Abstract: A method and apparatus for measuring liquid flow, particularly milk, includes directing the liquid to flow through one or more flow channels, while exposing the liquid to electromagnetic radiation; measuring the transparency to electromagnetic radiation of the liquid flowing through the flow channel; and measuring the momentary attenuation of electromagnetic radiation by the liquid flowing through the flow channels, to determine the momentary volume of the liquid flowing through the flow channel. The momentary velocity of the liquid flowing through the flow channels is also determined, thereby permitting a determination of the momentary flow rate of the liquid flowing through the flow channels.

Abstract: A sensor assembly to be carried on an aircraft or spacecraft which will travel along an arbitrary flight path, for providing an image of terrain over which the craft travels. The assembly includes a main linear sensor array and a plurality of auxiliary sensor arrays oriented parallel to, and at respectively different distances from, the main array. By comparing the image signals produced by the main sensor array with those produced by each auxiliary array, information relating to variations in velocity of the craft carrying the assembly can be obtained. The signals from each auxiliary array will provide information relating to a respectively different frequency range.

Abstract: First and second relatively high power laser beams are directed into a volume enclosing a flow field of molecules of a molecular species. The beams are focussed to form an overlapping region of the beams in the flow field, for tagging a portion of the associated molecules by driving them into their first vibrational state by stimulated Raman pumping. A high intensity beam of light is directed into the flow field proximate the overlap region for intercepting the tagged molecules, and causing them to fluoresce, thereby permitting their displacement to be measured through observation thereof, for determining the velocity of the associated molecules and flow field.

Abstract: A speed sensor for a moving vehicle. A transmissive grating is used in conjunction with an electromagnetic wave source and beam combining waveguide to mix two beams of frequency f and f+.DELTA.f, where .DELTA.f is proportional to the speed of the grating relative to the ground. The source energy is reflected off the road to the grating. The zeroth and first order transmission from the grating are mixed to give the beat frequency .DELTA.f proportional to the ground speed. The sensor has no moving parts, and is independent of any gear ratios.

Abstract: At least a set of two spatial filters are so arranged in a two-dimensional space or three-dimensional space that their spatial distributions are opposite to each other. Two systems of light detection signals from a moving object are synchronously collected through the spatial filters, integrated, and photoelectrically converted into time-series electrical signals. The electric signals are processed according to a predetermined algorithm. A result of the process is judged as positive or negative to find the direction of a velocity of the object. The magnitude of the velocity is found from the two systems of light detection signals according to a known equation. Instead of oppositely arranging the spatial distributions of the two spatial filters, at least one differential spatial filter system may be employed to provide light detection signals corresponding to those provided by the oppositely arranged spatial filters.

Abstract: A laser Doppler velocimeter for near-wall measurements which includes at least one beam-turning device. The beam-turning device receives laser light, reflects and redirects the light at various angles in order to obtain measurements for all three velocity components at grazing incident angles. The beam-turning device includes a mirror or prism at one end which reflects the received light in a particular direction. A collector lens receives the particle scattered light from which the relevant velocity components are determined. The beam-turning device can also be a miniature fiber optic head which outputs laser light and can be turned in any direction.

Abstract: A remote object/vehicle identification and speed determination system including a bar code label on each object/vehicle and a device for continuously scanning an area to determine when the object/vehicle is present at a predetermined distance from the scanning device. The scanning device may be responsive to ambient visible or invisible radiation from the label. Each label includes unique identification data for the object/vehicle as well as spaced framing signals used for making distance determinations. Each label may be invisible and may be on or in the windshield of a vehicle.The signals from the scanning device are sampled continuously and the sampled signals are stepped along a shift register. Parallel outputs from the shift register are continuously analyzed so that signals from a single scan across a label are sufficient to determine if an object/vehicle is at a predetermined distance from the scanning device and to read the unique identification data.

Abstract: An apparatus is provided for determining the velocity and orientation of a vehicle, for instance to permit route guidance by dead reckoning. Two optical speed over ground sensors on the vehicle are arranged at acute angles to the longitudinal axis of the vehicle. One or more further sensors, such as a fibre optic gyroscope or one or two optical speed over ground sensors, are provided on the vehicle. The speed and direction from these sensors can be used by a data processor to perform dead reckoning navigation and the vehicle position can thus be determined.

Abstract: A plurality of lasers, each regulated to operate at a particular temperature, are supported by a manifold to direct coherent light into space. The regulation may be provided by producing pulses of a trickle current of a particular magnitude through the laser, measuring the voltage required to produce the trickle current and adjusting the characteristics of a thermoelectric member in accordance with the magnitude of such voltage to adjust the rate at which the thermoelectric member transfers heat from the laser. The lasers produce substantially parallel and thin beams of light in pairs. The light beams in each pair provide an optimum angle for the interception by such paired beams of particles having individual trajectories in space. These particles scatter the light to a receiving lens system disposed within the manifold. The received light then passes through masks which restrict the collected light to a spatial pattern corresponding to the pattern of the light beams from the lasers.

Abstract: In a correlation-type speedometer which determines velocity by calculating stagger time from a maximum value of the correlation function of outputs from two sensors arranged one in front of the other in the direction of movement, use is made of an oblong slit, a sensor whose light-receiving surface has an oblong shape, a diaphragm having an oblong aperture, or lens that is cut leaving an oblong area through which light can pass. The result is formation of a measurement spot having an oblong shape that is narrow in a forward direction of movement and long in a direction at right angles to the forward direction. In another aspect, two sets of light sources and sensors are arranged so that their relative positional relationships are the same, the light sources are made to flash at different periods and the periodicity of the flashing light sources is utilized to eliminate the influence of light entering the sensor of one set from the light source of the other set.

Abstract: Described herein are an apparatus and range of techniques used to study the retinal vasculature near the fovea, a description of the need and rationale for noninvasive in vivo monitoring of the retinal vasculature, a presentation of theoretical and practical considerations which demonstrate that entoptic visualization of the smallest capillaries near the fovea is optimized by a small short wavelength source (1 mm or less) rotating at 3.5 Hz in a circular path (radius 2 mm) imaged in the plane of the eye's entrance pupil and a discussion of the feasibility of using these techniques as a reseResearch relating to the development of the present invention was supported in part by grants from the United States Department of Health and Human Services (NIH EY08005 and EY07638). The United States government may have corresponding rights to the license and use of any resulting patent.

Abstract: A clutter rejection filter for use in detecting moving targets which may be employed in a passive optical acquisition system. The filter comprises a plurality of detector elements which view an image scene. A plurality of transversal filters are individually coupled to the plurality of detector elements. Each of the transversal filters amplitude weight signals provided by the respective detector elements as a function of time, with each of the transversal filters having a predetermined impulse response. Summing circuitry is coupled to each of the transversal filters for combining the output signals provided thereby into a single output signal for the filter. The filter provides output signals which are maximized for objects traveling at a first velocity and minimized for objects traveling at a second velocity.

Abstract: Young's fringes are produced from a double exposure image of particles in a flowing fluid by passing laser light through the film and projecting the light onto a screen. A video camera receives the image from the screen and controls a spatial light modulator. The spatial modulator has a two dimensional array of cells the transmissiveness of which are controlled in relation to the brightness of the corresponding pixel of the video camera image of the screen. A collimated beam of laser light is passed through the spatial light modulator to produce a diffraction pattern which is focused onto another video camera, with the output of the camera being digitized and provided to a microcomputer. The diffraction pattern formed when the laser light is passed through the spatial light modulator and is focused to a point corresponds to the two dimensional Fourier transform of the Young's fringe pattern projected onto the screen. The data obtained froThis invention was made with U.S.

Abstract: A noninvasive pulsed fluorescence gas velocimeter that determines dynamic parameters of a gas flow from detection of fluorescent re-radiation of excited molecules of the gas. The present invention has higher altitude capability than devices that utilize particulate scattering. The velocimeter requires no probes and utilizes a laser or other light source that does not perturb the gas flow being measured.

Abstract: This optical velocimeter may be installed in an aircraft to measure the true airspeed and the angles of attack and of sideslip of the aircraft. Alternatively, the velocimeter may be mounted in a wind tunnel to measure the velocity of the airstream passing through the wind tunnel. In either case, the points of reference for measurement are the large number of aerosol particles that are entrained in the air and are assumed to have the same velocity as the oxygen and nitrogen molecules of the air itself.The velocimeter comprises a plurality of optical transmitters and optical receivers. Each transmitter includes a laser operated in the continuous-wave mode and a laser operated in the pulsed mode. The laser operated in the continuous-wave mode generates a "precursor light sheet" at some distance from the aircraft whose velocity is to be measured or in the wind-tunnel airstream whose velocity is to be measured.

Abstract: A time of flight velocimeter wherein a radiation source projects two parallel beams into an air mass. Each of the parallel beams converges into a waist portion. As an aerosol particle moves through the waist portion, part of the radiation of each of the beams is backscattered. This backscattered radiation is focused onto two detectors, one for each beam. Signals from the detectors, generated in response to the backscattered radiation, are processed to determine the velocity of the particle which has passed through the waist portion of the two beams.

Abstract: A system of double-pulse particle velocimetry, according to which small scattering particles are illuminated by two short pulses of laser light and then images are recorded photographically to produce a record from which the particle velocity can be determined by measuring the displacement of the particle images. Particle images is understood to mean both the non-overlapping individual particles and overlapping, coherently interfering images commonly referred to as "speckle". In order to resolve the directional ambiguity inherent in the system, artificial shifting is effected in the image field between exposures by an amount that is greater than any negative displacement occurring in the field, such shifting being performed here by means of an electro-optical device in place of the shifting previously produced by rotating mirrors and the like.

Abstract: Velocity is measured by observing velocity-related frequency shifts in light scattered from moving air molecules or particles suspended in moving air, by passing the scattered light through an absorption line filter window gas cell with a notch type attenuation profile as a function of frequency. The scattering region is illuminated with a narrow linewidth light source coincident in frequency with a strong absorption line of an absorption line filter, whereby light scattered from stationary air molecules or particles is passed into the filter and a portion of that light falling within the strongly attenuated region is absorbed. As the velocity of the molecules or particles in the scattering region increases, the scattering frequency is shifted due to the Doppler effect, and the portion of the scattered light falling beyond the filter cutoff increases, causing the intensity of the light transmitted through the filter increase.

Abstract: A velocity distribution measurement apparatus directs light at an object, detects scattered light from the object, photoelectrically converts the light and subjects it to signal processing to obtain velocity distribution characteristics of the object, by detecting a speckle pattern formed by interference between rays of light scattering from points on the object. The apparatus consists mainly of a laser beam source; an optical deflector for scanning the laser at a certain frequency; an optical system for projecting the light scanned by the deflector onto the object; a detector for detecting the speckle pattern; and signal processing means for analyzing detector outputs to establish the speckle pattern variations for each scanning frequency at which the optical deflector performs scanning, in order to obtain information on velocity distribution in the object. The optical system is easy to adjust, and measurement and processing can be accomplished in a relatively short time.

Abstract: Flow rates of multi-phase streams may be determined by use of a fiber optic probe which establishes an illuminated sensing zone of finite dimensions. The probe collects light backscattered from the zone, the collected light being converted by a photodiode to voltage waveforms. Flow rate is determined by sampling voltage waveforms at discrete points in time, the sample being digitized and the digits being autocorrelated for such discrete points.

Abstract: An apparatus detects the azimuth of the migration of groundwater containing suspended microscopic particles. The apparatus comprises a probe consisting of a light source which emits light in a vertical orientation and a photodigitizer which faces the light source and is separated from the light source to permit the flow of groundwater between the light source and the photodigitizer. When the probe is submerged in migrating groundwater, the eclipses of light created by the suspended microscopic particles as the groundwater passes between the light source and the photodigitizer are detected by the photodigitizer. Information from the photodigitizer is processed and then visually displayed.

Abstract: Novel methods and devices are provided involving at least one chamber, at least one capillary, and at least one reagent involved in a system providing for a detectable signal. As appropriate, the devices provide for measuring a sample, mixing the sample with reagents, defining a flow path, and reading the result. Of particular interest is the use of combinations of specific binding pair members which result in agglutination information, where the resulting agglutination particles may provide for changes in flow rate, light patterns of a flowing medium, or light absorption or scattering. A fabrication technique particularly suited for forming internal chambers in plastic devices is also described along with various control devices for use with the device.

Abstract: A speed measuring apparatus, for instance for measuring the speed of a vehicle over the ground, comprises a plurality of photodetectors arranged to view consecutive regions along parallel light paths. The photodetectors are arranged as two sets of alternating photodetectors whose combined outputs are subtracted to provide a signal whose frequency represents speed and is insensitive to height.

Abstract: An optical part for light transmission comprises a light conductor formed of a core of a transparent material and a clad of a material having a smaller refractive index than that of the core material, and a light emitting and/or receiving element, wherein the light emitting and/or receiving element is integrally combined with the core of the light conductor by a same material as the core material or by a material having a same refractive index as that of the core material and having a greater rigidity than that of the material forming the clad and/or jacket. The optical part can be used in a high temperature environment as well as a room temperature environment without involving any appreciable loss in light transmission.

Abstract: A three-dimensional laser Doppler velocimeter (10) has laser optics (12) for a first channel positioned to create a probe volume (18) in space, and laser optics (14) and (16) for second and third channels, respectively, positioned to create entirely overlapping probe volumes (20) in space. The probe volumes (18) and (20) overlap partially in space. Photodetector (22) is positioned to receive light scattered by a particle present in the probe volume (18), while photodetectors (24) and (26)are positioned to receive light scattered by a particle present in the probe volume (20). The photodetector (22) for the first channel is directly connected to provide a first channel analog signal (23) to frequency measuring circuits 28. The first channel is therefore a primary channel for the system.

Abstract: A method of measuring the flow velocity in wind tunnels is indicated, in which a path covered by particles located in a flow is employed as a measure of the flow velocity. In a pre-determined time interval, the particles are illuminated twice in a plane by means of a light, and a light reflected by the particles is recorded and transmitted in the form of an image. The image is transilluminated by a second coherent light beam focused in a first Fourier plane, and in this way a first Fourier-transformed image is produced, which is recorded in its turn. The image and the first Fourier-transformed image (23) are displayed immediately. The first Fourier-transformed image (23) is transilluminated by a third coherent light beam (19), and consequently a second Fourier-transformed image (34) is produced in a second Fourier plane (33) in an optical manner. The second Fourier-transformed image (34) is recorded and immediately further processed.

Abstract: Light equipment is provided for irradiating the measuring object and forming light spot on it through the collimate lens. Reflected light from the measuring object is incident to the spatial filter through the objective lens for detecting the incidence position of the reflected light. A distance measuring circuit calculates contiuously the distance (d) between the objective lens and the measuring object by optical triangulation based on the output signal from the spatial filter. The frequency detecting circuit is connected to the spatial filter. When the sought running speed is V, the pitch between each equivalent light receiving element p, and the magnification of the optical image of the measuring object M, the frequency detecting circuit measures the frequency f which is given by the formula of F=MV/p. The calculator calculates the velocity V based on the output signal from the distance measuring circuit and on the output signal from the frequency detecting circuit.

Abstract: A flow field seeded with small particles is illuminated by collimated, monochromatic laser light sheet 16. Doppler shifted scattering from particle motion is imaged by an optical system 22. An optical frequency-to-intensity converter 24 is located at the image plane such that the transmitted image contains a simultaneous two-dimensional measurement of flow velocity along a direction determined by a laser beam and observer (converter) direction. These images can be observed directly or through a TV-2-D array camera and monitor or processed through a computer system 28.

Abstract: There is provided a laser speckle velocity-measuring apparatus comprising: a semiconductor laser to irradiate the light to a moving object; first and second photo sensing devices whose light receiving points are arranged in the moving direction of the objects at a predetermined distance so as to be away from each other; a clock signal generating and control circuit for determining a clock frequency of the clock signal so that the number of clocks of the clock signal is always set to a constant value when the delay time of the photo sensing signal of the second photo sensing device for the photo sensing signal of the first photo sensing device is measured by the clock signals; and an arithmetic operating circuit for counting the clock signals and calculating the length, moving distance, or velocity of the object on the basis of the count value.

Abstract: Velocimeter comprises a measuring volume (100) in a particle-laden fluid stream, means for brightly illuminating the measuring volume and means for measuring, based upon the light scattered by said particles when they are illuminated, the velocity of the said fluid stream, having a mosaic of optical fibers (10) and at least one optical system (101) for projecting a plane of the measuring volume onto the mosaic's input plane, the mosaic's outputs being connected to the velocity measuring means.

Abstract: A laser doppler velocimeter system for wind shear detection comprising means for generating a beam of radiant energy, an optical system coupled to the beam for directing a first portion of the beam a predetermined distance to a scatterer of radiant energy, means coupled to the beam for conducting a second portion of the beam through a polarization preserving medium, the length of the medium substantially matching the predetermined distance, means for mixing the second portion of the beam with the radiant energy reflected by the scatterer and means coupled to the means for mixing for measuring a component of the velocity measurements of the scatterer. The velocity includes both horizontal and vertical components. The system may also be adapted for measurement of multiple predetermined distances by using multiple means for conducting a second portion of the beam, each of said multiple means having a length substantially matching one of the multiple predetermined distances.

Abstract: A velocimeter and a method for measuring the velocity of a printing press web are provided. The velocity is measured without contacting the web by measuring a speckle pattern which is reflected off the moving web by a laser. The reflected light is filtered and detected by a linear photodetector array which is differentially connected. The photodetector array output is fed into a differential amplifier to obtain a differenced output which has a frequency that is related to the velocity of the web. The difference output is filtered through a variable filter set at a predetermined bandpass center frequency and bandwidth, and its frequency is counted to obtain the approximate velocity of the web. Using the approximate velocity, a bandpass center frequency and bandwidth is selected which provides a substantially linear response of velocity at the counted frequency. The variable filter is reset to the selected bandpass center frequency and bandpass, and the frequency of its output is obtained.

Abstract: An activation signal is generated when an aircraft passes directly overhead and may be employed to record aircraft noise levels or to trigger a zenith camera for producing a photograph of the aircraft useful in determining aircraft position. When used in connection with a second instrument located at a fixed distance from the first and along the path of the aircraft, aircraft ground speed may be determined. Ambient light, normally passing through an optically defined airspace and thence incident upon light sensors, is partially blocked when an object such as an aircraft is present. A signal proportional to the change in ambient light incident upon the sensors and a function of the size and shape of the aircraft is used to sense the passage of a wing section. Upon detection of the wing section an activation signal is generated.

Abstract: The present invention is in the context of the measurement of velocity fields of fluid flows containing many small scattering sites, which exist either in the form of particles or optically activated, discrete fluid volumes. The invention is directed to a method and apparatus for resolving ambiguity with respect to the direction of displacement of particle images recorded by multiple exposures on film or videographic media. The invention enables the elimination of directional ambiguity by means of shifting the image field between exposures by an amount that is greater than any negative displacement occurring in the image field. In this way, all recorded displacements are positive, and negative displacements are obtained from the measurements by mathematically subtracting the artificial shift after the measurements.

Abstract: A unique electronic sensing screen apparatus for automatically measuring various parameters of moving projectiles. Projectiles pass between an artificial or natural light source and light sensors, resulting in signals from the sensors, which are processed into data showing projectile profiles or photo-like images, shock waves, velocity, angle of attack, and dispersion. The apparatus provides quick turn-around times between parameter measurements, such as those of many projectiles fired in rapid succession, and readily usable results.

Abstract: An aircraft velocimeter comprises means for projecting three pairs of independently generated ribbon-shaped laser beams to a measurement volume located at a predetermined distance from the aircraft with a predetermined separation being maintained between the two ribbon-shaped laser beams of each pair at the measurement volume. The times of flight of atmospheric aerosol particles between the two ribbon-shaped laser beams of corresponding pairs of laser beams are measured as the aerosol particles pass through the measurement volume. From the predetermined distance between the two ribbon-shaped laser beams of each pair and the measured time of flight of an aerosol particle across that predetermined distance, a component of velocity of the aerosol particle relative to the aircraft is calculated for each pair of ribbon-shaped laser beams.

Abstract: The velocity of a liquid jet, such as the headbox jet of a paper making machine, is measured by cross-correlation of a.c. signal components produced by a pair of light beams received by a pair of photodiodes. The light is supplied by a single source, an incandescent lamp, and is guided by a pair of bifurcated fiber optics mounted above the jet and spaced apart in the flow direction. The a.c. components are filtered to remove flow frequencies, amplified and then analyzed in a spectrum analyzer.

Abstract: An optical head, to which laser light is supplied, produces, in a measuring volume, at least two focusing points at which particles flowing through the measuring volume are illuminated and cause scattered radiation which is collected by the optical head. The laser beam is directed, via at least one first light guide, to the optical head. From the optical head, the radiation received from the measuring volume is supplied, via at least one second light guide, to a light receiving means. The optical head is small-sized and may be rotated about its optical axis by means of a rotating device.

Abstract: In strip casting, a melt is pressed between a travelling belt and a casting drum rotating along with the belt. A method and device for measuring the speed difference between the speed of the belt and the peripheral speed of the drum involves providing the belt on one side with a pattern of alternately darker and lighter stripes. Around the periphery of the casting drum there is arranged a number of measuring zones, each having the same width as that of the stripes. Each measuring zone includes a transducer built up of a number of photocells which, via optical conductors opening out to the measuring zones, can be activated by the stripes. When, during a casting operation, a measuring zone has arrived at a given measuring region, the number of activated photocells is read. The same procedure is repeated when the same transducer arrives at the end of the measuring region.

Abstract: The relative intensity of the transmit beam and the local oscillator beam in a ladar diplexer can be continuously adjusted during operation by using a rotatable retardation plate with a slightly inclined "C" axis to turn a polarized laser beam into a composite beam having two components polarized in mutually perpendicular directions. The relative intensity of the components is adjustable by varying the inclination of the "C" axis. The composite beam is applied to the same polarizer element normally used to separate the return signal from the transmit beam. The polarizer acts as the beam splitter which separates the local oscillator beam from the transmit beam. The described configuration also saves one beam splitter and allows improved packaging and alignment of the diplexer.

Abstract: A Doppler velocimeter having laser generating crossing light beams provides a crossing and focus area forming a measuring volume having regions of high and low light intensity. Solid or liquid particles moving through the measuring volume scatter light which is sensed and converted into a signal having a frequency. A signal processor measures the frequency by detecting and tracking an individual zero crossing of a particle through the measuring volume to provide real time information about the coherent component of the signal. This information is useable to determine the velocity of the particle moving through the measuring volume.

Abstract: The apparatus contains a dispersion means (DP) decomposing the incident laser beam into a number of colors (C1-C5) spacially separated from each other. The focusing points of said colors are subsequently traversed by particles contained in the flow. The light from the measuring volume (MV) is conducted via the dispersion means to a light receiving means (AV) in which the light is decomposed again into the individual colors. Due to a switching means (SE), the colors used for the measurment are selectible. Thus, the space of the focusing points used for the measurement may be varied.

Abstract: The present invention relates to a detector for a blade tracking system. The detector comprises a lens for focusing in a plane a bundle of radiation passing therethrough. Two or more radiation sensors are disposed within the plane, in such an arrangement that an object passing through the radiation bundle is sensed sequentially by the sensors.

Abstract: Apparatus for measuring velocity utilizes quadrature input signals provided by a transducer and divides the derivative of one of the signals by the magnitude of the other to obtain a measure of velocity. The apparatus may be digital or analog. It is particularly suitable for the measurement of velocity where the quadrature signals are provided by an optical grating and transducer arrangement.

Abstract: For the optical measurement of flow vectors in gas currents, two substantly parallel light beams are focused at separate focusing points. The particles traversing the one focusing point are illuminated and thus generate start pulses, while particles traversing the other focusing point produce, as they flash up, stop pulses. By means of such a process, it is possible to determine the component of the flow vector (v) extending in the normal plane to the vertical axis (OA). It is an object of the invention to detect by simple means also the flow vector component extending in parallel to the optical axis (OA). According to the invention, focusing points (FG1, FB2; FB1, FG2) of beams (S1, S2) with different focal distances are produced. In a first measurement (A), the straight line traversing the focusing points (FG1) and (FB2) is formed at an angle (.gamma..sub.A) to the normal plane of the optical axis.

Abstract: A method of measuring the interaction of a fluid with a wall bounding the fluid which method includes placing tracer particles in the fluid, illuminating the particles, and measuring the movement of the particles by means of scattered light, the improvement wherein the step of illuminating comprises illuminating a region of the fluid adjacent the wall at a distance of less than about 1 micron from the wall with a light beam directed towards the interface of the fluid and the wall so that the light beam is completely reflected; and the step of measuring comprises recording the scattered light images resulting from the motion of the tracer particles in the region and evaluating the motion of the fluid adjacent the wall. The invention also describes an apparatus for practicing the novel method.

Abstract: A portable modular music recording device which simply and unobtrusively attaches to a keyboard instrument for purposes of recording live musical performances; and an efficient music microcomputing system in which the captured musical data is digitized and further analyzed to determine note and note expression information when a key has been played. In the modular keyboard device, key and key expression data is captured by means of reflective couplers mounted in the keyboard device, and the information is transmitted to the processing unit. Microcomputer instructions refine the data to a format suitable for serial transmission via a computer-compatible link for ultimate scoring and recording.

Abstract: A photoelectric-piezoelectric velocity and impact sensor has a plurality of photoelectric light sources and associated photodetectors disposed on axes defining an array of light beams. A first electronic circuit is operatively coupled to the photodetectors for generating a signal representative of the moment in time when at least one light beam of the array is broken by a projectile passing through the array. A substantially planar transducer is disposed coplanar with and spaced apart from the array for generating a signal when the projectile strikes the transducer after passing through the array. A second electronic circuit responsive to the signal from the transducer is provided for generating a signal representative of the moment in time when the projectile strikes the transducer. A calculating circuit responsive to the signal from the first circuit and the signal from the second circuit is provided for calculating the velocity of the projectile as a function of the time difference between the signals.

Abstract: The present invention provides a method and apparatus to determine the position, velocity and orientation of an object with respect to an observation point. It consists of placing a sensor spaced from the object and placed at the observation point which will emit two non-parallel beams of light toward the object. Retroreflectors on the object will reflect the light in opposite direction to generate pulses of reflected light caused by the angular relative motion between the incident beam of light and the retroreflectors. A processor can be used to provide an indication of the position, velocity and orientation of the object based on the time interval between reflected pulses.

Abstract: Laser telemetry and Doppler measurement apparatus using pulse compression has a transmitter for providing a periodic pulsed transmission laser wave having a pair of pulses, one pulse being frequency modulated on one side of a main frequency F.sub.E, and the other pulse being frequency modulated on the other side of the main frequency F.sub.E. The transmitter also provides a reference laser wave having a frequency F.sub.L. A photomixer is adapted for superheterodyne reception of the reference laser wave and a return laser signal which has been reflected from a target. The return laser signal has a Doppler shift frequency F.sub.D. The photomixer provides a beat signal having a frequency F.sub.I plus F.sub.D, where F.sub.I is an intermediate frequency. A Doppler aquisition loop transposes the beat signal frequency and provides a transposed signal to compensate for the Doppler shift. The Doppler acquisition loop provides a coarse compensation signal having a frequency near the frequency F.sub.D.