Abstract: Apparatuses and methods determine positional information from a reflected optical signal for an object on a per pixel basis. A spread spectrum imaging system includes a transmitting module transmitting a transmitted optical signal that illuminates a target space and contains a transmitted pulse that is modulated with a first pseudo-noise (PN) code. The imaging system includes a receiving module that receives a reflected optical signal from an object. The reflected signal is processed by an optical array that detects a detected signal from the reflected optical signal, where the detected signal contains a plurality of pixels spanning a target space. When the determined PN code corresponds to the selected PN code, image information and the positional information is presented for the object. When different positional information is obtained for different pixels in the image, the imaging system may determine that different objects appear in the received image.

Abstract: Tools and techniques for estimating elevations, including without limitation tools and techniques that employ mobile stations with laser detectors for receiving a beam emitted from a laser source and estimating an elevation of the mobile station based on the received beam. In some instances, a mobile station may be configured to identify, based on some or all of a variety of factors, a situation in which the elevation of the detector is likely to change to the extent that the slope of the emitter needs to be adjusted to account for this change in elevation. The mobile station may also be configured to inform the laser source that the slope of the emitted beam should be adjusted. In response, the laser source may adjust the slope of the emitted beam accordingly.

Abstract: An opto-mechanical anemometer is particularly adapted to measure fluctuations in the flow of a turbulent fluid such as can be applied in the measurement of wind turbulence for meteorological purposes, the turbulent flow of fluid through a pipe or conduit, or the flow of air through a tube from the breath of a patient for medical diagnostics. An optical fiber is positioned in the flow path of the fluid and fixed motionless at one end. The free end is caused to bend in response to fluctuations in the flow. A beam of light is projected out the free end of the optical fiber toward a stationary optical detector placed in the path of the beam, which is sensitive to the point of maximum intensity of the beam of light. Deflection of the optical fiber translates into movement of the light beam over the detector, allowing measurement of the speed and direction of the fluid flow in two orthogonal planes.

Abstract: A method and apparatus are provided for sensing the mass flow rate of a fluid flowing through a pipe. A light beam containing plural individual wavelengths is projected from one side of the pipe across the width of the pipe so as to pass through the fluid under test. Fiber optic couplers located at least two positions on the opposite side of the pipe are used to detect the light beam. A determination is then made of the relative strengths of the light beam for each wavelength at the at least two positions and based at least in part on these relative strengths, the mass flow rate of the fluid is determined.

Abstract: A method for transitioning a target from a missile warning system to a fine tracking system in a directional countermeasures system includes capturing at least one image within a field of view of the missile warning system. The method further includes identifying a threat from the captured image or images and identifying features surrounding the threat. These features are registered with the threat and image within a field of view of the fine tracking system is captured. The registered features are used to identify a location of a threat within this captured image.

Abstract: A housing for a control device includes an enclosed cavity configured to secure an optical detection system, including a light source and a sensor, and a face of the enclosed cavity configured to include a window to allow light from the light source to scatter light off of a surface and configured to allow reception of the scattered light on the sensor. In this configuration the housing is structured to prevent exposure of the optical detection system to external elements such as the surface. Also disclosed is a homodyning system for use with a coherent light source optical pointing device.

Abstract: The invention is a line of sight wind detection system that has a laser with an output that is directed at a target. The system also has a receiver with a Hartmann aperture array receiving a reflected beam impinging on the Hartmann aperture array. A multiple pixel sensor senses a number of spots of light from the Hartmann aperture array. An analyzer receives an output from the multiple pixel sensor and determines an effective wind speed along a line of sight using a position of the spots. The system takes advantage of the fact that the wind along the line of sight will result in a shift in the angle of the wave front of the reflected beam. This shift in the angle of the wave front contains all the information of the cumulative effect on a projectile fired at the target.

Abstract: A device (100) and method (300) for enhancing range detection accuracy in ultrasonic touchless sensing applications can include transmitting (302) an ultrasonic signal intended to reflect off a finger and produce an echo, receiving (304) the echo, saving (306) most recent echoes to a history (400), selectively discarding (308) echoes less recently saved in the history to produce a sparse history, identifying (310) a relative phase of the echo with respect to a previously received echo in the sparse history, tracking (312) a location and a movement of the finger from an arrival time of the echo and the relative phase, and providing (314) touchless control to a user interface control in accordance with the location and the movement of the finger.

Abstract: A laser-system comprises master-oscillator/power-amplifier (51) whereby the master-oscillator comprises a pulsed diode (3) and a pumped active optical fiber power-amplifier (9). Substantially all guides of laser light (5, 9, 31, 29, 33, 25, 35, 39, 45) are optical fibers. The pulsed diode (3) is not temperature stabilized. To reduce nevertheless amplified spontaneous emission generated in the optical fiber amplifier (9), a narrow band-pass filter unit (29) is used. Filter unit (29) has a central wavelength with a temperature dependence which is matched to the temperature dependent wavelength shift of the pulsed diode (3).

Abstract: A method and apparatus image a target in a SAL system. The method includes receiving on-board a platform a target designation originating from a laser source off-board the platform; homing the platform on a target responsive to the received target designation; imaging the target from the target designation; and aiming the platform at a point on the target selected from the image. The apparatus includes a receiver capable of receiving and imaging a target designation originating from a laser source off-board the apparatus; at least one flight control mechanism; and a controller. The controller is capable of processing a received target designation and issuing navigation control guidance commands to the flight control mechanism to: home the apparatus on a target responsive to a received target designation; and aim the apparatus at a point on the target selected from the image of the target.

Abstract: A movable-body-speed-detecting apparatus includes a movable body capable of moving linearly and/or circularly, a plate fixed to the movable body, the plate having a predetermined length in a direction in which the movable body moves, and light emission/reception means arranged such that light output from a light-emitting element enters a light-receiving element. The plate has a window section that passes between the light-emitting element and the light-receiving element in accordance with movement of the movable body and that blocks or allows passage of light to the light-receiving element. The apparatus further comprises speed calculation means for calculating the speed of the movable body by converting the amount of light received by the light-receiving element into a signal and measuring the signal.

Abstract: An optical method and apparatus are described for the measurement of properties of a travel vehicle or a travel surface upon which the travel vehicle travels, which includes providing an incident light from a light source to the travel surface, collecting light reflected from the travel surface, determining a surface induced Doppler shift from the incident and collected light and determining at least one of a motion property of the travel vehicle and a surface property of the travel surface based on the determined surface induced Doppler shift.

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: The measurement method of the displacement speed of a moving element with respect to a fixed element is performed by means of an optic measuring device comprising a first reference sensor and a plurality of distinct second measurement sensors substantially aligned along the axis of movement of the moving element. The measurement method comprises determination of estimated speeds by correlation of the signals supplied by the reference sensor and each of the measurement sensors, and calculation of a mean speed of said estimated speeds.

Abstract: Various light emitting diode (LED) based measurement systems and methods are provided. One system includes one or more arrays of LEDs arranged along a flow path of a sample. The array(s) are configured to illuminate the sample as the sample moves along the flow path. The system also includes one or more detectors configured to detect light resulting from illumination of the sample by the array(s). One method includes illuminating a microsphere at different positions along a flow path of the microsphere. The method also includes detecting light resulting from the illumination to produce individual output signals corresponding to the illumination at the different positions. The method further includes combining the individual output signals to produce a single output signal having a signal-to-noise ratio that is greater than a signal-to-noise ratio of the individual output signals.

Abstract: A relatively low-cost sensor can accurately detect, identify and track rapidly moving objects such as missiles, rocket propelled grenades (RPGs), mortars, explosive-driven fragments, bullets, shells, sports projectiles (baseballs, golf balls, tennis balls, arrows, etc.), and other types of objects. Systems that would incorporate such a sensor include military devices such as Active Protection System (APS), warning sensor systems, counter-fire systems; commercial devices such as an accurate baseball strike zone monitor, tennis ball line monitors, and arrow speed and flight characteristics monitors. The optical sensing system detects, identifies and tracks rapidly moving objects. The system is designed to be low-cost, rugged, highly reliable, and have a low False Alarm Rate (FAR). The system can accurately record signals from rapidly moving targets and then process this information with sufficient time to send a firing signal or take other action as appropriate.

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 light wave radar apparatus includes a frequency deviation detecting unit 12 for detecting a frequency deviation fchirp of a light signal, and a weighted average processing unit 13 for determining a systematic error ?Voffset from the frequency deviation fchirp detected by the frequency deviation detecting unit 12, and subtracts the systematic error ?Voffset from a wind velocity VW calculated by a Doppler signal processing unit 11. As a result, the light wave radar apparatus can carry out a measurement of the wind velocity VW with a high degree of precision.

Abstract: A method of sensing movement or proximity of objects by optical reflection is provided. The method includes the steps of transmitting a train of optical pulses towards a destination, sensing optical pulses reflected from the destination, and sensing and evaluating movement or proximity characteristics of objects at the destination with reference to variation in pulse width between transmitted and reflected optical pulses.

Abstract: A method for non-contact measurement of the velocity and/or the length of an extrudate moved forward in the longitudinal direction, in particular of a cable during the production.

Abstract: A method of detecting the velocity of a moving object comprising the steps of: passing a beam of coherent light through an optical mask having a pattern of alternating opaque and non-opaque regions formed thereon, whereby an image of alternating light and dark fringes is projected along the length of the light beam; causing the moving object to pass through the projected image such that a portion of the light beam is reflected from the moving object as a series of pulses; detecting the reflected light pulses and the frequency of the pulses; and calculating the velocity of the object as a function of the pulse frequency and the known separation of the fringes of the image.

Abstract: A velocimetry apparatus and method for the collection of target-specific images of fluid motions are disclosed. The apparatus includes a camera and a light source. The camera collects and provides images of the fluid showing instantaneous positions of particles in the fluid. The light source provides a light sheet (two-dimensional) or volume (three-dimensional) to illuminate the particles. The camera and the light source are powered by portable energy sources and measure instantaenous velocity of the fluid in a field of view. Shape and distance between first camera, the light source and the portable energy sources are so configured that the apparatus is a self-contained apparatus portable by a diver during operation thereof.

Abstract: A method for repairing turbine blades by replacing at least a part of the blade profile, the method having: a) manufacture of a replacement blade part; b) separation of the damaged area with a standardized cutting plane, leaving behind a remaining blade; c) matching of the replacement blade part to the actual geometry of the remaining blade; d) connecting or joining of the replacement blade part to the remaining blade by soldering of at least one web and welding of an outer contour.

Abstract: An optical flow sensor is presented that directly measures the translational component of the optical flow experienced by the sensor while it is on a moving platform. The translational optical flow is measured by using a gyro to measure the platform's angular rates and then incorporating these angular rates in the optical flow computations in a manner that bypasses lags in the optical flow sensor measurement. In one embodiment, individual “velocity report” optical flow measurements have their rotational component removed before these velocity reports are utilized in the remainder of the optical flow algorithm. In another embodiment, a movable window and shifting techniques are used to form a windowed image that has no rotational optical flow components. In another embodiment, an optical flow sensor is mounted on a gimbal and held to point in one direction even as the platform on which the optical flow sensor is mounted moves.

Abstract: A device and a method for triggering at least one deceleration device and/or one output-determining actuator element of a vehicle propulsion system, in particular for automatic longitudinal vehicle regulation, a first surroundings sensing device being provided, which delivers longitudinal value-optimized measured values, a second surroundings sensing device being provided, which delivers object lateral dimension-optimized measuring values, and an analyzer device being provided, which receives the output signals of the first and second surroundings sensing devices and the measured values of the first and second surroundings sensing devices being used for object identification. The device and the method are furthermore suitable for initiating or performing vehicle deceleration for collision avoidance or for alleviating the severity of a collision.

Abstract: A visual sensor for generating an array of binarized feature signals based on a visual field is provided. The visual sensor comprises an array of photoreceptor circuits capable of generating photoreceptor signals based on the visual field, an array of feature detectors capable of generating feature signals based on the photoreceptor signals, and a reconfigurable binary generator array capable of generating binarized feature signals based on the feature signals.

Abstract: An airborne wind profiler for an aloft aircraft includes a system bus for receiving a GPS signal including a time and position solution and an attitude signal representing heading, roll, pitch, and yaw of the aircraft. An optical module includes at least one laser Doppler velocimer including an mount allowing the at least one laser Doppler velocimeter to articulate in at least two axes, thereby to orient the laser Doppler velocimeter below a horizon to generate at least one first velocimeter signal. The velocimeter signal includes at least one first radial velocity of a first wind-borne aerosol and a first orientation of the at least one laser Doppler velocimeter relative to the aircraft. A processor module receives the first velocimer signal at the time from at least one laser Doppler velocimeter.

Abstract: An object recognition apparatus in a subject vehicle includes a radar unit for transmitting a plurality of laser beams in a scan range spread in horizontal and vertical directions of the subject vehicle and receiving a reflection, a recognition unit for recognizing the object in front of the subject vehicle based on the reflection, a determination sub-unit in the radar unit, a calculation sub-unit in the radar unit; and an adjustment sub-unit in the radar unit. The radar unit is so disposed in the subject vehicle with a center axis of one of the plurality of the laser beams aligned with a target angle that the determination sub-unit uses coverage in the vertical direction of the laser beam being sufficient for variation of heights of the reflector on the object at a first distance detected by the radar unit as the predetermined condition for selecting of the object.

Abstract: A detector (210, 310) that is configured to detect ghost-coherent reflections (260) produced by a superluminescent diode (SLD). The ghost reflections (260) are detected based on the optical coherence produced by reflections from surfaces (350, 450, 555) that are at integer multiples of the reflections within the SLD cavity (213), and thus exhibit the fine resolution discrimination that is typical of optical coherent detectors. In a preferred embodiment, the detector (210, 310) is configured to detect ghost reflections (260) from a surface at a particular multiple of the internal reflections. Ghost reflections (260) at other multiples are optically attenuated (330), or, if such reflections are known to be non-varying, canceled via a calibration procedure.

Abstract: An L2F velocimeter comprises a probe for insertion into a fluid, the probe having an open area therein to allow the fluid to pass through. The probe comprises an illumination system to direct a pair of light beams, separated by a distance, through the open area, and a collection system to collect forward scattered light scattered from particles in the fluid. The collection system has an optical axis in common with the illumination system. The velocimeter further comprises an electro optical assembly connected to the probe to provide light to the illumination system, to receive light collected from the collection system, to measure a lapse time in fluctuations of the forward scattered light created by particles passing through the pair of light beams and to calculate the velocity of the fluid based on the lapse time and the separation distance.

Abstract: A system that includes a laser designator configured to continuously designate a target with a pulsed laser spot. The system includes a sensor and associated processing system configured to receive a reflection of the laser spot, convert the received energy to plurality of signals, processing the signals for detecting true reflected signals and process the true reflected signals for generating target related action. The sensor and associated processor are configured to detect the true signals notwithstanding an inherent low Signal/Noise ratio of below 4 of the received signals from due to low pulse power of the laser designator and distance to target.

Abstract: Disclosed is a method for identifying a moving object, comprising: a driving-in step of moving a moving object into a passage, a velocity measuring step of measuring a moving velocity of the moving object, a light beam emitting step of emitting light beams from one side of the passage, a light beam receiving step of receiving the light beams not shielded by the moving object at other side of the passage, a profile determining step of determining a profile of at least one portion of the moving object based on the received light beams and the measured moving velocity of the moving object, and an identifying step of determining type of the moving object by comprising the profile of the at least one portion of the moving object with information of moving objects stored previously.

Abstract: The invention relates to a method for measuring air turbulences with a lidar system, particularly on board aircraft during which a pulsed expanded laser beam (12) of a predetermined wavelength is emitted up to a spatial area and light backscattered from this spatial area is received. At a first point in time t1 and at a second point in time t2 after emitting a laser pulse (L), the intensity distribution in the cross-section of the backscattered light is measured, and an air turbulence in a measuring field defined by points in time t1 and t2 is determined from the comparison of both intensity distributions. Images of speckle patterns are recorded with the aid of cameras (21, 22). An evaluation unit (30) conducts a cross correlation in order to render the turbulence visible and to display it on a monitor (35).

Abstract: A measurement apparatus having a measurement light source for emitting measurement light, a projection unit on which reflected light formed when the measurement light is reflected from the mirror plane is projected as a projected light spot, an image pickup unit for picking up an image of the projection unit on which the reflected light is projected as the projected light spot, a control unit for controlling an inclination of the mirror plane and a measurement unit for measuring a quantity of movement of the projected light spot, which moves according to a change of the inclination of the mirror plane, on the basis of the image of the projection unit. This enables the measurement of a deflection characteristic of a mirror system having the mirror plane variable to arrange the inclination within a short period of time and with high accuracy.

Abstract: A flow velocity detector for detecting a flow velocity of a fluid flowing through a flow passage is provided, the flow velocity detector including a flow passage-forming section which defines the flow passage; a stress light-emitting section which is arranged at the flow passage-forming section to receive a stress having a magnitude depending on the flow velocity of the fluid and which emits a light of which amount corresponds to a change of the received stress; and a light-receiving sensor which receives the light emitted by the stress light-emitting section. The flow velocity of the fluid is detected based on an amount of the light received by the light-receiving sensor to generate a detection signal. Accordingly, the structure is simple and small-sized, and the flow velocity of the fluid can be detected at low cost.

Abstract: Method and apparatus for contactless determination of lateral offset relative to a straight-ahead direction when an object moves relative to an object with a stochastic surface structure, in which the surface structure is imaged on at least two similar photosensors arranged behind one another at a defined separation in the straight-ahead direction and having a spatially resolving longitudinal extent transverse to the straight-ahead direction, a spatial frequency signal corresponding to the surface structure is generated by the sensors, the spatial frequency signal of a second sensor in the movement direction is read, temporally shifted relative to the spatial frequency signal of the first sensor, such that the same, at least partially overlapping surface structure is imaged on both sensors, the spatial frequency signals of the first and second sensors are correlated to determine a correlation coefficient, and the lateral offset of the correlated spatial frequency signals on the sensors is determined.

Abstract: The invention relates to an optical measurement device intended for determining a relative velocity vector {right arrow over (v)} of a carrier, such as an aircraft, with respect to a reference medium MILREF. The device includes an optical signal system EMIREC, delivering an optical signal Sinc that follows a direction called the line of sight LDV and is concentrated in a focusing zone ZOF, and means for displacing the focusing zone ZOF in the reference medium MILREF.

Abstract: A system of lasers and detectors to detect the presence of objects and determine their speed is disclosed. The system comprises of a pair of lasers and a pair of detectors focused through a single lens or a pair of lenses. An electronic board that accompanies the lasers and detectors is used to provide the logic and decision making mechanism. Data collected and processed by the system yields such information as whether an object is present, whether the object is stationary or is moving, and subsequent speed information. The described system is also capable of providing additional information concerning the characteristics of the moving object such as its profile and length, and indication of a traffic violation.

Abstract: A multiplexed set of light sources having outputs of light with various wavelengths which are combined into one beam. The beam may impinge a particle in a flow channel of a cytometer. The light leaving the flow channel may be sensed by a detector and the light distinguished according to wavelength.

Abstract: A method for measuring the velocity of a multiphase fluid flowing in a pipe. The method comprises directing at least two collimated beams of light from an illuminator through the multiphase fluid by transparent portions of the pipe. The at least two collimated beams are spaced apart in a direction of flow of the multiphase fluid by a predetermined distance. The method also includes detecting scattered, deflected and attenuated light with at least two photodetectors to produce at least two signals. The at least two photodetectors are associated with the at least two collimated beams. The method also includes calculating a cross-correlation function between the at least two signals to determine a time delay between the signals and calculating the average velocity of the multiphase fluid by taking the ratio of the predetermined distance to the time delay.

Abstract: Apparatus, for detecting at least one object and preventing receiver burn-out, mounted on a vehicle, including a laser and at least one receiver, the receiver being coupled with the laser, the laser for transmitting a beam of light and the receiver for detecting reflections of the beam of light from the object, the laser including at least one signal diode, a commutator, a power supply signal diode driver, a circulator, an erbium doped fiber (EDF), a wavelength division multiplexer (WDM), a narrow band Bragg reflector, a first fiber pump diode, an output combiner and a second fiber pump diode, the commutator being coupled with each signal diode and the power supply signal diode drive, the circulator being optically coupled with each signal diode, the EDF and the output combiner, the WDM being optically coupled with the EDF, the narrow band Bragg reflector and the first fiber pump diode and the second fiber pump diode being optically coupled with the output combiner, each signal diode generating a beam of ligh

Abstract: An apparatus for detecting a person's presence without requiring the person to provide auditory or tactile input. The invention may be incorporated into an electronic device, such as a desktop computer or notebook computer. The embodiment may employ a variety of radiation emissions to determine when a person enters the embodiment's field of detection and, in response to the person entering, activate the electronic device. This may prove particularly useful where, for example, the electronic device consumes significant power and/or may suffer deleterious effects if left active for too long.

Abstract: A sensor system with a lighting device and a detector device is specified. The lighting device is provided for emitting laser radiation of a first wavelength and laser radiation of a second wavelength different from the first. The detector device is provided for detecting electromagnetic radiation of the first and the second wavelength.

Abstract: Disclosed is a laser doppler velocity system that can easily change a focal length of laser beam, in order to measure the velocity of fluid. As the fluid lens is used in order to focus the laser beam, the lens aperture is rapidly and accurately changed at a low power to easily measure the flow-velocity and shear stress of the boundary layer of the structure within the flow field. As the optical array including the fluid lens is integrated using a diode laser as a laser light source, the laser doppler velocity system can be made in small-size. Also, as the laser doppler velocity system is inserted into the surface of the structure, it can be used as a surface flow field measurement sensor.

Abstract: A method and apparatus for measuring or determining spin characteristics of a moving object such as a golf ball (1) is disclosed. The object includes one or more detectable marks (2) or object features. Event characteristics associated with the entry, passage or exit of the marks (2) or object features are detected or recorded at a reference or boundary. Marks are physically effected by heating a region on the surface of the object to a detectably different temperature.

Abstract: A motion member (1) urged by an application spring 4 is made to collide with a surface of a sheet material supported by a support member (14) so as to be deflectable and deformable. The velocity of the motion member (1) during the collision process is detected every second by a measuring portion (17) of a laser Doppler velocimeter. A control circuit (121) measures the velocity of the motion member (1) immediately before the collision of the motion member (1) with the sheet material, the time period of deflection deformation until the sheet material collides with an opposing member (15), and the time period of compression deformation after the collision of the sheet material with the opposing member (15), and outputs a result thereof as sheet material information to a control portion (120). The timing at which the sheet material collides with the opposing member (15) is detected by an output of a piezoelectric element (16) connected to the opposing member (15).

Abstract: A velocimeter is disclosed that includes a plurality of photodetectors detecting scattered light in different directions, the light being emitted from a laser source and reflected on a moving object. The velocimeter includes an analog-to-digital conversion unit converting detection signals of the photodetectors, a velocity calculator calculating velocities of the moving object, an amplitude calculator calculating the amplitudes of the detection signals, a dropout detector detecting dropouts of the detection signals, a time keeper keeping detection times of the dropouts, a switching-time calculator calculating signal switching times, a storage memory storing the velocities, the amplitudes, and the signal switching times, and an output selector selecting one of the velocities stored in the storage memory based on the amplitudes and the signal switching times and outputting the selected velocity.

Abstract: A flow cytometer capable of using electronics to analyze a large dynamic range while avoiding and/or correcting traditional limitations of acquisition electronics. The invention allows for measuring signal characteristics, which may include but are not limited to linear peak, integral, logarithmic peak, and pulse width. Other system parameters may also be generated by the invention to indicate timing or status information. Accurate and precise measurements may be performed by correcting for input errors if needed, and by transforming the input signal to produce a more easily measured form.

Abstract: There is provided a heterodyne laser Doppler probe capable of realizing the compatibility between its photoexcitation efficiency and speed measurement efficiency, and a measurement system using the same is also disclosed. The heterodyne laser Doppler probe introduces excitation light for photoexcitation from a first optical path (2) to an optical probe (1) and measurement light for heterodyne laser Doppler measurement from a second optical path (4) to the optical probe (1). After emission from the first optical path (2), the excitation light is introduced through a reflection mirror (3) and a beam splitter (6) into a focal lens (7), and then into a measurement object (excitation object) (8). On the other hand, the measurement light for heterodyne laser Doppler measurement is emitted from the second optical path (4) and passes through a ¼ wavelength plate (5).

Abstract: The invention relates to sensors of the speed of movement of a vehicle over the ground. The sensor comprises illumination means for illuminating the surface and at least one optical sensor able to detect the radiation returned by the surface. The illumination means and the optical sensor have one and the same optical axis, oblique in relation to the surface. This arrangement eliminates the risks of specular reflection dazzling the sensor while avoiding disturbance of the measurement by variations in the height of the sensor relative to the ground.