abstract: Systems and methods presented herein provide for laser detection and ranging in more than one medium. In one embodiment, a laser is operable to generate and fire laser pulses into a liquid, such as water. The laser pulses form broadband super continuum emissions and/or harmonics in the liquid that propagate optical energy past a surface of the liquid. A detector is operable to receive the optical energy from the liquid, which is then processed to determine a range parameter of the liquid. That is, a processor may determine the depth of the water or an object beneath the surface of the water by measuring the travel times of optical energy reflected from the surface of the liquid and optical energy returned from beneath the surface of the liquid.

Abstract: An optical system includes a transmitter emitting a signal to a measured object; a receiver receiving the signal reflected back from the measured object; and a transmissive display device displaying a distance of the measured object measured by the range finder, wherein an image of the measured object is visible directly through the transmissive display device.

Abstract: A method and apparatus for enhancing the resolution of three-dimensional imagery data are disclosed. The method includes registering a frame of the three-dimensional imagery data with a template frame; and temporally averaging the registered frame with the template frame. The apparatus includes a program storage medium encoded with instructions that, when executed by a computing apparatus, performs the method and an apparatus programmed to perform the method.

Abstract: Separate reception/transmission apertures enhance pointing: reception is more efficient than transmission (kept smaller for MEMS steering). Apparatus aspects of the invention include lidar transmitters emitting laser beams, and scan mirrors (or assemblies) angularly adjustable to deflect the beams in orthogonal directions. In one aspect, afocal optics magnify deflection; a transmitter aperture transmits the beam; a lidar receiver doesn't share the transmitter aperture. In another aspect, auxiliary optics calibrate the deflection. A method aspect of the invention notices and responds to a remote source—using a similar local laser, adjustable scan mirror or assembly, afocal deflection magnifier, transmission aperture and separate receiver. Method steps include operating the receiver to notice and determine location of the remote source; and controlling the transmitter to direct laser light back toward that location.

Abstract: A triangulation light sensor includes at least one light transmitter for transmitting a light signal into a detection zone, a light receiver having a plurality of receiver elements for receiving light from the detection zone reflected diffusely and/or specularly, and a reception optics arranged between the detection zone and the light receiver in the beam path, with the position of a light spot produced on the light receiver in a triangulation direction by the reflected light resulting in dependence on the distance of the object. The reception optics includes at least one multisegmented lens element having a plurality of lens segments with mutually spaced apart optical axes in the triangulation direction and at least one freeform lens element or one diffractive-optical element having a multisegmented lens element having a plurality of lens segments with optical axes spaced apart from one another in the triangulation direction.

Abstract: A CMOS detector with pairs of interdigitated elongated finger-like collection gates includes p+ implanted regions that create charge barrier regions that can intentionally be overcome. These regions steer charge to a desired collection gate pair for collection. The p+ implanted regions may be formed before and/or after formation of the collection gates. These regions form charge barrier regions when an associated collection gate is biased low. The barriers are overcome when an associated collection gate is high. These barrier regions steer substantially all charge to collection gates that are biased high, enhancing modulation contrast. Advantageously, the resultant structure has reduced power requirements in that inter-gate capacitance is reduced in that inter-gate spacing can be increased over prior art gate spacing and lower swing voltages may be used. Also higher modulation contrast is achieved in that the charge collection area of the low gate(s) is significantly reduced.

Abstract: According to at least one example embodiment, a depth information error compensation method includes outputting modulated light to a target object, detecting a plurality of first pixel signals at different detection time points in a first time interval, the first pixel signals representing light reflected from the target object during the first time interval, detecting a plurality of second pixel signals at different detection time points in a second time interval, the second pixel signals representing light reflected from the target object during the second time interval, comparing each of the plurality of first pixel signals with each of the plurality of second pixel signals and calculating depth information to the target object according to the comparing.

Abstract: The invention relates to a binocular observation device, in particular binoculars, having two visual beam paths and a laser range finder with a laser transmitter and a laser receiver and with an opto-electronic display element. A part of one of the beam paths of the laser transmitter is integrated into a first visual beam path, wherein a part of one beam path of the laser receiver is furthermore also integrated into the first visual beam path.

Abstract: TOF system optical power is augmented using auxiliary optical emitter unit(s) that may be a wireless (WOE), or a plug-wired (PWOE). WOE units sense emitted TOF system optical energy Sout and emit optical energy Sout-n preferably dynamically synchronized in frequency and in phase to Sout as received by the WOE. Each WOE includes at least one optical sensor to detect Sout, and internal feedback ensuring that frequency and phase of the WOE emitted Sout-n optical energy are dynamically synchronized with frequency and phase of the TOF emitted Sout optical energy. PWOE units need no internal feedback but are calibrated by the TOF system to cause a close match between frequency and phase of the PWOE-emitted optical energy with what would be emitted by the TOF system primary optical source. If PWOE(s) are used in isolation, delay difference between PWOE and the TOF primary optical energy source can be software-compensated.

Abstract: A first photoelectric conversion element, which detects light and converts the light into photoelectrons has: one MOS diode having an electrode formed on a semiconductor base body with an insulator therebetween; and a plurality of embedded photodiodes formed in the semiconductor base body. The electrode of the MOS diode has, when viewed from the upper surface, a comb-like shape wherein a plurality of branch portions are branched from one electrode portion. Each of the embedded photodiodes is disposed to nest between the branch portions of the electrode when viewed from the upper surface.

Abstract: In one aspect, a method includes forming range bins from range compressed data, the range compressed data comprising a train of coherent pulses formed based on a transmitted signal from a laser detection and ranging (LADAR) sensor and having a large time-bandwidth product and for each range bin, compensating for motion of the LADAR sensor, performing a Fourier transform on the compressed range data, determining a centroid of individual velocity measurements and performing Fourier transform of the centroid to determine a vibration.

Abstract: A first photoelectric conversion element for detecting light and converting the light into photoelectrons comprises one buried photodiode formed in a semiconductor substrate, and a plurality of MOS diodes each having an electrode formed on the semiconductor substrate with an insulator interposed therebetween. The buried photodiode has a comb shape, in which a plurality of diverging portions are disposed to diverge from one portion, when viewed from the top thereof, and the respective electrodes of the MOS diodes are disposed so as to be nested between the plurality of diverging portions of the buried photodiode when viewed from the tops thereof.

Abstract: A laser scanning device includes a light source and a light scanner that scans a laser light emitted from the laser light source. The light source emits the laser light so that the laser light is incident to the light scanner from a plurality of directions.

Abstract: A sensor, including a plurality of photo gate pairs on a semiconductor substrate, each of the photo gate pairs including a first photo gate and a second photo gate, a first shared floating diffusion region in the semiconductor substrate, and a plurality of first transmission transistors on the semiconductor substrate, wherein each of the plurality of first transmission transistors is adapted to transmit charges to the first shared floating diffusion region in response to a first transmission control signal, the charges being generated in the semiconductor substrate under the first photo gate of each of the plurality of photo gate pairs.

Abstract: An optoelectronic sensor (10) for distance determination comprises a transmitter (12) for transmitting a light beam (14) having a plurality of consecutive individual light pulses, a rotatable deflection unit (16) for deflecting the light beam (14), an angle measuring unit (28) for determining an angular position of the deflection unit (16), a light receiver (24) for generating reception pulses from remitted transmission light, a plurality of histogram memories (34) each associated with an angular position, and an evaluation unit (30) which is configured to accumulate time histograms in the histogram memodes (34) across several periods of the rotational movement of the deflection unit (16) from reception pulses which are each detected at the angular position associated with the respective histogram memory (34), and to determine, from the histograms of the associated histogram memory (34), an object distance for an angular position.

Abstract: Techniques are disclosed for providing a multi-zone sensing array configured for use in a dual-mode active/passive sensor system. In some embodiments, the techniques can be used to minimize or otherwise reduce power dissipation in sensor arrays, while further providing the ability to readout the active returns rapidly. The techniques can be implemented, for example, by using the full N×M array format for target acquisition in a passive imaging mode, and then, with the aid of a gimbal for instance, place the region-of-interest in a subset of the array configured with dual-mode active/passive pixel receivers to provide three-dimensional imaging. Such techniques are capable of, for example, supporting both active and passive operating modes of a countermeasure system.

Abstract: A system for providing a sliced optical pulse is disclosed. The system can comprise a master oscillator (MO) configured to generate an optical pulse at a first spectral bandwidth. The system can also comprise a semiconductor optical amplifier (SOA) configured to slice the optical pulse to generate a sliced optical pulse that has a second spectral bandwidth. The second spectral bandwidth can be smaller than the first spectral bandwidth.

Abstract: A detection apparatus and method for FMCW LIDAR employ signals whose frequencies are modified so that low-cost and low-speed photodetector arrays can be employed for range detection. The LIDAR includes a single mode swept frequency laser (SFL), whose optical frequency is varied with time, as a result of which, a target beam reflected back by the target is shifted in frequency from a reference beam by an amount that is proportional to the relative range z to the target. The reflected target beam is combined with the reference beam and detected by the photodetector array. The difference between the frequencies of the reflected target beam and the reference beam is reduced to a level that is within the bandwidth of the photodetector array by first modulating the target and/or reference beam.

Abstract: A portable hand held tank gauge for measuring a level or a volume of a fluid in a tank comprises a housing, a signal transceiver, a measurement activator, an adjustable arm, a processing element, and a display. The housing may house a portion of the other components. The signal transceiver may transmit a signal to the surface of the fluid, receive the signal reflected from the surface, and generate an output based on the difference in time between transmitting the signal and receiving the signal. The measurement activator may selectively initiate the signal transceiver to transmit the signal. The adjustable arm may couple to the housing and position the signal transceiver independently from the housing. The processing element may calculate the level or the volume of the fluid based on the output from the signal transceiver. The display may display the level or the volume of the fluid.

Abstract: The invention describes an electronic travel aid (ETA) for blind and visually impaired persons implemented in a detachable handle of a white cane. The device enhances the functionality of the white cane giving the user more detailed information about the environment within a defined corridor of interest in front of the user with an extended range of a few meters up to 10 m. It provides a reliable warning if there is a risk of collision with obstacles including those at trunk or head height, which are not recognized by a conventional white cane. Additional sensors are integrated to delimit the defined corridor during the cane sweeping thereby reducing the amount of information that is transmitted to the user via the tactile interface. Alternatively, the device can be used independently from the cane as an object recognition and orientation aid.