Abstract: A laser proximity sensor for a projectile includes a laser diode having front and rear facets. The diode generates a main laser signal and directs a first portion thereof out of the front facet as a source beam. Focusing means focuses the source beam on a target, and focuses the return beam reflected from the target into the laser diode through the front facet. The laser diode receives the return light beam, provides it with a positive gain, mixes it with the main laser signal, and guides it out the rear facet as a mixed beam. A detection focusing device focuses the mixed beam onto a PIN detector. The PIN detector coherently detects the mixed beam and provides an output signal having a perturbation where the target enters the focal field of the focusing optics. A processor detects the output signal from the PIN detector and may activate a fuse on the projectile.

Abstract: A jet velocity measuring apparatus is disclosed for measuring the velocity of a fluid stream. The apparatus (10) measures the time delay between primary electronic signals generated by a first photosensitive device (32) as a result of a first beam of light from a light source (34) being reflected by a portion of the surface (S) of the stream (24) and secondary electronic signals generated by a second photosensitive device (36) as a result of a second beam of light from a light source (38) being reflected downstream by substantially the same portion of the surface of the stream (24). The apparatus includes a housing (22) disposed parallel to the plane (P2) of the surface of the stream. A first and a second fiberoptic bundle (42, 44) transmit light from the light source (34, 38) to the surface of the stream (24) and back respectively to the photosensitive devices (32, 36). Debris-deflecting slots (88, 90) are disposed adjacent to the housing (22) for deflecting debris therefrom.

Abstract: A method is indicated for the contactless measurement of the relative movement of an object (14) relative to a scannable pattern (12), a scanning beam (31) being generated which scans a portion of pattern which moves with the object along a scanning path on the pattern in order to produce a scanning signal.

Abstract: A hybrid optical/digital method for measuring the displacements of compact images, in particular, particle images recorded on photographic or other recording media in multiple exposure photography. The method compresses the two-dimensional image field of the particles into two one-dimensional line images that are perpendicular to each other. The mean particle displacement between multiple exposures is determined by digitizing the one dimensional images, computing their autocorrelations, and locating the peaks of those autocorrelations. This method is particularly adapted to measure the velocity fields in fluids containing many small particles. Alternatively, when the first and second images of a single particle are the only images in the image field, the displacement is found by locating the peak of each image.

Abstract: For passive range metering of moving vehicles a receiver is used having two detectors spaced apart and directed to the path of the vehicle which moves with constant speed and the length of which is known. The receiver measures the pass-through time of the image of the vehicle through the first detector and furthermore measures the traveling time of the image of the vehicle from one detector to the other. The distance E can be calculated by equation ##EQU1## wherein f is the focal distance of the receiver optics, Q.sub.t is the quotient of the measured time values, l is the length of the vehicle.

Abstract: A method for measuring the velocity of a scatterer in a moving fluid by examining the spatial structure of the optical field on the detector of a Laser Doppler Velocimeter (LDV). The optical field after scattering from the laser beam is a traveling wave of a shape dependent on the detector optics alone. A pair of differential linear arrays are used to find the direction of velocity of the traveling wave and hence that of the scatterer. Furthermore, this method eliminates the Doppler pedestal which requires high pass filter in most of the conventional methods.

Abstract: Method and apparatus for optical measurement of fluid flow in which particles are injected into the fluid flow to permit accurate velocity measurements to be made thereof between two laser beams through measuring windows and to obtain a velocity profile. One beam is fixed and provides indication of start event, and the other beam is moved in discrete angular steps around the first beam in oscillatory fashion to provide indication of stop events. The sum of the particles passing the start beam and the sum of the particles subsequently passing the stop beam are correlated by electronic evaluation circuitry.

Abstract: A radiation detection method utilizing essentially two serial arrangements of receiving elements which are rigidly connected to a reconnaissance plane (1) and of different lengths, which yield in longitudinal direction of sight the censor angle .epsilon. and on the ground the pictorial strips (6, 6'). The pictorial strips are arranged transverse to the axis (25) of the plane and parallel to each other. The processing of the signals is such that, by scanning the two serial arrangements with a time delay, a different signal signature results only if the scanned object (2) moves during over flight, independently of whether the reconnaissance plane (1) during the measuring operation is subject to a pitch angle .alpha. and/or a side slip angle .beta. and/or a roll angle speed. Moreover, in this way, it is also possible to independently obtain the target speed and direction.

Abstract: Pulse-tone laser radar utilizing an acousto-optic angular multiplexer and frequency shifter. The laser radar includes both a pulsed laser and a CW laser. A portion of the CW laser beam is utilized as a reference or local oscillator. An acousto-optic angular multiplexer passes the output of the pulsed laser when the acousto-optic multiplexer is in its off state and passes and frequency shifts the output of the CW laser when the acousto-optic multiplexer is in its on state. The acousto-optic angular multiplexer is operated to pass a pulse followed by a CW tail to generate the pulse-tone waveform. The return signal from a target is beat together with the local oscillator signal derived from the CW laser. The resulting beat signal includes both range and velocity information.

Abstract: The present invention is concerned with directly measuring belt speed by placing two high resolution single fiber optical reflectometers a known distance apart on a line parallel to the belt motion. The signal from the first reflectometer is delayed and the cross correlation function of the two signals is calculated in real time. The cross correlation function can be maximized by varying the delay. When the maximum is observed, the belt velocity may be found by dividing the reflectometer separation by the delay.

Abstract: A collision avoidance system for preventing collision between vehicles capable of moving along the same general path, which system includes a vehicle having a device for emitting optical pulses and another vehicle having a detector which uses an optical scanner defining a substantially triangular scan field. The detector responds to the emitted optical pulses and determines the range between the vehicles and the closing speed between them. An alarm system responds to the closing speed determination to permit evasive action to be taken when the closing speed exceeds a selected value.

Abstract: A method of measuring the moving velocity of a linear object which is moving while vibrating, the method comprising the steps of illuminating the linear object with a flat laser beam having a width larger than the amplitude of vibration, the linear object moving in the direction of its length and vibrating perpendicular to the longitudinal direction; receiving the scattered light from the linear object by a photoelectric conversion device through a finite-sized elliptic or slit aperture disposed with the direction of its minor axis matching the direction of movement of the linear object; and cutting off the d.c. component of a speckle signal from the photoelectric conversion device, counting the number of zero-crossings per second of the resulting signal and converting the count value to a signal representing the longitudinal moving velocity of the linear object.

Abstract: An automatic digital light source adjustment procedure is disclosed wherein a computer calculates a correction factor for each of a plurality of light sources and adjusts the light sources such that each of the light sources meets an optimum performance criteria. In one embodiment, a multicolor cathode ray tube is converged automatically utilizing the present invention by sensing the profiles of the amplitudes of the individual color light intensities versus the same light source position relative to the sensor mechanism for each of the three primary colors, calculating the correction factor and inputting the correction factor to a digital memory, and then providing for the correction factor to be applied to the analog output of the beam control thereafter. Alternative embodiments enhance focus, purity, light line width, color composition, and other performance factors.

Abstract: An apparatus and method for determining aircraft position and velocity is disclosed. The system includes two CCD sensors which take overlapping front and back radiant energy images of front and back overlapping areas of the earth's surface. A signal processing unit digitizers and deblurs the data that comprise each image. The overlapping first and second front images are then processed to determine the longitudinal and lateral relative image position shifts that produce the maximum degree of correlation between them. The signal processing unit then compares the first and second back overlapping images to find the longitudinal and lateral relative image position shifts necessary to maximize the degree of correlation between those two images. Various correlation techniques, including classical correlation, differencing correlation, zero-mean correction, normalization, windowing, and parallel processing are disclosed for determining the relative image position shift signals between the two overlapping images.

Abstract: Improved detector and processing circuitry for use with a vorticity measurement optical probe system is disclosed. The invention makes use of a dual axis position indicating photodetector so that two components of vorticity may be simultaneously measured. Reflective spherical particles are disposed in a fluid whose vorticity is to be measured, and a light beam is reflected off of the particles and onto the photodetector. Analog and digital processing circuitry is connected to the outputs of the photodetector, and generate data that is indicative of the position of the reflected light beam on the photodetector as a function of time. Computer interface circuitry is also provided which enables the beam position data to be read into a digital computer so that the two vorticity components may be calculated therefrom. Embodiments which utilize plural axis photodetectors are also disclosed.

Abstract: Method and apparatus are disclosed for determining one or more physical characteristics of individual bubbles in a gas-liquid system and a gas-liquid-solid system at high temperatures and pressures. An in situ probe device is inserted into the system over which individual bubbles flow. The probe device has a plurality of independent probes. Each has a rounded fibre optic end portion projecting into the system. A source of incident light is directed onto each of the probes. The rounded end portion of each probe is formed with a radius of curvature sufficiently large whereby the angle of incidence of the source light at the rounded portion is greater than the angle of total reflection for the fibre optic when in contact with the gas. The angle of incidence is less than the angle of total reflection for the fibre optic when in contact with the liquid. The plurality of probes are spatially arranged to detect one or more of the bubble physical characteristics as a bubble flows over the probe device.

Abstract: A method of measuring the velocity of a fluid by noninstrusive means comprises passing a pump laser beam pulse through the fluid wherein the fluid contains a constituent absorbing the wavelength of the laser so that a temperature gradient, and therefore an index of refraction gradient, occurs in the laser beam path; and a probe laser beam is passed transverse to the pump laser beam and is deflected by the heated portion of the fluid; measuring the beam deflection and calculating from that the fluid velocity. After the pump pulse the amount of deflection reaches a peak value and then decreases at a rate independent of the concentration of the absorbing constituent. Where the pump laser beam has a Gaussian spatial profile, the deflection signal decreases according to: exp-2(v+/a).sup.2, where v is the velocity; t is time; and a is a constant representing the pump laser beam radius.

Abstract: A moving body measuring instrument is disclosed which projects, from predetermined locations thereof, a plurality of beams of light at predetermined angles into a same plane, receives, at predetermined locations thereof, the beams reflected from a moving body as it moves to intersect with the beams, calculates parameters of the motion of the moving body in accordance with predetermined operation from timing data of the beams received, and indicates the results of the calculations on an indicator. The moving body has a light reflective member provided thereon which reflects a beam for measurement toward a direction incident thereto irrespective of its incident angle, and substantially same locations are provided at which beams are projected and received.

Abstract: A method of measuring the velocity of a fluid by nonintrusive means comprises passing a pulsed pump laser beam through the fluid wherein the fluid contains a constituent absorbing the wavelength of the laser so that a temperature gradient, and therefore an index of refraction gradient, occurs in the laser beam path; and a probe laser beam is passed transversely to the pump laser beam and is deflected by the heated portion of the fluid by an amount which is proportional to the concentration of the absorbing constituent and inversely proportional to the velocity of the fluid; measuring the beam deflection and calculating from that the fluid velocity, if the concentration of the absorbing constituent is known, or calculating the relative velocity if the concentration of the absorbing constituent is constant.

Abstract: A method and apparatus for selectively translating the path of at least one pair of light beams in a Laser Doppler anemometry device whereby the light paths are translated in a direction parallel to the original beam paths so as to enable attainment of spacial coincidence of the two intersection volumes and permit accurate measurements of Reynolds shear stress.

Abstract: A laser detection system is disclosed. Optical means projects light scattered from a moving localized portion of the beam onto a photosensitive strip. Voltage applied across the strip causes the light generated electrons therein to move through the strip at the same rate as the scattered light from the moving localized portion of the beam projected onto the strip moves across the strip so that all the electrons generated in the strip are detected as an accumulated charge at one end thereof.

Abstract: An optical radar system for vehicles has a stationary receiver and a transmitter which scans the road surface ahead of the vehicle, the scan area being shifted in accordance with the direction of steering of the vehicle. The scan area is covered by periodically sweeping a narrow-beam pulse laser through the designated scan area and monitoring the return lag of pulses reflected by objects in the scan area. The scan area is centered over the longitudinal axis of the vehicle while the latter is moving straight ahead. The axis of the scan area is shifted in proportion to the orientation of the steering wheel of the vehicle.

Abstract: A laser Doppler velocimeter (LDV) system (10) has a laser (12), a waist position adjusting lens (13), and a beam splitter (15), which direct laser beams (14) parallel to optical axis (16) of negative lens (18). Negative lens (18) is fixed relative to afocal lens pair (24,26). A pair of planar mirrors (20, 22) intersect at right angles and respectively intersect optical axis (16) and optical axis (28) of the afocal lens pair. Mirrors (20, 22) are movable along optical axis (28) toward and away from afocal lens pair (24, 26) to focus laser beams (14) in focus area (30) while maintaining a constant beam waist, crossing angle and intersection with other laser beams to produce a constant sensitive volume as the focus is changed.

Abstract: Method and apparatus for automatically controlling aerial photographic cameras. An exact and reliable control device of low electronic and optical cost, which unburdens the operator, is realized by means of two photoreceiver lines positioned parallel to each other and perpendicular to the flight direction. At least the first line is connected to a data memory, which as well as the second line is connected to a correlator. The correlator is connected, via units for calculating the vg/hg ratio and/or the drift, to setting mechanisms of the aerial camera. A third photoreceiver line can also be provided, coupled subsequently to a data memory. The invention is utilizable in photogrammetry.

Abstract: A method and apparatus for measuring the velocity of moving particles such as red blood cells in a tissue sample is disclosed, characterized by digital processing techniques and autocorrelation. The moving particles are illuminated to produce a spread spectrum optical signal resulting from the Doppler shift occurring when photons are scattered by the moving particles. A spread spectrum electrical signal corresponding with the optical signal and containing spectral and noise components is generated from the optical signal. The electrical signal is filtered to produce the bandpass and DC signals which are subsequently converted to digital form. A first autocorrelation function is calculated from the bandpass signal and a noise autocorrelation function is determined in accordance with the DC signal level. The first and noise autocorrelation functions are compared to produce an autocorrelation function free of a noise component.

Abstract: Apparatus for measuring the velocity of a moving image or object including a first array of sensors extending in a first direction transverse to image motion for sensing a primary set of image elements; a second array of sensors extending generally in the first direction and spaced a known distance from the first array for sensing successive sets of image elements; a device for correlating the primary set of image elements with each of the successive sets of image elements and for producing a correlation level indicating the level of correlation of the primary set with each of the successive sets; means for selecting one of the correlation levels which indicates an optimal level of correlation; and means for determining the time interval between the sensing of the first array of the primary set and the sensing by the second array of the successive set corresponding to the selected correlation level; in addition, the means for correlating may include means for comparing with the primary set each successive set

Abstract: A method and system for measuring relative speed of a ship through a body of water with improved accuracy and simplicity. It employs a free floating buoy and a pair of tracking scopes. The buoy is launched and tracked by the scopes with electronic circuit arrangements so that the time of relative movement of the buoy between transverse positions opposite the scopes is accurately measured.

Abstract: In a laser-doppler-anemometer two frequency-displaced partial beams are transmitted from a transmitted device including a laser to a measuring probe positioned at a remote measuring volume by means of a polarization-direction-preserving optical "single-mode" fiber with two orthogonal principal axes, the transmitter including a member for turning the polarization direction of one partial beam by 90.degree., and the measuring probe including another polarization-direction-turning member for re-establishing the original coincidence between the polarization directions of the two partial beams. The transmitting device may thus be positioned at a distance from the measuring volume while the measuring probe may be designed with small physical.

Abstract: The measurement of the velocity of a flow in a water flow model, characterized by conducting into a model water tank water containing a large volume of fine, uniform air bubbles to form a simulated field of flow; projecting a slit of light on said field of flow; photographing the slit of light beams with a television camera and displaying said photographed beams of light on the screen of a monitor television set; measuring changes of said displayed, irregularly reflected beams of light at two close points with two photosensors on said screen; determining a time interval in the changes of irregularly reflected beams of light at said two close points and finding the velocity of said flow with said time interval taken as defining the duration required for the pictured aggregate of air bubbles to move from one to the other of said two photosensors.

Abstract: The multiple measuring control volume laser Doppler anemometer includes a laser for providing an optical beam. The beam is transformed by an optical arrangement to produce a number V of measuring control volumes wherein each control volume has two focussed optical beams intersecting at a unique predetermined angle .phi.. A detector collects the scattered light from the measuring control volumes in order to determine the velocity at each of the control volumes.

Abstract: The invention relates to a method and apparatus for measuring the velocity of a moving object. Measuring beams composed of sequences of optical pulses are directed towards the object which is to be measured and follow such object. Based upon transit time measurements of reflected pulses there are formed distance values and distance difference values. While taking into account the time interval of the pulse sequence there are computed velocity measuring values and velocity values computed from homogeneous groups of values are displayed as reliable velocity values.

Abstract: An optical radar is disclosed in which fine vernier range and angular displacement accuracy is achieved by projecting a burst of coherent pulses so as to strobe a target passing through the field of view of the projection apparatus. The use of the pulse burst permits the most recent information to be utilized in obtaining the target track. Prior to projection, the pulses in the burst are sampled. The resulting signal is delayed by an amount corresponding to course range and is directed down one of a pair of oppositely directed delay lines. The signals returned from the target are detected by a sectorized receiver, with an electrical output signal from a detector in one of the sectors being applied to the other delay line in the corresponding pair, such that the signal corresponding to the returned pulse propagates in a direction opposite to that of the sampled signal corresponding to the transmitted pulse.

Abstract: Apparatus for measuring the velocity of, for example, an aircraft includes two optical units spaced a predetermined distance apart along an axis, there being a plurality of pairs of associated radiation detectors, with each pair of detectors having one detector in each unit, the planes of lines of sight of each pair of detectors extending parallel to each other, with these planes of different pairs of detectors being inclined relative to each other, in a measurement period, comparing means of the apparatus determining the delay between the forward and aft detectors of at least one pair of detectors receiving radiation from the same part of the same portion of the plane of a radiation source, such as the terrain, and from this determination the velocity being represented, the comparing means possibly comprising a known form of correlator, possibly provided by a digital computer, the computer possibly also providing axis transformation means within the apparatus.

Abstract: A fall velocity indicator/viewer having a sampling compartment, a camera system, and an elongated tunnel for interconnecting the camera system to the sampling compartment. The camera system includes a video camera for continuously monitoring snowflakes as they naturally fall through a viewing area in the sampling compartment. The snowflakes are illuminated by a pair of strobe lights directly and in combination with reflected light from a pair of mirrors. In addition, a mirror in the tunnel provides a reflected view from the top of the snowflakes. The video camera is capable of thereby monitoring multiple views of snowflakes in a single video frame and provide sufficient data to analyze the physical characteristics of the snowflakes as well as aid in making velocity determinations and other observations of naturally falling snowflakes.

Abstract: A system for determining the ground velocity of an aircraft is disclosed. The system includes a CCD linear optical image sensor carried by the aircraft for forming a first and second substantially instantaneous light intensity contour of the optical image of the surface of the earth lying below the aircraft. The two contours are delayed in time with respect to each other. A computer, included in the system, compares the two contours to determine the relative position shift between the two contours by utilizing cross-correlation techniques. The computer then corrects the contour position shift for the aircraft altitude and divides the corrected position shift by the time delay between the two contours to obtain the aircraft ground velocity. A signal indicative of the aircraft ground velocity is output by the system.

Abstract: A method and apparatus for extracting information from an object within a large interrogation zone by utilizing a retroreflective backing to define the location of the object and/or information on the object, and an apparatus designed to eliminate from consideration all specularly and diffusely reflected light otherwise present within the zone and thereby isolate the retroreflective backing within the zone. The apparatus then extracts the information which was defined by the retroreflective backing.

Abstract: An obstacle detection system for vehicles comprises a laser radar mounted on the front end of a vehicle and modulated by drive pulses of high rate. The laser pulses are deflected in two orthogonal directions by paired deflection signals fed from a deflection driver to paired acousto-optic light deflectors to digitally scan a space ahead of the running vehicle. The deflector driver supplies paired deflection information to arithmetic logic means. One deflection signal fed to one deflector has a rate much higher than the other and is synchronized therewith. When receiving a return pulse by a photo-detector, a video pulse of substantially constant level is reproduced by a sensitivity time control function. The distance between a target and the vehicle can be registered in a binary counter. Relevant distance information is supplied to the arithmetic logic means. The latter provides a decision of whether a possibility of collision exists and produces an alarm when the distance approaches a stopping distance.

Abstract: Reflections, having positive and negative Doppler frequency shifts, from a laser beam directed at a moving surface are passed through spatial filters, combined by a beam splitter, and focussed on an observation plane of a photodetector to provide a fringe pattern having an amplitude variation frequency responsive to the velocity of the moving surface. The laser beam may be a single beam directed substantially perpendicularly to the moving surface, or the laser beam may be divided into two beams angled toward the surface, one beam impinging with the direction of motion of the surface and the other beam impinging against the direction of motion. When two impinging beams, split from a common beam, are utilized, different polarizations and beam impingement points on the surface may be used to provide beam isolation between the beam signals. Homodyne detection with single frequency lasers is used.

Abstract: A laser range meter utilizing a mode locked laser for transmitting ultrashort pulses toward a target and a receiver for cross correlating the pulses returned from a target with corresponding reference pulses derived from the transmitted pulses is disclosed. Cross correlation is accomplished with a nonlinear element which responds to the return and reference pulses by producing secondary radiation of longer duration and of an intensity indicative of the time correlation of the pulses. The secondary radiation is sensed with a photodetector whose output signal is supplied to an output device.

Abstract: A video flowmeter is described that is capable of specifying flow nature and pattern and, at the same time, the quantitative value of the rate of volumetric flow. An image of a determinable volumetric region within a fluid (10) containing entrained particles (12) is formed and positioned by a rod optic lens assembly (31) on the raster area of a low-light level television camera (20). The particles (12) are illuminated by light transmitted through a bundle of glass fibers (32) surrounding the rod optic lens assembly (31). Only particle images having speeds on the raster area below the raster line scanning speed may be used to form a video picture which is displayed on a video screen (40). The flowmeter is calibrated so that the locus of positions of origin of the video picture gives a determination of the volumetric flow rate of the fluid (10).

Abstract: A particle size measuring apparatus and method has a laser unit and optics that provide a central focused light area surrounded by an annular focused light area. Particles moving with fluid through the center of central focus light area cause the light to scatter. The scattered light is sensed and converted to readable signals indicative of particle size.

Abstract: An optical system for direct measurement of vorticity in a flowing fluid is disclosed. Spherical particles suspended in the flow rotate with an angular velocity that is accurately equal to half the local vorticity; thus, measurements of the rotation rates of such particles indicate the vorticity. The particles are transparent, and preferably are less than 50 .mu.m diameter, and each contains embedded planar crystal mirrors. The particles are suspended in a refractive index matched liquid. Measurement of the particle rotation rate and thus the vorticity of the fluid is preferably accomplished by measuring the rotation rates of reflections of one or more light beams from the planar mirrors. The measurements may be carried out using any system of position sensitive optical detectors such as photo sensitive devices screened by suitable slits or photo diode arrays.

Abstract: A light source illuminates particles migrating in an electrophoresis chamber under the influence of a reversing polarity electric field applied between a pair of spaced electrodes which are in the form of thin conductive layers deposited on opposed end portions of the chamber. The light reflected from the particles migrating along the stationary layer of the chamber is imaged onto a circumferentially arranged grating on a transparent rotating disk and modulated thereby.

Abstract: Apparatus for monitoring the flow of a stack of cigarettes in a conveyor system using a television camera tube or light-sensitive detectors positioned adjacent the ends of the cigarettes, preferably in an array or row covering the whole height of the stack, to monitor the formation of the stack and to produce pulse signals representing the articles present. The sensors are scanned by control circuitry which produces control signals in response to the number or speed of articles detected.

Abstract: An optical velocity measuring apparatus applicable to measurement of the velocity of a vehicle relative to the road. A pair of light sensors mounted on the bottom of the vehicle body spaced from each other in a direction of the movement of the vehicle respectively receive rays of light reflected from different spots on the road through an optical system and produce electric signals indicative of the surface conditions of the spots. A time lag from the detection of a particular spot by the forward light sensor until the backward light sensor detects the same spot is measured to determine the velocity of the vehicle. The optical system is comprised of first and second lenses each having a peripheral portion cut away by a plane parallel to the optical axis. The first and second lenses are aligned so that the cut away faces are in contact with each other and that the optical axes are in parallel to and spaced a predetermined distance from each other.

Abstract: For continuous measurement of the linear speed of relative travel of an object 11 in front of a measuring device 10 two fixed zones 21,22 in the path of the object are illuminated by means of two parallel laser beams emitted by a single source 15, images of the two zones illuminated are formed upon one and the same transducer 17 the output signal from which is processed electronically by autocorrelation in order to determine the time of travel of a point on the object in going from one illuminated zone to the other.

Abstract: Disclosed herein is a method and apparatus for determining the velocity and direction of motion of moving object by directing two coherent light beams onto the object and thereby causing moving speckles including information on the velocity to be formed in a diffraction plane, deriving time-space cross-correlations from the variations of time-space intensities of the speckles, analyzing the motion of the object in the two directional components based on the time-space cross-correlations and determining the velocity and direction of motion at the same time.

Abstract: The invention contemplates use of a cylindrical lens oriented transverse to an aircraft axis, in conjunction with two light-sensitive detectors in the image plane of the lens, to develop two time-displaced electrical output signals which represent aircraft-motion scanning of terrain by the respective detectors; basically simple circuitry develops the velocity-altitude ratio by measuring the instantaneous displacement time between the two signals. The same cylindrical lens and detecting circuitry may be provided in multiple and in particular relative orientations, to additionally develop drift-angle of the aircraft axis with respect to its instantaneous ground-velocity vector.

Abstract: The invention relates to an arrangement for automatically focusing the image of an object, obtained by an objective lens system, onto an image plane by adjustment of the distance of the objective lens system or a portion thereof from such image plane. Two optical devices which are mutually offset transversely to the optical axis, are provided for obtaining auxiliary images of the object, which are photoelectrically analyzed with respect to one another. The minimum difference signal therebetween indicates the congruency of the two auxiliary images and supplies an adjustment criterion for a device operative to correspondingly adjust the objective distance. The invention utilizes two CTD image sensors to analyze the auxiliary images with the read-out signals being supplied to a differential amplifier and subsequently rectified and integrated.

Abstract: The invention relates to an arrangement for measuring the range or speed of an object, in which two optical devices are offset from one another transversely to the direction of the object to produce auxiliary images of such an object, which are photoelectrically analyzed relative to one another. The minimum difference signal indicates the congruency of the two auxiliary images and supplies a criterion for the range of the object. In accordance with the invention, the auxiliary images are analyzed by CTD image sensors, whose read-out signals are supplied to a differential amplifier and are then rectified and integrated. The read-out signals from one sensor are changed, as to their phase state, with respect to the read-out signals from the other sensor, by means of a pivotal movement of the relevant optical device, by means of a delay element which can be adjusted in a stepped manner. The range criterion is obtained from the phase state assigned to the minimum difference signal.