Abstract: A liquid droplet measurement apparatus has: a first laser light source emitting a laser light; a first optical device which makes, in terms of a beam cross-section of the laser light, a beam width in a direction perpendicular to a direction of ejection of a liquid droplet, greater than a beam width in the direction of ejection of the liquid droplet, and makes light intensity of the laser light fall within a prescribed range within a range where variation in a position of the liquid droplet occurs in the direction perpendicular to the direction of ejection of the liquid droplet, at a position where the laser light from the first laser light source is irradiated onto the liquid droplet ejected; a first light receiving device which receives the laser light that has been irradiated onto the liquid droplet by the first optical device and generates a determination signal; and a first liquid droplet characteristics calculation device which calculates at least one of a volume of the liquid droplet and a velocity of t

Abstract: A beam of light or other electromagnetic field is emitted and received in a vacuum, all within an apparatus in motion. The nature of light permits the beam of light to retain the characteristics of its motion in vacuum, regardless of motion of the apparatus in which the emitted light propagates. The light beam retains its position in space relative to the direction of motion of the apparatus. Since both entities, light beam and apparatus, are disposed in the same frame of reference, characteristics of their motion can be compared. The result of this comparison represents the vector of velocity V of the apparatus which is utilized in navigation of the apparatus.

Abstract: Described herein are flexible and stretchable LED arrays and methods utilizing flexible and stretchable LED arrays. Assembly of flexible LED arrays alongside flexible plasmonic crystals is useful for construction of fluid monitors, permitting sensitive detection of fluid refractive index and composition. Co-integration of flexible LED arrays with flexible photodetector arrays is useful for construction of flexible proximity sensors. Application of stretchable LED arrays onto flexible threads as light emitting sutures provides novel means for performing radiation therapy on wounds.

Abstract: A Lidar measurement device for vehicular traffic surveillance and method for use of same are disclosed. In one embodiment, video circuitry acquires video of a field of view having a target therein. A steerable laser progressively scans the field of view to identify targets. The steerable laser then progressively, repeatedly scans a sub-field of the field of view containing the target. A processing circuit portion determines target data of the target based upon range and time measurements associated with reflected laser range-finding signals from the scans of the sub-field. The processing circuit then integrates the target data into the video such that the video may displayed with an image of the target and target data, such as a speed measurement, associated therewith.

Abstract: A sporting device may include a proximity detector, and a housing for carrying the proximity detector. The proximity detector may comprise a single photon avalanche diode for measuring the speed of an object struck by the housing. For example, the housing may define a tennis racket.

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 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 method of analyzing pulses from a flow cytometer in which particles in a fluid pass through an excitation volume of an electromagnetic radiation and interact with the electromagnetic radiation to generate signals in the form of pulses includes generating a time-dependent pulse indicative of the characteristics of one or more particles passing through the excitation volume of the electromagnetic radiation, determining a measurement window by selecting a portion of the pulse with a starting point and an ending point above a predetermined value, and calculating a first derivative of the pulse with respect to time over the measurement window.

Abstract: A device and method for measuring moving material includes a processor and operating software associated therewith; a light source for emitting at least two polarized light beams in a manner wherein the beams cross thereby creating an interference region and generate a set of fringes; a sensor aligned relative to the interference region wherein the fringes have a predetermined orientation to the directional movement of the material and wherein the sensor is operably equipped to receive scattered light emanating from the interference region and provide a time varying signal to the processor such that the processor can manipulate and convert the signal to speed and distance and a polarizing filter operably associating a polarizing filter with one of the sensor and the emitting means in a manner to substantially preclude reflected polarized light from the interference region back to one of the sensor and the emitting source.

Abstract: An automatic tracking apparatus is provided, which is capable of solving a failure occurred in an automatic tracking operation in connection with a zooming operation, and capable of tracking an object in a stable manner, while a zooming-up operation, or a zooming-down operation is carried out in a high speed.

Abstract: A method for reducing handoff inaccuracies in a DIRCM countermeasures system comprising the step of adding a second on-axis camera to the DIRCM countermeasures system.

Abstract: A displacement measuring apparatus including: a first light detector including a first emitter illuminating optically identifiable marks disposed on a moving body, and a first light receiver detecting light through the marks; a second light detector including a second emitter illuminating the marks and a second light receiver detecting light through the marks, wherein the second light detector is arranged at a predetermined interval from the first light detector in a moving direction of the moving body; an identical point detecting unit detecting a first timing at which the first and second light detector detecting an identical mark among the marks, and a second timing; a velocity calculating unit calculating a velocity of the moving body by using the first and second timing determined by the identical point detecting unit; and a time-sharing light emitting unit allowing the first and second emitter to emit the light in a time-sharing manner.

Abstract: A method and an arrangement are provided to determine the speed of the wind, which acts on a wind-blade of a wind-turbine. An optical-signal with a known frequency is sent from an optical-transmit-unit to a joint measurement volume. The optical-signal is scattered and reflected by atmospheric particles of the joint measurement volume. The optical signal is shifted in its frequency due to the Doppler-principle, too. The frequency-shifted optical signal is received by a receive-unit. The frequency-shifted optical signal is compared with the sent optical-signal to determine the wind-speed based on the shifted frequency, which is caused by the atmospheric particles.

Abstract: A traffic violation or event detection, recording and processing system and method is disclosed which includes at least one camera (20 and 30) for monitoring a region under surveillance (31 and 33); means for supplying independently sourced and verifiable time, date and location of a violation; a storing means (54) for storing continuous images taken by the camera; a non-intrusive violation detection means for detecting vehicle presence and movement and for providing an indication of a violation; and processing means for identifying images stored in the storage means and which relate to a violation detected by the violation detection means so that images associated with a violation are identifiable and can be processed to provide evidence of the violation and also identify the vehicle associated with the violation.

Abstract: A method for determining a flow rate of a fluid is provided. The method includes heating an aliquot of the fluid at a first position of a fluid-delivery channel, illuminating fluid in the fluid-delivery channel at a second position downstream from the first position, measuring an amount of light reflected from the illuminated fluid to determine a change in the amount corresponding to the heated aliquot passing the second position, and calculating the flow rate of the fluid based upon a distance between the first position and the second position and a time between the heating the aliquot and the heated aliquot passing the second position.

Abstract: A computer implemented method for utilizing a plurality of self-activating display shaping devices to provide shape adjustment information for a digital image projected on a display is disclosed. In one embodiment, the plurality of display shaping devices are automatically activated, the plurality of display shaping devices defining a desired digital image shape for a display. In addition, the plurality of display shaping devices is utilized to identify an actual projected digital image shape. The actual projected digital image shape is then compared with the desired digital image shape for the display. Correction information is then provided for adjusting the actual projected digital image shape to approximate the desired digital image shape for the display.

Abstract: A Lidar measurement device for vehicular traffic surveillance and method for use of same are disclosed. In one embodiment, video circuitry acquires video of a field of view having a target therein. A steerable laser progressively scans the field of view to identify targets. The steerable laser then progressively, repeatedly scans a sub-field of the field of view containing the target. A processing circuit portion determines target data of the target based upon range and time measurements associated with reflected laser range-finding signals from the scans of the sub-field. The processing circuit then integrates the target data into the video such that the video may displayed with an image of the target and target data, such as a speed measurement, associated therewith.

Abstract: The invention is related to a laser diode based multiple beam laser spot imaging system for characterization of vehicle dynamics. A laser diode based, preferably VCSEL based laser imaging system is utilized to characterize the vehicle dynamics. One or more laser beams are directed to the road surface. A compact imaging system including an imaging matrix sensor such as a CCD or CMOS camera measures locations or separations of individual laser spots. Loading status of vehicles and vehicles' pitch and roll angle can be characterized by analyzing the change of laser spot locations or separations.

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: The subject matter of the invention is a method of correcting a volume imaging equation for more accurate determination of a velocity field of particles in a volume, said volume being captured from different directions by at least two cameras, a coarse calibration of the position of the cameras relative to each other and relative to the volume of concern being carried out first by determining an imaging equation that associates with the coordinates (X, Y, Z) of a point in the volume the corresponding camera picture coordinates xi, yi of each camera i, all the cameras then capturing simultaneously in the same unchanged position particles in a volume, the position (X, Y, Z) of a particle in the volume being approximated by means of a known triangulation method using the calculated position xi, yi of a particle in the camera pictures, this position (X, Y, Z) being imaged through the original imaging equation onto a position xi?, yi? in the camera images of the at least two cameras, a correction factor for the im

Abstract: An assembly structure and method for housing a remote lens unit assembly of a laser Doppler velocimeter. The housing includes one or more transceiver telescopes and an optical window. The transceiver telescopes are aligned such that optical beams from the mounted optical transceiver telescopes cross paths at the optical window. The housing is mountable on a wind turbine.

Abstract: Fluid flow meters and methods for measuring different aspects of fluid flow with a non-contact sensor are provided. In some cases a fluid flow gear meter is provided with a fluid chamber that is sealed with a cover portion carrying the non-contact sensor. An optional separation member may be located between the cover portion and the chamber to seal the chamber. In some cases the cover portion and/or separation member are configured to transmit visible light to allow viewing of the fluid chamber, through material selection and/or the presence of viewing cavities within the material. The flow meter is optionally configured to prevent or reduce the transmission of ambient environmental radiation into the flow meter to lessen the likelihood that it may adversely affect an optical non-contact sensor used to detect movement of gears within the chamber.

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: 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: Systems and methods for sensing air includes at least one, and in some embodiments three, transceivers for projecting the laser energy as laser radiation to the air. The transceivers are scanned or aligned along several different axes. Each transceiver receives laser energy as it is backscattered from the air. A computer processes signals from the transceivers to distinguish molecular scattered laser radiation from aerosol scattered laser radiation and determines air temperatures, wind speeds, and wind directions based on the scattered laser radiation. Applications of the system to wind power site evaluation, wind turbine control, traffic safety, general meteorological monitoring and airport safety are presented.

Abstract: Systems and methods are disclosed for measuring a distance, a velocity, etc., of a target using coherent laser radiation. In one example, a method is provided comprising measuring a time required for a light pulse to travel to and from a target, the light pulse reflecting from the target, and determining the distance to the target based on the measuring. The method also comprises measuring a Doppler shift of the reflected light pulse using an optical detection technique and determining the velocity of the target from the Doppler shift. In a further example, a system is disclosed comprising a transceiver, a coherent source, an optical system and a detector configured to measure the distance to the target based on a measured time for a light pulse to travel to and from the target. The system is also configured to determine the velocity of the target from a measured Doppler shift.

Abstract: A method for measuring a velocity of an object surface relative to a sensor having a plurality of light-sensitive elements arranged spaced apart from one another. Each light-sensitive element produces an element signal indicative of detected brightness. The method includes receiving element signals at intervals of time, producing a frequency signal according to a spatial frequency filter method, producing a correlation signal according to an image processing method, and monitoring the produced frequency signal regarding at least one of a frequency value and at least one quality feature of the frequency signal. The method also includes selecting a produced signal for determining the velocity of the object surface relative to the sensor, and selecting the correlation signal in the event that at least one of the frequency signal lies below a threshold frequency value and the frequency signal fails to achieve a threshold quality feature value.

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: Method for monitoring the velocity of growing polymer particles flowing in a two-phase stream during a polymerization process, said method comprising measuring the degree of attenuation in the propagation of light in said two-phase stream by means of a photometric instrument, said photometric instrument comprising: one or more transmitting optical waveguides connecting one or more light sources to said two-phase stream, one or more receiving optical waveguides connecting said two-phase stream to a light detector.

Abstract: A sound-creation interface is used to create a sound-creation instrument such as a musical instrument. The musical instrument includes a mechanical-human interface such as a set of keys, strings or breathing pipe for user actuation and control of the system, a mechanical-electrical interface receiving inputs from the mechanical-human interface and for converting those inputs to a machine comprehensible signal and an electrical/processor interface receiving signals from the mechanical electrical interface and converting those signals into a processor comprehensible form. A processor receives processor comprehensible signals from the electrical-processor interface and includes a processor component and a memory component. The system allows simplified interaction between the user using the mechanical interface and the processor providing an improved sound-creation interface.

Abstract: A real-time in-situ sensor system is provided for measurement of bioluminescence and determination of bioluminescence surface signature. The system measures bioluminescence in the wake of a submerged moving object as well as ambient light levels outside of the wake. Along with measurements of depth and water-quality parameters including turbidity, temperature and salinity, the surface signature of the induced underwater bioluminescence can be calculated by considering light transmission and attenuation through water. With this real-time information, the operator of the submerged moving object can employ tactical maneuvers to affect the resultant surface signature.

Abstract: A method of determining individual velocity associated with one or more molecular species moving through a fluid medium involves obtaining multiple temporal images of the one or more species moving through the medium, analyzing the temporal images using multivariate image analysis to obtain temporal profiles of principal components, and determining individual velocity of the one or more species using the temporal profiles. Multiple species can be identified using the one or more individual velocities or ratio thereof.

Abstract: A thermal flow meter for use in dialysis is described, that uses a thermal wave to generate a signal in the fluid for which the flow rate is to be measured. The phase angle of the thermal wave signal changes when traversing downstream. The phase difference between the signals received downstream, compared with a reference excitation source signal is measured, and used to determine the flow rate of the fluid.

Abstract: The invention relates to traffic flow monitoring devices. The system includes stationary traffic monitoring points that includes reading devices to receive data from electronic tag located on a vehicle, and is connected to a remote server that includes a database of vehicles and associated electronic tags, and their owners. The stationary traffic monitoring points are in the form of autonomous small-sized computer devices with a cellular communication module, and includes automatic devices for photo-video-radar recording and for processing information about vehicles and traffic situation, and with automatic software tools for determining the parameters of the vehicles, traffic laws and for comparing them with the permissible parameters for the particular road section.

Abstract: An object detection system for a vehicle includes an imaging device, an image processor and a Lidar device. The imaging device is operable to capture image data representative of a scene exterior the vehicle. The image processor processes image data to detect an object of interest in the field of view of the imaging device. The Lidar device is responsive to the image processing so as to have its line of sight guided to point toward the detected object of interest. The Lidar device is operable to measure the distances between the host vehicle and the detected object of interest.

Abstract: A physical quantity sensor includes: a semiconductor laser which emits laser light to a measurement target; an oscillation wavelength modulating device that operates the semiconductor laser such that at least one of a first oscillation period and a second oscillation period alternately exists; a detector that detects an electrical signal including interference waveforms, the interference waveforms being caused by a self-coupling effect of the laser light and return light from the measurement target; a signal extracting device that measures each cycle of the interference waveforms whenever the interference waveform is input; a cycle correcting device that compares each cycle of the interference waveforms with a reference cycle to correct the cycles of the interference waveforms; and a calculating device that calculates at least one of displacement and velocity of the measurement target based on each of the cycles of the interference waveforms corrected by the cycle correcting device.

Abstract: The invention relates to a Method for determining the flow of a fluid close to a surface of an object immersed in the fluid by analyzing at least one confocal measurement volume in the fluid, comprising the steps of: focusing light into the at least one confocal volume within the fluid; detecting and determining of at least one optical parameter of at least one particle comprised in the confocal volume; and determining the flow velocity of the fluid based on the determination of the at least one optical parameter using a correlation function, in particular an auto correlation function or a cross correlation function. Furthermore, the invention relates to an object immersed in a fluid and comprising a measuring device for carrying out the method.

Abstract: Broadband light, for example, from a Fabry-Perot quantum cascade laser, is shone onto a sample, and spectral data concerning the broadband light reflected from the sample is collected. The spectral data is analyzed to determine information about one or more substances in the sample. For example, if the sample contains micro-organisms, such as bacteria or fungus, the biological classification(s) (e.g., species) of the micro-organisms can be determined from the spectral data. As another example, if the sample contains virus, the biological classification(s) (e.g., species) of the virus(es) can be determined from the spectral data. As yet another example, if the sample contains particles, size, location and velocity can be determined from the spectral data.

Abstract: A fluid observation apparatus 20 can perform a method for observing a fluid by PIV. The method for observing a fluid includes capturing an image of inorganic particles in a fluid for flow observation 30 by irradiating the fluid for flow observation 30 passing through a flow channel with light, the fluid for flow observation 30 containing inorganic particles to be observed each having a planar surface, a dispersion medium to be observed, and a viscosity modifier. The fluid for flow observation 30 is high-viscosity non-Newtonian slurry containing inorganic particles. The fluid for flow observation 30 may be a simulated fluid for a fluid for flow analysis. The simulated fluid closely resembles the particle size of inorganic particles to be analyzed and the viscosity of the fluid for flow analysis. The fluid for flow analysis contains the inorganic particles to be analyzed and a dispersion medium to be analyzed.

Abstract: A method and device for determining anemometric parameters of an aircraft. The device (1) comprises four laser anemometers (A1, A2, A3, A4) that are mounted in pairs (CA, CB) symmetrically on the aircraft and means (4, 5) for determining the angle of sideslip and the angle of incidence of the aircraft, using measurements taken by these laser anemometers (A1, A2, A3, A4).

Abstract: An optoelectronic safety sensor (10) is set forth for the contactless measurement of paths and/or speeds of the safety sensor (10) or of a first object connected in a fixed position to the safety sensor (10) with respect to a second object (12) moved relatively to the first object, which form a potential source of danger, wherein the safety sensor (10) has a light source (20), a light receiver (16) with a plurality of light reception elements and has an evaluation unit (22), with the evaluation unit (22) being configured to determine by means of an optical correlation process and/or by evaluation of the optical flow the path and/or the speed from at least two images of a surface structure (18, 18a, 18b) of the second object (12) taken sequentially by the light receiver (22).

Abstract: A measuring device includes a VCSEL of a first-order or high-order single mode emitting laser beams, a driving part configured to drive the VCSEL, a detecting part configured to detect an electric signal relating to feedback lights generated when laser beams are projected onto an object, and a calculating part configured to identify a direction of movement of the object on the basis of the electric signal detected by the detecting part.

Abstract: The invention relates to a method for Doppler light detection and ranging (LIDAR) measurement of speeds. A laser beam is directed at the medium to be measured, and radiation which is then emitted by the medium is measured by a detector. In order to allow better control of the dynamic range of a direct reception Doppler LIDAR apparatus, a multiplicity of laser pulses can be transmitted per measurement, and a multiplicity of laser pulses can be received by the detector per measurement. A direct reception Doppler LIDAR apparatus can be suitable for carrying out the method.

Abstract: Devices capable of capturing still and motion imagery are integrated with an accurate distance and speed measuring apparatus. By measuring the changing distance of the target over that time, a target's speed can be determined. At substantially the same time as the target's speed is determined, imagery of the target is captured in both a still and moving format. Using a queuing mechanism for both distance and imagery data along with time stamps associated with each, a target's image, both in motion and still, can be integrated with its speed. In situations in which a still image is unavailable, a target's speed can be associated with a portion of a continuous stream of motion imagery to a point where a positive identification can be captured with a still image.

Abstract: The present invention concerns a single-particle LIDAR anemometry method and system comprising the continuous emission of one or more light beams through a gas containing particles, said beam being focused onto a measurement volume, a step of detecting a signal backscattered by particles passing through said volume, the method being characterized in that it comprises at least the following phases: determining in a time period ?t the frequency of each of the pulses included in the backscattered signal; distinguishing pulses based on duration and/or intensity and/or frequency-modulation criteria; and estimating the displacement velocity of said beam relative to the gas from several of the frequencies determined over the time period ?t excluding those corresponding to the pulses distinguished during the preceding step A notable application of the invention is for the measurement of the airspeed of an aircraft

Abstract: The invention relates to a method for light detecting and ranging (LIDAR) measurement of speeds, in which a laser beam is directed at the medium to be measured, and radiation which is subsequently emitted from the medium (16) is measured by a detector. In order to optimize the measurement, a spatial measurement range can be selected by activation and/or deactivation of the detector for at least one predetermined or regulated time duration of less than about 500 ?s after emission of a laser pulse to the medium to be measured. Furthermore, a direct reception Doppler LIDAR apparatus can be used to perform the method.

Abstract: A displacement measuring apparatus 100 which measures a displacement amount of a moving object 102 includes a light source that irradiates the moving object 102 using luminous flux emitted from a light emitting area 101, a photo diode array 104, 105 that includes a plurality of light receiving areas in a movement direction of the moving object 102 and that forms an image of the luminous flux reflected on a plurality of indentations 103 of the moving object 102 to receive light, and a measurement unit that measures the displacement amount of the moving object 102 based on a movement amount of a light emitting area image 106 that is formed on the photo diode array 104, 105 by forming the image of the luminous flux.

Abstract: A method and apparatus for determining gas velocity, which includes generating transmitted radiation having an expected transmission frequency, detecting backscattered radiation, and determining gas velocity in dependence upon any Doppler shift of the frequency of the backscattered radiation, determining a transmission frequency of the transmitted radiation; detecting any difference between the measured transmission frequency and the expected transmission frequency and generating a feedback signal therefrom, and determining gas velocity using said feedback signal.

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: The subject of the present invention is a laser anemometry probe for optical homodyne detection of frequency offset by Doppler effect, comprising two devices (DERF1, DERF2) for transmitting/receiving beams in two different directions, avoiding duplicating a plurality of elements of a mono-axial laser anemometry probe.