Abstract: The present invention relates to a frequency shifter in an optical path containing a continuous laser source, and it comprises at least two frequency shift modules placed in parallel and each containing an optical propagation medium, the optical path length of which is modified according to the desired frequency shift, each of these modules being controlled separately, this shifter comprising a switch (14) which is connected to the outputs of these modules and is controlled so as to choose, at each instant, the module providing the desired frequency shift, the switch delivering, at its output, a continuous optical beam whose frequency is adjusted by contiguous sections.

Abstract: A first beam of light from a laser is split by a beam splitter into a reference beam and at least one second beam of light, the latter of which is directed into an atmosphere. Light from the at least one second beam of light scattered by molecules or aerosols in the atmosphere is collected by at least one telescope as at least one light signal. The at least one light signal and the reference beam are simultaneously processed by a common interferometer, and resulting fringe patterns are imaged onto a detector and processed by a data processor to determine at least one associated air data product.

Abstract: A computer cursor control device includes (1) a light source generating light directed toward a stationary surface, (2) an optional phase modulator, (3) an optional function generator causing the phase modulator to periodically phase shift the light, and (4) a signal processor determining a direction in which the device is moving from a beat frequency or an asymmetry in the light intensity. Another computer cursor control device includes (1) an optical element combining reference and measurement beams to form a heterodyned beam, (2) a phase modulator located in an optical path of the reference beam or the measurement beam, (3) a function generator causing the phase modulator to phase shift the reference beam, and (4) a signal processor determining a direction in which the device is moving from a beat frequency of the heterodyned beam.

Abstract: An optical navigation device and a method thereof, wherein the optical navigation device comprises a pair of linear sensor arrays which are arranged non-parallel to each other for detecting light signal. Furthermore, an algorithm including correlation and vector analysis is processed by a computation unit to determine velocity and displacement according to present and previous light signal data sequences. Hence, the linear sensor arrays adapted to be the approach of navigation device can achieve the goal of reducing the computing data, increasing operation speed effectively and reducing hardware cost because of its fewer optically sensitive elements.

Abstract: The invention provides an optical flow meter for measuring fluid flow through a pipe which obviates the need for the flow to be seeded with foreign particles. The meter comprises a fiber optic Sagnac interferometer with optical path crossing the flowing fluid. The interferometer measures velocity of the fluid by measuring the phase difference between the two beams propagating in the optical path in opposite directions. Light, which is deflected by the fluid, is collected by optical means at both sides of the optical path for calculation, the scintillating statistics and compensation for light intensity.

Abstract: Indicating relative speed is disclosed. A first grating coupled to a first moving object is illuminated using a coherent light source to generate a first diffracted beam and a diffracted order beam. A second grating coupled to a second moving object is illuminated using the first diffracted beam and the second diffracted beam to generate a third diffracted beam and a fourth diffracted beam. The third diffracted beam and the fourth diffracted beam are measured. A relative speed of the first moving object with respect to the second moving object is indicated based at least in part on the measured third diffracted beam and the measured fourth diffracted beam.

Abstract: In a distance/speed meter, first and second semiconductor lasers emit parallel laser light beams to a measurement target. A first laser driver drives the first semiconductor laser such that the oscillation interval in which at least the oscillation wavelength monotonically increases repeatedly exists. A second laser driver drives the second semiconductor laser such that the oscillation wavelength increases/decreases inversely to the oscillation wavelength of the first semiconductor laser. First and second light-receiving devices convert optical outputs from the first and second semiconductor lasers into electrical signals. A counting unit counts the numbers of interference waveforms generated by the first and second laser light beams and return light beams of the first and second laser light beams.

Abstract: In the case of a method of detecting wind velocities by means of a Doppler-lidar system (10), a laser beam of a defined frequency generated by means of a laser (11) is emitted by a transmitting device (12) toward a space area and the light backscattered from the space area is received by means of a receiving telescope (13). For determining a Doppler shift, an interferogram is generated by means of an interferometer (16), the intensity distribution of the interferogram being directly measured by means of a photodetector (17). The measured intensity distribution is compared with one or more reference patterns which had previously been determined for defined parameters and are filed in a memory device (18a). From the comparison, the Doppler shift is determined as a measurement for the wind velocity. The Doppler-lidar system (10) comprises an analyzing unit (18a, 18b) for implementing the method, having a comparison unit (18b) for the comparison of reference patterns with the measured interferogram.

Abstract: The optical tracking device of this invention comprises a lens unit, a control circuitry communicatively coupled to the lens unit, and an imaging unit optically coupled to the lens unit. The lens unit comprises at least one Micromirror Array Lens, wherein the Micromirror Array Lens comprises a plurality of micromirrors and is configured to have a plurality of optical surface profiles by controlling rotations or translations of the micromirrors. The optical tracking device of the invention further comprises an image processing unit, communicatively coupled to the imaging unit, configured to process the image information from the imaging unit and generates a control signal for the control circuit to control the lens unit. The optical tracking device of the present invention provides capability of tracking a target moving in a high speed, providing three-dimensional image information of the object, and compensating the aberration of the optical tracking device.

Abstract: A velocimetry apparatus and method comprising splitting incoming reflected laser light and directing the laser light into first and second arms, filtering the laser light with passband filters in the first and second arms, one having a positive passband slope and the other having a negative passband slope, and detecting the filtered laser light via light intensity detectors following the passband filters in the first and second arms.

Abstract: The invention relates to a Doppler frequency shift measuring device of the optical type comprising an optical signal channel delivering, through a polarization-splitting coupler, through a bidirectional signal port of the coupler, a signal light beam illuminating a reference medium, the coupler receiving, through said bidirectional port, a backscattered light beam returned by the reference medium; a reference channel providing a reference light beam for detection of the Doppler frequency shift, the frequency shift being determined by the frequency shift between the light signal illuminating the reference medium and the light beam returned by the reference medium. The reference light beam is applied to a reference port of the polarization-splitting coupler, said coupler delivering, at a port, a beat signal between the frequency of the reference light beam applied to the port and the frequency of the backscattered light beam applied to the port, possibly containing the Doppler shift.

Abstract: A method and apparatus for performing simultaneous multi-point measurements of multiple velocity components in a gas flow is described. Pulses of laser light are directed to a measurement region of unseeded gas to produce Rayleigh or Mie scattered light in a plurality of directions. The Rayleigh or Mie scattered light is collected from multiple directions and combined in a single collimated light beam. The Rayleigh or Mie scattered light is then mixed together with a reference laser light before it is passed through a single planar Fabry-Perot interferometer for spectral analysis. At the output of the interferometer, a high-sensitivity CCD camera images the interference fringe pattern. This pattern contains the spectral and spatial information from both the Rayleigh scattered light and the reference laser light. Interferogram processing software extracts and analyzes spectral profiles to determine the velocity components of the gas flow at multiple points in the measurement region.

Abstract: Linear spot velocity or position variations are measured in a scanning system by a process and apparatus.

Abstract: A novel technique using an acousto-optic modulator (AOM) as part of a heterodyne interferometer which measures optical path differences between a test signal and a reference signal is disclosed. An array of distinct frequencies are used to drive the AOM, yielding a spatially dispersed array of frequency-shifted subaperture beams of the test signal which are interfered with the wavefront to be measured and then combined with the dispersed reference signal. The frequency shifting of the AOM allows a single detector to collect the beams for signal processing to determine a measurement of the wavefront.

Abstract: Combined laser-based apparatus for determining both altitude and ground velocity of an aircraft comprises: a laser source for emitting pulsed laser beams substantially at a predetermined wavelength; a plurality of first optical elements for directing the laser beams from a first optical path to a second optical path which exits the first optical elements; a plurality of second optical elements configured to form a telescope, the second optical path and telescope field of view being fixedly co-aligned; an optical scanner for directing the second optical path and telescope field of view to desired ground positions while maintaining the co-alignment thereof; the telescope for receiving Doppler wavelength shifted reflections of the pulsed laser beams and directing the received ground reflections substantially over a third optical path; an optical filter element for separating the ground reflections of the third optical path into first and second portions that are dependent on the Doppler wavelength shift of the g

Abstract: A coherent laser radar or lidar device (2;20;84;90) for measuring wind speed is described that comprises a transmitter for transmitting a beam of light to a remote probe volume (6;54), a receiver for detecting back-scattered light and an analyzer for calculating wind velocity at the remote probe volume from the Doppler shift in frequency of the detected back-scattered light. The analyzer is arranged to monitor for the presence of, and/or to ensure the calculated wind speed is corrected for, any Doppler frequency components of the detected back-scattered light that arise from back-scatter off cloud located at a range greater than the range of the remote probe volume. It is described how the lidar (2;20;84;90) may be scanned and wind velocity components calculated by fitting the scanned line of sight velocity values to a predetermined function. Furthermore, it is outlined how an initial fit may be performed to determine which points are to be used in this calculation.

Abstract: A device for generating microwave signals, e.g., for use in a distance and speed sensor in a motor vehicle, is provided. To this end, two laser sources are operated, whose emitted radiations are distinguished from each other by a set difference in wavelength. The two lasers are arranged in such a manner that the emitted laser beams overlap spatially. A photodiode is arranged in this region in which the two laser beams interfere. From the superimposition product of the two laser beams, this photodiode generates an electrical output signal that has the differential frequency of the two superimposed laser beams. In this context, the frequency difference of the two lasers is selected so that the frequency of the generated microwave radiation lies in the range of the radar beam to be generated.

Abstract: A fiber optic filter edge detector of Doppler shifted light comprises: a laser source for emitting pulsed laser light substantially over a first fiber optic path; an optical lens for directing laser light emitted from the first fiber optic path to free-space and for receiving laser light returns from free-space and focusing the laser light returns to the first fiber optic path; an edge filter optical element fiber coupled to the first fiber optic path for receiving the laser light returns, the edge filter optical element operative to transmit a first portion of the laser light returns through a second fiber optic path and to reflect a second portion of the laser light returns through a third fiber optic path; and at least one light detector optically coupled to the second and third fiber optic paths.

Abstract: A laser velocimetry system that employs a low power laser. The laser has a power of up to about 100 mW. Light from the laser, in one embodiment, is directed through a multimode optical fiber and an optical probe to a surface of a moving sample. Doppler-shifted light from the surface is reflected back through the optical probe and multimode optical fiber to a circulator, which directs the light reflected from the surface to a second multimode optical fiber. Unshifted (i.e., non-Doppler shifted) light is also introduced into the optical signal path. The Doppler shifted reflected light and the unshifted light are then transmitted through the second multimode optical fiber to a detector, which converts the reflected light into an electronic signal. The electronic signal of the “beat” between the Doppler shifted light and unshifted light may then be digitized by an analyzer and used to determine the velocity of the moving surface. A method of determining the velocity of a moving object is also described.

Abstract: A method for identifying and determining the frequency of scattered radiation fringe patterns for applications such as particle or droplet sizing and laser Doppler velocimetery. The method utilizes a series of windowed Fourier transforms performed on an intensity profile of the scattered radiation to locate a segment where a fringe pattern is located on the intensity profile. A standard Fourier transform is then performed on the segment to determine a dominant frequency of the fringe pattern, from which a physical quantity such as diameter or velocity of the particle or droplet may be derived. The method may be utilized with a line or an array sensor to measure the fringe patterns in a spatial domain, or with a point detector to measure the fringe patterns in the time domain.

Abstract: The invention relates to an optical measurement device designed notably to evaluate the velocity of an aircraft by detection of a Doppler shift. The device for measurement by optical probe comprises at least two light beams of different wavelengths ?1 , ?2, denoted as first beam and second beam, the device illuminating a reference medium MILREF (60) by the first beam and receiving a light echo Sr reflected back by the reference medium, and the device comprising: an optical coupler COUPL (70) receiving, on the one hand, the light echo Sr reflected back by the reference medium MILREF and, on the other, the second beam, the coupler delivering a resultant wave Or comprising the second beam and the light echo Sr; an optical amplification unit AMPLI (80), of bandwidth Bopt, receiving the resultant wave Or and delivering an amplified resultant wave Ora.

Abstract: The time separation of laser pulses comprised of a relatively fixed reference pulse and a time varying doublet pulse in a doublet pulse laser radar is linearly modulated for eliminating velocity ambiguity upon reception and detection. A range-Doppler map can be directly generated which not only reveals target range and velocity, but also can be processed to indicate target motion, such as rotation.

Abstract: An optical detector measuring a movement of an object in a space on a measurement axis comprises a light source, a reflective portion, a detection unit and a converting unit. The light source comprises a resonance chamber, the light source emitting a laser beam toward the object, the laser beam contacting the object and generating a first scattering beam and a reflection beam, wherein a part of the first scattering beam enters the resonance chamber. The reflective portion reflects the reflection beam toward the object, the reflection beam re-contacting the object and generating a second scattering beam and a sub-reflection beam, wherein a part of the second scattering beam and the sub-reflection beam enter the resonance chamber. The detection unit measures an optical-electrical variation in the resonance chamber to generate an electric signal. The converting unit converts the electric signal to a movement on the measurement axis in the space.

Abstract: A method and apparatus for performing simultaneous multi-point measurements of multiple velocity components in a gas flow is described. Pulses of laser light are directed to a measurement region of unseeded gas to produce Rayleigh or Mie scattered light in a plurality of directions. The Rayleigh or Mie scattered light is collected from multiple directions and combined in a single collimated light beam. The Rayleigh or Mie scattered light is then mixed together with a reference laser light before it is passed through a single planar Fabry-Perot interferometer for spectral analysis. At the output of the interferometer, a high-sensitivity CCD camera images the interference fringe pattern. This pattern contains the spectral and spatial information from both the Rayleigh scattered light and the reference laser light. Interferogram processing software extracts and analyzes spectral profiles to determine the velocity components of the gas flow at multiple points in the measurement region.

Abstract: A method and system for controlling the wavelength of light emitted by a tunable laser. The system includes a wavelength tuner that provides information of a desired wavelength; a coupler for tapping a portion of the light from the tunable laser; and an apparatus for measuring the actual wavelength of the light. The apparatus takes the portion of the light as an input signal and splits the input signal into two beams that are directed through two paths of different optical lengths. Then, the two beams are interfered with each other in order to form a fringe pattern at an observation plane, where the fringe pattern is detected and analyzed to determine the wavelength of the light. A processor compares the difference between the desired and determined wavelengths, and sends a tuning signal to the tunable laser forming a feedback control of the tunable laser.

Abstract: An optical accelerometer, gravitometer, and gradiometer have a light source, a beam splitter, a light medium, and a plurality of mirrors. The light beam from the light source is split into two beams that counter-propagate through the accelerometer. The acceleration experienced by the accelerometer causes a phase shift in the beams, and this phase shift is used to calculate the acceleration.

Abstract: The invention concerns solid-state gyrolasers used to measure rotation speeds or relative angular positions. This type of equipment is used, in particular, in aeronautical applications. The purpose of the invention is to complete the optic devices required to control the instability of lasers, using specific optic devices that eliminate the blind region. In this way, a “fully optic” solid-state laser is obtained, without moving parts, stable, and without blind regions. These devices comprise in particular reciprocal and nonreciprocal optical rotators, arranged so that two counter-propagating optical modes travel in the cavity at sufficiently different frequencies to avoid mode locking.

Abstract: In an optical movement information detector, light emitted from a laser diode (1) is split into a first beam (10), a second beam (11) and a third beam (12) by beam splitters (2a, 2b). The first, second and third beams are converged by a condenser lens (4) upon a surface of an object to be measured (5) to form a beam spot (13) thereon. Diffused light from the beam spot (13) is received by a photodiode (6) and an output signal of the photodiode (6) is processed by a signal processing circuit (20) including an analog-digital converter (8) and a Fourier transforming unit (9). A detecting section (21) obtains, for example, a moving velocity and a moving direction of the object based on spectrum peak frequencies obtained by the Fourier transform.

Abstract: An electrophoretic medium (100) comprises at least one type of particle (108) suspended in a suspending fluid (106) and capable of moving therethrough on application of an electric field to the medium, the particles (108) including at least one electrophoretically mobile specularly reflective particle.

Abstract: An apparatus includes a transmitter portion which transmits a defined beam of eyesafe laser energy, a receiver portion which receives reflected energy from the beam, and a further portion which analyzes information in the received energy so as to detect the presence of a moving projectile.

Abstract: The invention provides a measuring sonde (1) for a hydrocarbon well, the sonde comprising a main body (2), a downstream arm (3), and an upstream arm (5), at least one of said arms being fitted with measurement means (6) for determining the characteristics of the fluid flowing in the well; said downstream and upstream arms being connected to the main body respectively via first and second sliding pivot links (A and E).

Abstract: This invention relates to a gas velocity sensor such as an air velocity sensor for use on an aircraft such that the velocity of the aircraft can be determined. There is provided a gas velocity sensor comprising an electromagnetic radiation source operable to illuminate a gas; a photodetector operable to detect electromagnetic radiation scattered from the gas; an optical path linking the gas to the photodetector; an interferometer positioned on the optical path, the interferometer having an input for receiving electromagnetic radiation scattered by the gas and an output for producing an interference pattern when the interferometer is illuminated; and a spatial filter positioned on the optical path on the output side of the interferometer, the spatial filter having regions that are relatively transparent and relatively opaque that form a structure corresponding to an interference pattern produced by the interferometer.

Abstract: The present invention includes an interferometer for VISAR. Optionally, the present VISAR system includes intracavity imaging design with converging beams and field elements to, among other possible purposes, image the array. An optional embodiment of the present VISAR system may also optionally include precision fiber arrays. Optionally, the present system may use non-collimated beams to allow intracavity access to individual channels for one or more additional delay paths.

Abstract: A system and method for detecting thrust in a remote object is disclosed herein. The system is suitable for use in connection with midcourse discrimination systems that distinguish actual targets of interest, such as warheads, from decoys. The system directs laser pulses at the remote object under observation. The system directs at least one initial laser pulse at the remote object to heat the surface material of the remote object and to create an outgas environment near the remote object. The system also directs at least one secondary laser pulse at the outgas environment, which creates very high peak power filaments that bombard the surface of the remote object. The filaments ablate the surface material of the remote object, ejecting mass away from the remote object at a high velocity. The ejection of mass imparts thrust to the remote object, resulting in an imparted differential velocity dependent on the mass of the remote object.

Abstract: A contact free optical motion sensor for an inertial reference system. One or more image acquisition systems are adapted to produce a series of overlapping images of a gas bearing supported spherical inertial sensor assembly. A controller coupled to receive the series of overlapping images applies a delta detection algorithm to the series of overlapping images to determine the distance, the direction of movement of the inertial sensor assembly and the resulting relative position of the gas bearing supported spherical inertial sensor assembly. The controller further calculates the rotational velocity of the inertial sensor assembly based on a time sequence between the received series of image signals and the distance moved.

Abstract: Systems and methods for measuring the flow of a liquid along a conduit are disclosed. A heat source applies thermal energy to a portion of a liquid flowing along a conduit thereby elevating its temperature. A light source generates a first beam that passes through the liquid in the conduit downstream from the position of application of the thermal energy and an optical detector receives this beam in combination with a second beam that is not passed through the liquid in the conduit and measures a change in intensity of a combined beam. The time required for the heated portion of the liquid to move from the point of application of thermal energy to the point at which the beam passes through the liquid is measured. This measured time, along with the distance of separation of the heat source and the optical sensing means permits calculation of the velocity of the liquid in the conduit.

Abstract: The invention pertains to the sensing and measurement of infrasound (pressure variations with frequency content under 10 Hertz). The invention measures the infrasound pressure variations and then attenuates undesired contributions due to, but not limited to, changes in ambient fluid speed and changes in altitude of the sensing device. The undesired contributions are attenuated using an adaptive filter with the measurements of the change in ambient fluid speed and the change in altitude. This approach differs from existing applications of adaptive filtering in that the invention uses measurements of speed and displacement to improve a pressure measurement. This approach differs from existing methods for attenuating the affects of the wind on the measurement of infrasound in that it does not require the use of a large spatial averaging filter.

Abstract: An optical detector device for a counter, comprising a consumption indicator, formed from a rotating disc (4) with a section called active (4A) and optical elements of the receiver and emitter types opposite the disc. The received signal from which is used to infer the number of rotations of the disc and which comprises at least two of the optical elements (6A, 6B) of one type and at least one of the optical elements (7) of the other type. The section (4A) is a reflecting section with a center angle of 45 to 225 DEG and the two optical elements of one type (6A, 6B) are emitting elements, emitting a beam of light, where the lines connecting each trace (S(6A), S(6B)) of the beams on the disc (4) to the center of the disc form an angle at the center which is not zero.

Abstract: An apparatus for measuring at least one parameter associated with a fluid flowing within a pipe comprises an optical measurement device and a signal processor. The optical measurement device provides output signals indicative of unsteady pressures within the fluid at two or more axial locations along the pipe in response to light reflected from an outer surface of the pipe. The signal processor provides an output signal indicative of at least one parameter associated with the fluid in response to the output signals. The optical measurement device may include, for example, an electronic speckle pattern interferometer, a Fabry-Perot device, and/or a laser vibrometer. The at least one parameter may include at least one of: density of the fluid, volumetric flow rate of the fluid, mass flow rate of the fluid, composition of the fluid, entrained air in the fluid, consistency of the fluid, size of particles in the fluid, and health of a device causing the unsteady pressures to be generated in the pipe.

Abstract: The invention concerns solid-state gyrolasers used to measure rotation speeds or relative angular positions. This type of equipment is used, in particular, in aeronautical applications. The purpose of the invention is to complete the optic devices required to control the instability of ring-shaped solid-state lasers using specific optic devices that eliminate the blind region without adding a measurement bias. In this way, a “fully optic” solid-state laser is obtained, without moving parts, stable, and without blind region. These devices comprise in particular polarization separation optical devices, reciprocal and nonreciprocal optical rotators arranged so that four linearly polarized optical modes travel in the cavity at sufficiently different frequencies to avoid mode locking.

Abstract: A system for measuring flow information of a fluid, the system includes a light emission control unit for passing an X-ray through a specimen only at desired moments; a scintillator installed on an axis of a beam to convert an X-ray wavelength flow image, which is generated while the X-ray passes through the specimen, into a visible wavelength flow image; and a recording device for acquiring a flow image focused on the scintillator. The system may further include a synchronization unit for synchronizing the recording device with the light emission control unit to acquire two or more flow images at a predetermined interval using the recording device; and a PIV velocity field measurement unit for extracting quantitative flow information from the two or more flow images acquired by the recording device.

Abstract: A vehicle external recognition system is provided with: a relative position detecting section detecting an object ahead of a vehicle as a detected object to detect a relative position relationship between the detected object and the vehicle, a relative velocity calculating section calculating a relative velocity between the detected object and the vehicle based on the relative position relationship detected by the relative position detecting section by using an initial value that is preset, a vehicle velocity detecting section detecting a velocity of the vehicle, and a motion attribute discriminating section discriminating a motion attribute, indicative of a motion state of the detected object, based on the relative velocity calculated by the relative velocity calculating section and the velocity detected by the vehicle velocity detecting section.

Abstract: A coherent laser radar device is described which comprises a laser source (11), and two or more transceivers (84) are optically connected to the laser source by optical fiber cables (42, 48, 82) that are routed through an optical routing means (80). A detection means (27) is also provided, and radiation received by the two or more receivers (84) can also be optically coupled to the detection means (27) by optical fiber cables (82, 86, 90).

Abstract: The invention relates to an interferometer arrangement (1000) having at least one measuring beam path for providing light in an object area, at least one reference beam path and at least one unit for superposing light of the measuring beam path with light of the reference beam path and a unit for detecting an interference phenomenon caused by light from the object area and light from the reference beam path. The invention further relates to a method for measuring the velocity of an object with an interferometer arrangement. In the interferometer arrangement, the unit for detecting has a spatial resolution which corresponds to the characteristic spatial period of the interference phenomenon. In evaluating the time change of the interference signal, the movement of stray centers can be measured. Use of such an interferometer arrangement in a surgical microscope allows to visualize areas of a field of surgery which cannot be accessed with light in the visible spectrum.

Abstract: A laser radar apparatus includes a mixer 12 for converting the frequency of an electric signal outputted from a photodetector 11 into a baseband frequency by using a modulating signal generated by an oscillator 2. The laser radar apparatus carries out a coherent integral of the electric signal whose frequency has been converted by the mixer 12, and measures the quality of scatterers which exist in the atmosphere from a result of the integral. As a result, even when the S/N ratio of the light signal received by a receiving optical unit 8 is low, the laser radar apparatus can detect the quality of the scatterers.

Abstract: A laser Doppler velocimeter is formed using erbium-doped fiber as the lasing medium. The fiber is diode-pumped. By properly modulating the lasing in the fiber, pulses of radiation may be generated. A telescope acts as the transmission device to focus the radiation at a specified point, and may also act as the receiving system for reflected radiation. The portion of the reflected radiation collected by the receiving system is analyzed to determine the Doppler shift caused by aerosols or objects at the focal point of the telescope.

Abstract: A system for measuring velocity of a target is disclosed. In one embodiment, the system includes a laser device, a detector and a signal processor. The laser device produces a frequency-modulated laser beam, wherein the frequency-modulated beam is split into at least two laser beams, wherein a reflected beam comprising one split beam is directed to the target and reflected from the target. The detector detects a combination of the reflected beam and a reference beam comprising another split beam, wherein the reflected beam and the reference beam have unequal delays. The signal processor obtains velocity information from the combined beam by use of Doppler-shifted harmonics of the modulation frequency.

Abstract: A first luminous flux emitted from the front end face of a LD is reflected by a mirror to be made incident on a detection point on the surface of a measuring object, and a second luminous flux emitted from the rear end face of the LD is reflected by another mirror to be made incident on the detection point. Scattered light from the first detection point is received in a photodiode. A signal processing circuit part calculates the frequency shift quantity of the scattered light based on output from the photodiode. As a result, a velocimeter is provided which detects the moving speed of a measuring object highly precisely.

Abstract: An illuminator (e.g., laser) produces a light beam that partially passes through, and is partially blocked by, a mask contrastingly patterned via non-transparent and transparent portions. The mask-conformed light passes through a lens so that the mask's pattern is projected into fluid seeded with a luminescent substance, which illuminatively reveals an image of the mask's pattern. The light beam can also be expanded and/or diffused prior to reaching the mask. Instead of or in addition to transmissive properties, the mask can have reflective properties wherein the illuminator-produced light beam partially bounces off of, and is partially absorbed by, a mask contrastingly patterned via non-reflective and reflective portions. Reflective optics can supplement or replace refractive optics for projecting the mask's pattern into the fluid.

Abstract: A compact computer-controlled fully-packaged apparatus providing reliable multi-dimensional characterization of spherical objects in a field environment is disclosed. The apparatus has a rugged, free-space, integrated optical system with up to three lasers that generate at a laser-specific wavelength the coherent light with substantially high pointing stability. The apparatus also has a receiver. Each laser generates a pair of beams crossing each other at a predetermined laser specific angle to form a sample volume such that beams from all lasers coincide in the same spot. The receiver has photodetectors to sense the light scattered from a spherical object. Three photodetectors measure a size and one of the three photodetectors measures a first velocity component, a fourth photodetector measures a second velocity component, and a fifth photodetector measures a third velocity component of the spherical object. The velocity components are orthogonal to each other.