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: In the conventional contaminant particle/defect inspection method, if the illuminance of the illumination beam is held at not more than a predetermined upper limit value not to give thermal damage to the sample, the detection sensitivity and the inspection speed being in the tradeoff relation with each other, it is very difficult to improve one of the detection sensitivity and the inspection speed without sacrificing the other or improve both at the same time. The invention provides an improved optical inspection method and an improved optical inspection apparatus, in which a pulse laser is used as a light source, and a laser beam flux is split into a plurality of laser beam fluxes which are given different time delay to form a plurality of illumination spots. The scattered light signal from each illumination spot is isolated and detected by using a light emission start timing signal for each illumination spot.

Abstract: The invention relates to an optical measuring device (1) having a housing (3), in which at least one optical emitter (20) for emitting at least one emission beam (22, 24) and at least one optical receiver are arranged, wherein a cover disc (5) terminates the housing and forms an emission window (10) and a reception window (7), wherein the at least one emission beam (22, 24) exits from the housing through the emission window (10), wherein the receiver receives the emission beam, which is reflected from the surroundings, as a reception beam through the reception window (7), and wherein the cover disc (5) has a heating assembly (20), and a corresponding method for producing a cover disc (5) for the optical measuring device (1).

Abstract: An Integrated Laser Field Conjugation System (ILFCS) for end-to-end compensation of high-energy laser for propagation through turbulence with non-cooperative target. ILFCS using interferometric slaving technique and stand-alone adaptive optical systems to effect pre-compensation of amplitude and phase aberrations in turbulent medium, providing pre-compensation for aberrations in a laser amplifier. Performing compensation functions in low-power beam paths, increasing capability, reducing cost, reducing size compensation components for phase correction devices. Pre-compensating low-power master oscillator beam for aberrations in both high-power amplifier and turbulent propagation path-to-target with configuration enabling wavefront sensing of aberrations. Can be configured to perform phase compensation, or compensation of phase/amplitude aberrations. Capability to compensate aberrations in master oscillator beam.

Abstract: A lightweight, low volume, inexpensive LADAR sensor incorporating 3-D focal plane arrays is adapted specifically for personal electronic appliances. The present invention generates, at high speed, 3-D image maps and object data at short to medium ranges. The techniques and structures described may be used to extend the range of long range systems as well, though the focus is on compact, short to medium range ladar sensors suitable for use in personal electronic devices. 3-D focal plane arrays are used in a variety of physical configurations to provide useful new capabilities to a variety of personal electronic appliances.

Abstract: Methods and devices for the determination of distance by means of light pulses are disclosed. A light source emits light pulses with specified frequency. A detector receives reflected light pulses. A controller controls the light source and detector by means of signals. At least two timers are connected to the controller and the detector. When a light pulse is emitted by the light source, the controller generates a start signal triggering a time measurement by each of the at least two timers, in order, and beginning again from the start. Upon receiving a reflected light pulse, the detector generates a stop signal which stops the time measurement by the timer of the at least two timers, to which at that instant a measuring window is assigned by the controller. The device can be designed as a fiber-optic scanner.

Abstract: A distance measuring system and a distance measuring method which use a time-of-flight (TOF) method. The distance measuring system obtains a reference light quantity of reflected light which is a cumulative light quantity of the reflected light during a reference period, obtains a measured light quantity of the reflected light which is a cumulative light quantity of the reflected light during a measurement period, and calculates, on the basis of a ratio of the measured light quantity of the reflected light to the reference light quantity of the reflected light and a ratio of the reflected light incident period to the reference period, a reflected light incident period that is a period which is included in the measurement period and during which the reflected light is incident upon photoelectric conversion elements of a light-receiving device. Then, the distance measuring system calculates the distance between the distance measuring system and an object on the basis of the reflected light incident period.

Abstract: An object characteristic measuring system, used to measure semiconductor thin film characteristics, is formed by a dual-optical comb absolute distance measuring device and a terahertz (THz) wave time-domain measuring device. The dual-optical comb absolute distance measuring device is formed by two laser modules, for determining a first characteristic of an object to be measured through laser pulses emitted by the two laser modules. The THz wave time-domain measuring device is used to emit a THz wave, so as to measure a second characteristic of the object to be measured.

Abstract: Methods and devices for the determination of distance by means of light pulses are disclosed. A light source emits light pulses with specified frequency. A detector receives reflected light pulses. A controller controls the light source and detector by means of signals. At least two timers are connected to the controller and the detector. When a light pulse is emitted by the light source, the controller generates a start signal triggering a time measurement by each of the at least two timers, in order, and beginning again from the start. Upon receiving a reflected light pulse, the detector generates a stop signal which stops the time measurement by the timer of the at least two timers, to which at that instant a measuring window is assigned by the controller. The device can be designed as a fiber-optic scanner.

Abstract: The present invention determines the dimensions and volume of an object by using a novel 3-D camera that measures the distance to every reflective point in its field of view with a single pulse of light. The distance is computed by the time of flight of the pulse to each camera pixel. The accuracy of the measurement is augmented by capture of the laser pulse shape in each camera pixel. The camera can be used on an assembly line to develop quality control data for manufactured objects or on a moving or stationary system that weighs as well as dimensions the objects. The device can also ascertain the minimum size of a box required to enclose an object.

Abstract: The invention relates to an optical-electronic distance measuring method according to the phase measurement principle by emitting of optical measuring radiation, which is modulated according to the burst modulation principle, having a burst period duration made of an active burst time and a dead time, receiving at least a part of the measuring radiation (23), which is reflected on the measured object, wherein transforming into an input measuring signal (ES) is performed, and determining a distance to the measured object by analyzing a measuring signal (MS, gMS) generated from the input measuring signal (ES).

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: 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: A device (1) for the determination of distance by means of light pulses is disclosed. The device (1) comprises a light source (2) for emitting light pulses with a specified frequency, a detector (8) for receiving the light pulses emitted and reflected by the light source, and a controller (4) which is in communication with the light source (2) and the detector (8) and which can control said light source and detector by means of signals. The device (1) further comprises at least two timers (Z1, Z2, Z3) which are connected to the controller (4) and the detector (8). Said controller (4) is designed in such a way that when a light pulse is emitted by the light source (2), the controller (4) generates a start signal which triggers the time measurement by each one of the at least two timers, in order, and beginning again from the start.

Abstract: A method is provided for generating measurement parameters for a particle sample in a particle analyzer. The method includes, interrogating the particle sample with a triggering interrogator and one or more secondary interrogators respectively positioned along a length of an interrogation area, generating respective pulses based upon the interrogation of a first particle from the particle sample, determining a primary pulse detection window based upon a triggering pulse, determining a search interval to find a secondary pulse based upon factors including the primary pulse detection window and a laser delay, adjusting the search interval for laser delay variation dynamically based on the interrogation of the first particle, identifying the secondary pulse in the adjusted search interval, and processing the secondary pulse to determine a peak value of the secondary pulse. Corresponding apparatus are also provided.

Abstract: A distance measuring system and a distance measuring method which use a time-of-flight (TOF) method. The distance measuring system obtains a reference light quantity of reflected light which is a cumulative light quantity of the reflected light during a reference period, obtains a measured light quantity of the reflected light which is a cumulative light quantity of the reflected light during a measurement period, and calculates, on the basis of a ratio of the measured light quantity of the reflected light to the reference light quantity of the reflected light and a ratio of the reflected light incident period to the reference period, a reflected light incident period that is a period which is included in the measurement period and during which the reflected light is incident upon photoelectric conversion elements of a light-receiving device. Then, the distance measuring system calculates the distance between the distance measuring system and an object on the basis of the reflected light incident period.

Abstract: An apparatus for measuring distance to a surface is disclosed. The apparatus transmits at least one subsequent pulse of light prior to receiving a reflection of a previously sent pulse of light. Thus, multiple pulses of light are in-flight at a given time. The embodiments are applicable to terrain mapping, bathymetry, seismology, detecting faults, biomass measurement, wind speed measurement, temperature calculation, traffic speed measurement, military target identification, surface to air rangefinding, high definition survey, close range photogrammetry, atmospheric composition, meteorology, distance measurement, as well as many other applications. Examples of such apparatuses include laser ranging systems, such as light detection and ranging (LIDAR) systems, and laser scanners. Data received from the apparatus by a data processing unit can be used to create a data model, such as a point cloud, digital surface model or digital terrain model describing the surface, terrain, and/or objects.

Abstract: A computationless system is provided for determining the direction of and distance to a target, involving bathing an area surrounding an area to be protected with a polyspectral series of narrow fan beams of different colors from at least two spaced-apart projectors. The differently colored beams go out at different angles, thus to color-code map the area surrounding the protected space where beams of different colors cross to form color-coded cells. Light reflected back to the area to be protected from a threat has a color code corresponding to the colors associated with beams that cross at the threat, thus to identify by the reflected colors where in space the threat is located.

Abstract: An optical-member driving apparatus for laser radar, comprising: an optical-member integrated portion including an optical member and an optical-member mounted portion having the optical member mounted thereon; first erection members supporting the optical-member integrated portion; a relay portion to which the first erection members is connected; second erection members supporting the relay portion; and a fixed portion to which the second erection members are connected.

Abstract: An imaging system has a transmission system (2) for transmitting a modulated optical signal and a reception system (3) for receiving a received optical signal which is a reflected and delayed version of the transmitted signal. The reception system includes a controllable shutter arrangement for allowing reception in a controllable time window. A memory (4) collects reception data derived from different time windows, and a measure of distance is obtained corresponding to a maximum correlation between the received optical signal and the timing of the controllable time window. Surface profile information is derived from multiple distance measurements. The shutter arrangement enables the distance measurement (and the subsequent profile calculation) to be free from noise from other scattering sources.

Abstract: A distance measuring method for detecting the spatial dimension of at least one target by at least one emission of a multiplicity of light pulses, in particular laser light, towards the target, detecting the light pulse scattered back by the target by means of a multiplicity of distance measuring pixels and eliminating the distance to the target for each pixel, wherein each light pulse can be detected within a measuring interval Ti from at least two partial intervals tij and the detection of at least one repetition constitutes a detection step performed in at least two stages wherein the measuring interval T˜ is shortened from stage to stage.

Abstract: The invention relates to a device for determining the distance of an object in local resolution mode, using a frequency-shifted feedback radiation source for irradiating the object with radiation that can be used to determine distance and using a position-sensitive object recording sensor. According to the invention, the frequency-shifted feedback laser for irradiating the object is equipped with an element for increasing the beat intensity of the emission frequency component and the position-sensitive object recording sensor is configured to record the beat intensity of the object and not the incoming radiation from the object.

Abstract: The invention relates to a method for measuring distance wherein pulsed electromagnetic radiation is emitted by at least one transmitter and the reflected signal impulses are detected by at least one receiver. According to the invention, the distances of the objects, at which the emitted radiation impulses are reflected, is measured by determining the propagation time of the impulses. The noise is measured by a receiver and moments in time during which a noise threshold of the receiver is exceeded, are determined, and modifications of the noise produced by the signal impulses are detected by the communicating of a plurality of individual measurements respectively comprising said moments in time.

Abstract: A recording device for distance images becomes multi-target-enabled by means of the arrival of light pulses reflected at object regions at different distances being temporally resolved. This is done using extrema of the gradient of a correlation function between the received light pulses and a time window during which sensor elements of a camera are activated.

Abstract: An imaging system. Implementations of imaging systems may include a laser light source, at least one imaging detector coupled to the laser light source, a shearing interferometer coupled to at least one imaging detector, and a timing system coupled to the at least one imaging detector and the laser light source. A ranging detector may be coupled to the laser light source and the timing system, and at least on sensitivity modulator may be coupled with the at least one imaging detector and with the timing system.

Abstract: A system and method for the taking of a large number of distance images having distance picture elements. Electromagnetic radiation is transmitted in the form of transmission pulses at objects, and reflected echo pulses are detected. Measurements are made by determining the pulse time of flight of the distances of objects which respectively form a distance picture element and at which the transmission pulses are reflected. A time measuring device carries out a plurality of associated individual measurements for each distance image to be taken. Stored event lists of all time measuring channels are read out and evaluated in order to convert the respective time information contained in the event lists into distance values corresponding to the distance picture elements.

Abstract: A vehicle mounted imaging system and method, enabling selective imaging of objects in a low-visibility environment. The system includes a light source providing non-visible light pulses and a camera having an image intensifier enabled to gate selected received images. The light source may be a laser generator, which may be enabled to generate a pulse width related to the depth of a field to be imaged. The gated image intensifier may determine gating time spans according to the depth of a field to be imaged.

Abstract: The invention relates to a frequency-shifted feedback radiation source, equipped with an element for increasing the beat intensity of the emission frequency component.

Abstract: A device (1) for the determination of distance by means of light pulses is disclosed. The device (1) comprises a light source (2) for emitting light pulses with a specified frequency, a detector (8) for receiving the light pulses emitted and reflected by the light source, and a controller (4) which is in communication with the light source (2) and the detector (8) and which can control said light source and detector by means of signals. The device (1) further comprises at least two timers (Z1, Z2, Z3) which are connected to the controller (4) and the detector (8). Said controller (4) is designed in such a way that when a light pulse is emitted by the light source (2), the controller (4) generates a start signal which triggers the time measurement by each one of the at least two timers, in order, and beginning again from the start.

Abstract: Ladar systems and methods are provided. One embodiment is a ladar system comprising: a chirp generator for generating a chirped waveform; a laser for transmitting a light signal toward a target, the light signal being modulated by the chirped waveform; and a photon-counting sensor for receiving a temporally-modulated photon stream corresponding to the modulated light signal being reflected from the target and toward the ladar system, the photon-counting sensor gated relative to the chirped waveform.

Abstract: A range-gated shearography system and related methods. Implementations of range-gated shearography systems may include a laser light source, at least one imaging detector coupled to the laser light source, a shearing interferometer coupled to the at least one imaging detector, and a ranging detector coupled to the laser light source. A method of range-gating a shearography system may include emitting laser light, determining a range interval for at least one object, receiving reflected laser light from the at least one object through a shearing interferometer from the range interval, and collecting at least one shearography image.

Abstract: Land-based vehicle including an arrangement for monitoring objects in or about a vehicle which includes a source from which illumination is emitted into an area in or about the vehicle, a receiver arranged to receive illumination reflected from an object in the path of the illumination, a light-regulating component arranged in front of the receiver to regulate reception of illumination by the receiver, and circuitry coupled to the source, the receiver and the light-regulating component. The light-regulating component is modulated to enable a determination of a distance between an object from which the illumination has been reflected and the receiver. The circuitry obtains information about objects from which the received illumination has been reflected other than distance information and associates with the objects distances between the objects and the receiver. This improves the ability to control vehicular systems based on the presence of objects in or about the vehicle.

Abstract: A rangefinding device and a method for determining the range of an object from a rangefinding device are provided. A train of light pulses each having an emission time and a pulse duration is generated. The pulse duration is set to twice the round-trip time to a maximum range of the device. The light pulses are reflected back toward the device by the object and detected according to three time intervals, respectively determined by a background gate, a ranging gate and a pulse energy gate. The light energy received during each interval is integrated and the integrated light value corresponding to the ranging gate is normalized using the values from the other two intervals. The range of the object is determined from the normalized ranging measurement and calibration data.

Abstract: A recording device for distance images becomes multi-target-enabled by means of the arrival of light pulses reflected at object regions at different distances being temporally resolved. This is done using extrema of the gradient of a correlation function between the received light pulses and a time window during which sensor elements of a camera are activated.

Abstract: An imaging system has a transmission system (2) for transmitting a modulated optical signal and a reception system (3) for receiving a received optical signal which is a reflected and delayed version of the transmitted signal. The reception system includes a controllable shutter arrangement for allowing reception in a controllable time window. A memory (4) collects reception data derived from different time windows, and a measure of distance is obtained corresponding to a maximum correlation between the received optical signal and the timing of the controllable time window. Surface profile information is derived from multiple distance measurements. The shutter arrangement enables the distance measurement (and the subsequent profile calculation) to be free from noise from other scattering sources.

Abstract: Technology is disclosed for measuring distances. A measurement device emits a beam that reflects on the surface of an object. The measurement device determines the distance to the object, based on the time of flight of the beam from transmission to capture by the measurement device. The device includes a light source adapted to provide an outgoing reference beam. A detector is aligned to receive a return beam, wherein said return beam results from a reflection of said outgoing reference beam from an object outside of said distance measurement device. A diffuser is provided adjacent to the detector aligned to receive said return beam.

Abstract: In this multi-beam optical range sensor, since the diffraction grating splits output light of the light-emitting element into a plurality of beams, a plurality of beams can be outputted from the diffraction grating even with one light-emitting element. Therefore, according to this multi-beam optical range sensor, the numbers of the light-emitting elements and the light-emission side lenses can be cut down, the space on the light emission side can be reduced, and the sensor can be downsized. Also according to this range sensor, there is no need for scanning a plurality of light-emitting elements and so the detection time can be shortened.

Abstract: A device for measuring the distances (d) to far-off objects (8) and close objects by emitting modulated laser beams (1) that are reflected on the objects. The device includes an objective (2), structure(s) (12, 36, 38, 39, 40) for selecting beams, and a receiver (7). Beams are bundled by the objective, the beams not only containing the laser beams (3) reflected on the objects but also background beams (28). The beams in an associated cross-sectional region (34, 37) of the bundle are selected from a bundle of beams by the selection structure(s) (12, 36, 38, 39, 40). The cross-sectional region includes a first section (5) and at least one second section (6), laser beams (3) reflected by a far-off object being associated with the first section (5), and laser beams (3) reflected by a close object (8) being associated with the at least second section (6).

Abstract: A system and method for measuring crosswinds includes using a laser to send a signal on a signal path, and receiving response signals backscattered off of aerosols or other materials in the atmosphere along the signal path. Wavefronts of the received responses are perturbated by thermal cell turbulence in the atmosphere that perturbs optical wavefront propagation. Signals backscattered by airborne aerosols at different distances from the laser in the wavefront imager arrive at different times at the wavefront imager. Thus the wavefront perturbations vary with range, and data on the perturbed wavefront may be collected by the wavefront imager. Crosswinds cause movements in the optical perturbations over time, as the thermal cell turbulence moves. By comparing wavefronts of signals sent at different times an amount of thermal cell displacement may be determined at a series of ranges away from the laser and the wavefront imager.

Abstract: A LADAR has adjustable operational parameters to accommodate surveillance of a particular site. The LADAR includes a controller, a laser source governed by the controller to generate a laser beam pulsed at a pulse repetition rate, an optical scanner, a first set of optics, a first drive assembly governed by the controller, a second drive assembly governed by the controller, a light detector, a second set of optics for guiding laser echo pulses, and a processor coupled to the light detector to accommodate surveillance of the particular site.

Abstract: An object detecting apparatus for a vehicle has a light radiation unit and a light receiver unit disposed in a case for detecting an object or a distance to the object. When a vehicle is at a stop, the apparatus detects an output power of a laser light radiated from the light radiation unit by the light receiving unit and feedback-controls the output power of the laser light to a predetermined level based on the detected output power of the laser light. The feedback control is effected by an amplifier circuit, a pulse width detector circuit and a current regulator circuit. Thus, the output power of the laser light is reduced not to damage human eyes when the vehicle is at a stop.

Abstract: A pulse detection system for expanded time radar, laser and TDR sensors detects specific cycles within bursts of cycles. A sensor transmits and receives short bursts of RF cycles. A transmit pulse detector triggers on a selected cycle of the detected transmit burst and starts a range counter. A receive detector triggers on a selected cycle within a received echo burst to stop the range counter, thereby indicating range. Cycle selection is enabled by an analysis window of time. The detection system can provide accuracies on the order of one picosecond and is well-suited to accurate ranging along an electromagnetic guide wire.

Abstract: An electronic method for distance measurement based on pulsed laser time-of-flight is provided. The method comprises generating a wave of outgoing radiant energy pulses having a substantially stable period for providing a wave of pulses reflected from a target object and then measuring reflected energy from the pulse wave over a scanning time window. The scanning time window is shorter than the laser pulse time-of-flight to and from the measurement target. An offset between outgoing pulses and the scanning window is adjusted to capture reflected pulses at desired positions within the scanning window for selected conditions including when the outgoing wave is reflected from a reference surface and when the outgoing wave is reflected from the distance target. Distance is then calculated according to the offset and reflected energy data recorded for the selected conditions.

Abstract: A distance measuring device for a vehicle emits electromagnetic waves forward for a scan both in horizontal and vertical directions. It is judged from received light whether or not the distance to a detected object is within a specified preset range. If the distance is found to be within this range and if at least two specified conditions are satisfied, this object is regarded as a vehicle in the subsequent scans and a flag is set to this effect. One of these two conditions requires this object to have been judged as being a front going vehicle continuously over a time longer than a preset minimum time length. The second condition is that the difference between the distance to this object measured by a scan that is the highest or nearly the highest in the vertical direction and the measured distance to a front going vehicle corresponding to the object is within a predetermined range.

Abstract: A laser radar (LADAR) system is provided with amplitude-weighted spatial coherent processing. An amplitude-weighted sum of time domain signals arising from several detectors within a detector array is formed and used for range doppler processing. Weighting coefficients are chosen to be proportional to the signal amplitude present for each of the separate signals from each detector within the array. The amplitude coefficients are determined using target returned energy arising from a continuous wave (CW) porch portion of the transmitted waveform. Amplitude-weighted spatial coherent processing improves the carrier-to-noise ratio (CNR).

Abstract: The invention relates to methods and devices for recording three-dimensional distance-measuring images of an object surface by measuring light propagation time using a short-term integrated photodetector. For starting a light-induced pulse on the transmission side, a trigger signal is produced that is at the same time used on the receiving side for opening at least one integration window for receiving back-scattered light-induced pulses with a predetermined time delay. A predetermined event such as a maximum or a zero crossing is detected which, by its interval relative to the integration windows, determines a trigger delay. The trigger delay is correlated with the light propagation time and allows calculation of the object point distance d.

Abstract: A circuitry for measuring a time interval with ring oscillator has a ring oscillator formed by a plurality of delay switching units, a counter and an encoder. Wherein, the ring oscillator generates a plurality of oscillating signals when receives a pulse signal used to turn on or turn off the ring oscillator. The counter can count the numbers of the oscillating signal during an active period of the pulse signal to generate a counting value. In addition, the encoder encodes the oscillation signals generated by a plurality of delay switching unit with a certain interval of delay time. Therefore, when the pulse signal is disabled to lead to turn off the ring oscillator, one can obtain the time interval of the pulse signal based on the encode data and the counting value.

Abstract: A laser-radar receiver comprising an array of optical fibers, wherein the opposite ends of the optical fibers are connected to at least one electromagnetic radiation detector, each of the optical fibers having differing physical characteristics which result in known delays in the transmission time of pulsed electromagnetic radiation.

Abstract: An optical range finder for determining the distance comprises a focusing optical member that focuses emitted electromagnetic radiation upon a micro-mirror array. A processor controls the micro-mirror array to direct the focused electromagnetic radiation into a defined radiation pattern consistent with a lower resolution scan over a greater area and a higher resolution scan over a lesser area of interest within the greater area. A transmission optical member focuses the defined radiation pattern toward an object. A reception optical member receives electromagnetic radiation reflected from the object. A detector detects the receipt of the reflected electromagnetic radiation. A timer determines an elapsed time, between transmission of the electromagnetic radiation to the object and receipt of the electromagnetic radiation from the object, to facilitate determination of the distance between the object and the range finder.

Abstract: A ranging apparatus 1 comprises a laser light emitter 3 for emitting pulsed laser light, a reflected light receiver 4 for receiving reflected light, a distance computer 10 for finding the distance from the elapsed time until the reflected light is received, and a distance display 8 for displaying this distance. The distance computer 10 has a counter 11 for counting the frequency when the reflected light satisfies a specific condition, a table production component 12 for producing a frequency distribution table corresponding to distance by adding up the counts, a distance determiner 13 for determining as the distance to the object of measurement the point when the frequencies in the frequency distribution table exceed a threshold, and a distance selector 15 for selecting a specific distance when a plurality of distances are determined, and displaying this distance on the distance display 8.