Abstract: An acoustic transducer system for acoustic signals in water has at least one hollow spherically-shaped shell for vibrating in response to acoustic signals impinging from the water. The hollow spherically-shaped shell has one or more portions that are reflective of impinging radiation, and a resilient matrix in contact with the water resiliently supports the responsive hollow shell. A laser Doppler velocimeter transmits radiation onto the reflective portion (portions) and receives reflected radiation from the reflective portion (portions). The reflected radiation generates signals in the laser Doppler velocimeter that are representative of the acoustic signals from the water medium. A computer receives the representative signals from the laser Doppler velocimeter and displays them on an interconnected display to determine direction and range to a target. The acoustic signals can originate from the target or can be reflected portions of acoustic energy transmitted from an acoustic projector.

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 from an optical head into an atmosphere. Light from the at least one second beam of light scattered by molecules or aerosols in the atmosphere is collected by a corresponding at least one telescope of the optical head as at least one light signal. The at least one light signal and the reference beam are simultaneously processed by different portions of a Fabry-Pérot 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: An optical profile determining apparatus includes an optical detector and an optical source. The optical source generates a transmit beam including a plurality of wavelengths, and generates a reference beam including the plurality of wavelengths. Optical elements direct the transmit beam to a target, direct a resulting reflected transmit beam back from the target to the optical detector, and combine the reference beam with the reflected transmit beam so that a profile of the target is based upon fringe contrast produced by the plurality of wavelengths in the reference beam and the plurality of wavelengths in the reflected transmit beam.

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: The invention relates to a system for measuring velocity. In one embodiment, the system includes a laser assembly having a laser diode and a power detection diode. The laser diode emits a plurality of laser signals which are frequency-modulated, wherein a selected one of the frequency-modulated signals is directed to and reflected from a target, and wherein another selected one of the frequency-modulated laser signals transmitted via one signal path is combined with the reflected laser signal transmitted via another delayed signal path in the interior of the laser assembly. The power detection diode detects the combined signal. The system also includes a signal processor configured to obtain velocity information from the detected signal by use of the harmonic frequencies associated with the modulation frequency.

Abstract: Two different phase components obtained by splitting interference light of light from an object by a diffraction grating are guided to first and second PD's by a second optical system. A first signal is outputted from a first signal processing circuit section that receives light reception signal from first PD, and a second signal is outputted from a second signal processing circuit section that receives a light reception signal from the second PD. A third signal of an interference light signal whose noise component is removed is outputted by a third signal processing circuit section using the first signal and the second signal. Then, the frequency of the third signal is detected, and the movement velocity of the object is detected by a movement velocity detection section on the basis of the frequency.

Abstract: The flow meter is a device having a laser Doppler anemometer (LDA) which measures the instantaneous center line velocity of fluid flow in a pipe and processes the instantaneous velocity so obtained to compute the volumetric flow rate, mass rate, and other flow characteristics as instantaneous quantities and/or integrated over a time interval using an electronic processing method which provides an exact solution to the Navier-Stokes equations for any periodically oscillating flow. The flow meter is particularly adapted for measuring the flow characteristics of high pressure automotive fuel injection systems. Three embodiments of the flow meter are described, including a stationary stand for off-line bench testing flow rate in a fuel injection system, a portable flow meter for inline testing in a vehicle's fuel line, and an on-board flow meter sensor connected to an engine control module.

Abstract: When utilized in a flow imaging instrument, calibration beads provide a known data source that can be employed in various self-diagnostic, calibration and quality metric applications for the both the optical system of the flow imaging instrument, as well as the flow cell of the flow imaging instrument. Such data can be used to determine point spread functions associated with an imaging system, to determine a sensitivity of an imaging system, and to determine a focal point of the imaging system. Imagery collected from calibration beads can be used to determine core size and stability and TDI/flow speed synchronization. Calibration beads can be beneficially employed to enable stable system operation, even when very low sample concentration, or very small sample sizes are to be analyzed.

Abstract: The invention relates to a system for measuring velocity. In one aspect of the invention, the system comprises a laser emitting device, an optics assembly, a combiner and a signal processor. The laser emitting device generates a frequency-modulated laser signal. The optics assembly splits the frequency modulated signal into a plurality of laser signals, and directs the split signals to a target and receives at least one signal reflected from the target. The combiner receives one of the split signals transmitted via one signal path and the at least one reflected signal transmitted via another signal path, and multiplies the received signals. The signal processor extracts velocity information from the multiplied signal.

Abstract: Various embodiments of the present invention provide a flow meter device having a laser Doppler anemometer (LDA) which measures the instantaneous center line velocity of fluid flow in a pipe. The flow meter may process the instantaneous velocity so obtained to compute the volumetric flow rate, mass rate, and/or other flow characteristics (e.g., as instantaneous quantities and/or integrated over a time interval) The flow meter may use an electronic processing method. The electronic processing method may provide essentially an exact solution to the Navier-Stokes equations for any periodically oscillating flow.

Abstract: A system for tuning one or more second radiant sources relative to a first radiant source may include a coupler configured to combine output signals from the first radiant source and a second radiant source to generate a heterodyne signal containing a frequency difference between the output signals from the first radiant source and the second radiant source. A photodetector may be configured to convert the heterodyne signal into an electrical signal containing the frequency difference. A spectrum analyzer may be configured to measure the frequency difference in the electrical signal and generate a precise difference value. A controller may be configured to adjust a wavelength of the second radiant source relative to that of the first radiant source based on the precise difference value. Laser spectroscopy may be performed by passing the output signals from the first radiant source and the second radiant source through a sample volume and detecting reflected or emitted radiation.

Abstract: The invention provides a method and system for adjusting vehicle speed, beginning with a modulated laser pulse being emitted. A reference portion of the emitted modulated laser pulse is extracted, a reflected portion of the emitted modulated laser pulse is received, and the reflected portion is combined with the reference portion on a portion of an imaging array. A determination of a relative velocity is based on the combined reflected portion and reference portion.

Abstract: The present invention relates to an apparatus for use in the determination of a condition or state of an object based on quasi-elastic interaction between the object and light transmitted to the object, the apparatus comprising a beam splitter arrangement for splitting an incoming light beam of wavelength, ?, into a diffracted light beam and an undiffracted light beam, the beam splitter arrangement comprising a first and a second diffractive member, the first diffractive member transforming the light beam emitted by the light source into the diffracted and the undiffracted light beams, the second diffractive member receiving the diffracted light beam and diffracting the received light beam in a direction substantially parallel to the undiffracted light beam from the first diffractive member, wherein the diffracted light beam, after being diffracted by the second diffractive member, and the undiffracted light beam from the first diffractive member are separated by a distance, d, said distance, d, being depende

Abstract: An Airborne Windshear Detection System measures wind during the Take off and Landing phase by determining the Doppler Shift of backscattered radiation that is transmitted by an on-board laser system. The collected, scattered light is mixed with a sample from the transmitting Laser using a Dual Differential Mach-Zehnder Interferometer technique. The resulting frequency shift determines the presence of dangerous windshear in the anticipated trajectory of the aircraft.

Abstract: The present invention relates to an apparatus for the determination of a condition or state of an object based on quasi-elastic interaction between the object and light transmitted to the object, the apparatus comprising a diffractive optical element having a diffracting region comprising a first diffracting structure for diffraction and focussing of a first light beam to the object, and a second diffracting structure that is laterally displaced relative to the first diffracting structure for diffraction and focussing of a second light beam to the object. The first and second diffracting structures focus the first and second light beams in the same focussing plane, the focussing plane being substantially perpendicular to propagation directions of the first and second light beams. The diffracting region further comprises a receiving diffracting structure for diffraction of light from the light beams that has interacted with the object. The diffracted light is diffracted in a diffraction angle.

Abstract: The present invention relates to a laser anemometer making it possible to determine the relative velocity between the anemometer and an ambient medium. The architecture of the anemometer includes a laser source, emission and reception optics for focusing a laser beam onto a measurement zone containing particles in suspension in the ambient medium and for receiving the radiation back-scattered by the particles. It also includes an optical mixer for mixing the received radiation and reference radiation representing the radiation emitted by the source, and a detector at the output of the mixer. The relative velocity between the anemometer and the ambient medium is determined by computation on the basis of the Doppler effect generated by the radiation and detected by the detector. The laser source is located remotely from a common support which carries the optical emission and reception system as well as the mixer. It is connected to this common support by at least one optical fiber.

Abstract: A high range resolution ladar includes a chirp generator for producing a chirp signal waveform that is used by a laser diode to propagate a divergent laser light waveform. The reflected light signals from the target are directed to a self mixing detector that is coupled to the chirp generator where the responsivity of the detector varies in accordance with the chirp waveform for converting reflected light signals from the target to electrical signals and for mixing the converted electrical signal with the chirp waveform to produce an output electrical signal whose frequency is proportional to the range to the target. The self-mixing detector includes at least one detector having a semiconductor substrate and first and second electrodes deposited on the substrate and spaced from each other, wherein the first set of electrodes is connected to the chirp generator and the second set of electrodes is connected to a memory for storing a plurality of frames of image data.

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: A laser transponder for disabling a laser-based speed monitor which is transmitting a monitor laser beam at a moving vehicle by transmitting a jamming laser beam to the laser-based speed monitor. The monitor laser beam is in the shape of a monitor signal that includes monitor pulse trains emitted at a first frequency, while the jamming laser beam is in the shape of a jamming signal that includes jamming pulse trains emitted at a second frequency.

Abstract: A method and an apparatus for optical inertial measurement includes a body with an optical head mounted on the body. The optical head has at least one optical element creating an optical path to at least one viewing region. A sensor is in communication with the at least one optical element and adapted to receive images of the at least one viewing region. A processor is provided which is adapted to receive signals from the sensor and perform optical flow motion extraction of the at least one viewing region. The speed and direction of movement of the body and the orientation of the body in terms of pitch, roll and yaw being determined by monitoring the rate and direction of movement of pixel shift within the at least one viewing region, sequentially comparing consecutive images and calculating attitude.

Abstract: Apparatus for detecting the oscillation amplitude of an oscillating object (3) includes an optical radiation source (9) and a detector (10) including first and second optical radiation sensing areas (24A, 24B) adjacent each other. The detector (10) and the optical radiation source (9) are adapted to be located opposite each other with the oscillating object (3) located between the source (9) and the detector (10) so that the object (3) blocks a portion of the sensing areas (24A, 24B) from receiving optical radiation from the source (9). A processor (18) coupled to the detector (10) receives first and second output signals representing the magnitude of optical radiation sensed by the first and second optical radiation sensing areas (24A, 24B), respectively. The processor (18) processes the first and second output signals to obtain an indication of the amplitude of oscillation of the object (3).

Abstract: A fluorescent or luminescence image of at least part of a biological sample is imaged, then a transmission light image of at least part of the biological sample is imaged, and thereafter the fluorescent or luminescence image and the transmission light image are overlaid such that the identical area of the sample is coincided to display. The present invention allows detecting the accurate location of fluorescence or luminescence in a given part of the biological sample.

Abstract: The swirl injector for an internal combustion engine is an electronic fuel injector for a direct injection engine, either gasoline or diesel. The injector has a housing defining a fluid channel, a needle valve disposed in the fluid channel with a spring biasing the valve to a closed position, and a solenoid disposed in the housing encircling the fluid channel. The injector has a nozzle with a conical valve seat and a cylindrical discharge orifice. The needle tip is ball shaped, and the needle body has a plurality of helical grooves which are rectangular in cross section having a width to depth ratio of 1.5:1 at about a 46° angle adjacent the tip. The valve lift is 50 &mgr;m in 60 &mgr;s. The penetration, swirl speed, and pitch angle are controllable through the injection pressure, providing an enhanced fuel injector for dual mode fuel injection.

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: When utilized in a flow imaging instrument, calibration beads provide a known data source that can be employed in various self-diagnostic, calibration and quality metric applications for the both the optical system of the flow imaging instrument, as well as the flow cell of the flow imaging instrument. Such data can be used to determine point spread functions associated with an imaging system, to determine a sensitivity of an imaging system, and to determine a focal point of the imaging system. Imagery collected from calibration beads can be used to determine core size and stability and TDI/flow speed synchronization. Calibration beads can be beneficially employed to enable stable system operation, even when very low sample concentration, or very small sample sizes are to be analyzed.

Abstract: A stand-alone speedometer includes an electromagnetic wave source, a beam splitter, a detector and two media with different dispersive dragging effects. An electromagnetic wave is divided into two beams by the beam splitter. The two beams pass the two media differently and they combine again to go on to a detector, giving rise to interference which records the travel-time difference between two beams. Because the two media have different dispersive dragging effects on the propagation of the electromagnetic wave, measuring the change of the travel-time difference when the apparatus is stationary to that when the apparatus is moving will give the translational speed of the apparatus.

Abstract: Apparatus for detecting hazardous materials is mounted on an aircraft and has a sensor, a heading unit, a transceiver and a GPS unit. The sensor has an airfoil shaped probe and an electronics module. The probe has a positive airflow, enclosed sensing chamber with a hazardous material sensing element. The system for detecting hazardous materials includes aircraft with the hazardous material detecting apparatus and a ground network. The method for detecting hazardous materials includes the steps of providing aircraft with hazardous material sensing apparatus and a ground network, collecting hazardous material and atmospheric data with the sensing apparatus, transmitting the position, wind velocity and hazardous material data to the ground network, calculating distribution of hazardous materials in the atmosphere, generating a real-time map of distribution of hazardous materials and predicting dispersion of the hazardous materials in the atmosphere.

Abstract: When utilized in a flow imaging instrument, calibration beads provide a known data source that can be employed in various self-diagnostic, calibration and quality metric applications for the both the optical system of the flow imaging instrument, as well as the flow cell of the flow imaging instrument. Such data can be used to determine point spread functions associated with an imaging system, to determine a sensitivity of an imaging system, and to determine a focal point of the imaging system. Imagery collected from calibration beads can be used to determine core size and stability and TDI/flow speed synchronization. Calibration beads can be beneficially employed to enable stable system operation, even when very low sample concentration, or very small sample sizes are to be analyzed.

Abstract: The disclosed invention concept utilizes a homodyne/heterodyne interferometer technique in a modified lidar in such a manner as to sense the rotational velocity magnitude and sense of a rotating (or “spinning”) object. Sensing is accomplished in assessing either the Doppler bandwidth of a single axis system. or in sensing the frequency separation of Doppler spectrums in a “two” axis system. The technique is unique in that the Doppler bandwidth is linearly proportional to rotational velocity and independent of intercept position in the rotation plane. The technique as disclosed is based on optical fiber lidar techniques, but can be implemented in free-space optics as well. The disclosed invention therefore comprises both a technique for utilization of an optical fiber lidar and a new arrangement of lidar elements. Compact and cost effective, standoff rotation velocity sensors and systems can be fabricated with this technique.

Abstract: The present invention provides a system and method for collecting data from a Laser Doppler Anemometer of the type including a probe mounted to a controllable traversing system. Velocity and position data is collected from the probe while it is continuously in motion, and displayed in real time. If at any point the data is of unacceptable quality, the data collection process is stopped, the probe is moved to a last known good position, and the data collection process is restarted.

Abstract: An optical endoscopic fluid flow measurement probe assembly is disclosed having a user end and a distal end. The distal end having a light sheet generator and at least one reflected light acquirer, and the endoscope is provided with transmission means to transmit information away from the distal end. The light sheet generator is adapted in use to generate a sheet of light and the light acquirer being adapted to image light reflected from the light sheet, the light sheet generator and light acquirer being provided in the same endoscope.

Abstract: The invention relates to a system for measuring velocity. In one aspect of the invention, the system comprises a laser emitting device, an optics assembly, a combiner and a signal processor. The laser emitting device generates a frequency-modulated laser signal. The optics assembly splits the frequency modulated signal into a plurality of laser signals, and directs the split signals to a target and receives at least one signal reflected from the target. The combiner receives one of the split signals transmitted via one signal path and the at least one reflected signal transmitted via another signal path, and multiplies the received signals. The signal processor extracts velocity information from the multiplied signal.

Abstract: The invention relates to a method for controlling a PMD system which is characterized by controlling a photoelectronic mixing device (PMD) by at least one modulation signal (Umod) and one modulation signal (Umod) that is complementary thereto. A transmitter (E) emits electromagnetic radiation that is intensity-modulated by means of the at least one modulation signal (Umod). The inventive method is further characterized by varying the modulation signal (Umod) between at least two modulation frequencies (f1,f2,fi).

Abstract: A method and system for automatic recognition and classification of a vibrating target among members of a plurality of objects having their vibration spectra stored in a database. In deciding as to which member of an alleged couple of vibrating objects the target should be assigned, the method uses an algorithm of signal processing which is based on wavelet packet analysis to predict a-priory a bandwidth in which the differences between the vibration of the spectrum is mostly pronounced, and the resolution within the bandwidth which is adequate to enable the decision.

Abstract: A flow monitor that is purely optical and non-invasive and does not possess any significant obstruction to the flow. It creates no significant pressure drop and no pulsed pressure waves in the patient's airway and can be placed close to the patient, it is not sensitive to gas composition and contamination, it is easy to clean, because it uses a disposable or reusable flow measurement cuvette, and it is more accurate, rugged and reliable than existing sensors on the market. Fluid flow is determined by optically monitoring the time of travel of a disturbance in the fluid flow. In one embodiment, the disturbance is caused by heating the fluid and in another embodiment, the disturbance in air flow is caused by injecting minute drops of water into the flowing air.

Abstract: Doppler sensor apparatus has means outputting coherent electromagnetic radiation (2), means (4) for transmitting radiation from the source means (2) to a point in space, means (6) for receiving radiation reflected from the point in space and means (8) for determining any Doppler shift in the reflected radiation. The transmitting means (2) and the receiving means (4) are separate, and the transmitting means (2) and the receiving means (4) are each adapted to have radiation guiding means (26, 28) releasably attached thereto, thereby enabling radiation guiding means (26, 28) for routing radiation from the source means (2) to the transmitting means (4) and from the receiving means to the determining means (8) to be interchanged with radiation guiding means (34, 36) for routing radiation for use in aligning the transmitting means (4) and the receiving means (6) to the transmitting means (4) and to the receiving means (6).

Abstract: An optical input device for an apparatus generates input signals by moving the device and an object (15) relative to each other and measures the movement by the effects of self-mixing in a diode laser (3, 5) and Doppler shift caused by the movement. For each measuring axis (X, Y, Z), radiation from a diode laser (3, 5) is converged on a window (12) across which the object (15) moves. Part of the radiation scattered by the object, whose frequency is Doppler-shifted due to the movement, re-enters the laser cavity (20) and causes a change in cavity properties. By measuring such a change, for example, by a photo diode, information about the movement is obtained. As the input device is small and cheap, it can be used in a number of different consumer apparatus.

Abstract: The present invention relates to a laser anemometer making it possible to determine the relative velocity between the anemometer and an ambient medium.

Abstract: A laser radar system is disclosed. The laser radar system includes a transmitting means that transmits a signal. The transmitted signal is formed by an optical signal that is amplitude modulated with a source signal thereby forming a transmitted signal having light packets at a repetition rate of the source signal. A receiving means that receives the transmitted signal after it is reflected from an object. A Doppler processor determines the Doppler frequency shift of the source signal from signals derived from the reflected signal.

Abstract: An optical flow monitor. Fluid flow is determined by correlating two interference signals produced by coherent laser beams passing through a flowing fluid at two spaced-apart paths. The distance between the two paths is known and the correlation of the two signals is used to determine the time required for the fluid to flow between the two paths. In a preferred embodiment actually built and tested by Applicant the correlation is made by having an operator monitor on an oscilloscope the intensities of interference fringes corresponding to each of the two beam paths. Intensity variations in the interference fringes are caused by the same turbulent eddies passing each of the two paths. These turbulent eddies cause fluctuations in the index of refraction of the fluid which produce similar patterns on the oscilloscope which are separated on the oscilloscope time scale by an amount corresponding to the distance between the two beam paths and the flow rate of the fluid.

Abstract: The present invention relates to a process for monitoring the flow rate of a fluid stream which comprises heating the stream with a heating member for a time sufficient to induce a change in the refractive index of the fluid; detecting the change in the refractive index of the fluid at a location remote from the heating member; and calculating the flow rate of the fluid from the change in the refractive index.

Abstract: A distributed laser based obstacle awareness system for use on-board an aircraft comprises: a plurality of obstacle detecting sensors disposable at a corresponding plurality of locations of the aircraft for emitting laser energy from the aircraft into a predetermined region of space and for receiving return laser energy from an obstacle in the predetermined region of space; a laser source for emitting a laser beam along an optical path; and a plurality of bistatic optical channels. Each channel comprises a plurality of transmission fiber optic cables and at least one receiver fiber optic cable and extends from the laser source to a corresponding obstacle detecting sensor of the plurality to direct the laser beam from the optical path to its corresponding obstacle detecting sensor of the plurality for emission into the corresponding predetermined region of space; and a light detector.

Abstract: An optical flow monitor. Fluid flow is determined by correlating two interference signals produced by coherent laser beams passing through a flowing fluid at two spaced-apart paths. The distance between the two paths is known and the correlation of the two signals is used to determine the time required for the fluid to flow between the two paths. In a preferred embodiment actually built and tested by Applicant the correlation is made by having an operator monitor on an oscilloscope the intensities of interference fringes corresponding to each of the two beam paths. Intensity variations in the interference fringes are caused by the same turbulent eddies passing each of the two paths. These turbulent eddies cause fluctuations in the index of refraction of the fluid which produce similar patterns on the oscilloscope which are separated on the oscilloscope time scale by an amount corresponding to the distance between the two beam paths and the flow rate of the fluid.

Abstract: A miniature laser Doppler probe includes a laser, lens, another lens with a diffraction grating etched thereon, and a focusing lens. The focusing lens focuses the diffraction grating on an interrogation volume which has the particles whose movement is to be detected.

Abstract: An evanescent filed based sensor uses a detector for sensing variations in properties of a fluid flowing in a boundary layer adjacent to the detector. The detector comprises an optical waveguide in the form of an optical fiber having a core layer covered by a cladding layer and having a substantially D-shaped cross section defining a planar surface with an optical grating pattern thereon. When a beam of laser light is directed through the detector as an input, variations in an output of the beam of laser light are indicative of changes in fluid pressure or density in the boundary layer or immediate region adjacent to the grating of the optical waveguide.

Abstract: A laser transponder for disabling a laser-based speed monitor which is transmitting a monitor laser beam at a moving vehicle by transmitting a jamming laser beam to the laser-based speed monitor. The monitor laser beam is in the shape of a monitor signal that includes monitor pulse trains emitted at a first frequency, while the jamming laser beam is in the shape of a jamming signal that includes jamming pulse trains emitted at a second frequency.

Abstract: A constellation of satellites comprising at least two satellites in the same orbit is used to measure atmospheric wind speeds by means of a spatial wind lidar; each satellite carries a Doppler lidar, with a fixed sight axis. The orbit is a polar or quasi-polar orbit, with an orbital altitude from 350 to 500 km. The sight angles and the distribution of the satellites in the orbit are chosen so that the tracks on the surface of the Earth of the sight axes of the satellites of the constellation are substantially coincident over half of the surface of the Earth and regularly distributed over the other half of the surface of the Earth.

Abstract: A water monitoring system for a nuclear reactor is provided. In an exemplary embodiment, the water monitoring system includes a fiber optic cable having a first end and a second end, with the first end configured to optically couple to the reactor cooling water distribution system, and at least one laser light source optically coupled to the second end of the fiber optic cable. The water monitoring system also includes a spectrophotometer optically coupled to the second end of the fiber optic cable.

Abstract: The disclosed invention concept utilizes a homodyne/heterodyne interferometer technique in a modified lidar in such a manner as to sense the rotational velocity magnitude and sense of a rotating (or “spinning”) object. Sensing is accomplished in assessing either the Doppler bandwidth of a single axis system or in sensing the frequency separation of Doppler spectrums in a “two” axis system. The technique is unique in that the Doppler bandwidth is linearly proportional to rotational velocity and independent of intercept position in the rotation plane. The technique as disclosed is based on optical fiber lidar techniques, but can be implemented in free-space optics as well. The disclosed invention therefore comprises both a technique for utilization of an optical fiber lidar and a new arrangement of lidar elements. Compact and cost effective, standoff rotation velocity sensors and systems can be fabricated with this technique.

Abstract: An apparatus for determining the rotational speed of an object returning diffuse reflections where no reflective singularity exists on the object or no clearly distinct light pulse is produced. A light source illuminates a target area on the object. An optical system receives the reflected light, selectively filters by wavelength, and focuses the light on a detector for signal processing. The reflected light signals may be a series of complex patterns that repeat once per revolution. A Fourier Transform with additional processing enhancements is performed on the signals and used as a basis to calculate the speed of the object The signal processing may be automated, resulting in a speed (RPM) solution being displayed for the operator of the device.