Abstract: An IR sensing system wherein the focal area is located outside the casing at holds a detector array and a bundle of optical fibres leads from the focal area to the detector array in the array such that the inner, emitting end of each fibre of the bundle is in proximate relationship with only one single detector.

Abstract: Apparatus and methods for modifying existing forward looking infrared systems and for forming new forward looking infrared systems. Generally, the system comprises a Galilean afocal system in combination with a reimaging afocal system. A reimaging afocal lens system is formed with at least first and second lenses and a plane for forming an image therebetween. A thermal reference source is positioned in the imaging plane of the reimaging system. The method for modifying an existing forward looking infrared imaging system includes positioning the reimaging system along the optical path of the system between the Galilean lens combination and the scanning device. According to a method for forming a forward looking infrared system an imaging lens system is arranged along an optical path in combination with a detector array to focus collimated radiation upon the detector array. The detector array subtends the field of view along a first direction.

Abstract: A method for detecting a thinned out portion on the inner surface or the outer surface of a pipe, comprising heating or cooling a pipe to be tested from the outer surface or the inner surface thereof so that a difference in temperature is produced between two portions of the outer surface or the inner surface of the pipe corresponding to a thinned out portion and a normal portion of the inner surface or the outer surface of the pipe; shooting the outer surface or the inner surface of the pipe by means of a thermal imaging system to obtain a thermal image of the difference in temperature; and then calculating a differential value of a temperature distribution of the thermal image of the difference in temperature on a line passing the highest temperature point or the lowest temperature point in the thermal image of the difference in temperature.

Abstract: A 360 degree surveillance system for detecting an infrared IR signal coming rom a scene. The IR signal is reflected by the scanning mirror to an imaging lens. The scanning mirror rotates 360 degrees around a vertical axis. The imaging lens images the IR signal through a derotator onto a linear array of IR detectors. The derotator serves to keep the image of the IR scene in a proper orientation. The detectors sense the IR signal and produce a current proportional to its strength. Each detector is the beginning of a channel of information. Each channel has operational amplifiers to process the signal, control gain, restore dc, etc. The output of the amplifiers are fed to a linear array of LED's. The light output of the LED's passes through a rotator and is imaged by a projector lens, after reflection off a rotating mirror, onto a cylindrical screen. The purpose of the rotator is to keep the image of the LED's in the proper orientation on the screen.

Abstract: An electro-optical target acquisition system having a scanning mirror which otates through a 360.degree. azimuthal plane. The infrared (IR) signal of a target is reflected off a mirror and imaged by a lens through an optical derotator onto a linear array of IR detectors. The detectors produce a current proportional to the strength of the IR signal. The current of each detector channel is amplified and fed to a corresponding light emitting diode, LED, that is part of a linear array of diodes. This light is imaged by a coupling lens through an optical rotator onto the photosurface of an image intensifier tube. The light image of the LED's creates a corresponding electron image. The electron image is swept across the tube and impinges onto the tube's phosphor output plate and creates a light output. The light output is an intensified image of the LED's.

Abstract: A 360 degree infrared surveillance system comprising a scanning head rota on a turntable having optics and IR detectors in a vertical linear array, amplifiers for each detector and light emitting diodes for each respective detector/amplifier channel. The light from the LED's is imaged onto photodetectors whose output is amplified and fed to a corresponding LED. An optical rotator causes the image of their light to rotate. A lens images this light onto photodetectors located on the projector turntable, rotating synchronously with the scanner head. The photodetector current is amplified and fed to a linear array of LED's and imaged onto a cylindrical screen for display.

Abstract: An internal calibration source for an infrared radiation detector has a low emissivity surface with a high emissivity reticle thereon. An image of the detector is focused on the surface so that it is retroreflected back to the detector. The image is scanned between the high and low emissivity regions during calibration.

Abstract: A method and apparatus is provided to effect the contactless testing of the surface and inner structure of a solid workpiece, wherein a single pulse of an electromagnetic exciting beam, preferably of a focused beam, is projected against the workpiece and the effect of the locally and temporarily induced workpiece temperature, measured as generated infra-red radiation, is processed, providing information concerning the surface and inner structure of the workpiece. The single pulsee of the laser beam is broken up into a multiplicity of component beams whose images, simultaneously projected upon the workpiece, are combined in a field or line by means of which the workpiece is analyzed.

Abstract: A video scanning and signal processing arrangement usable with devices such as a forward looking infrared system. The signal processing disclosed employs an analog-to-digital converter of limited dynamic range and incorporates plural closed loop signal modifying for optimizing the use of this limited dynamic range.

Abstract: The present invention is concerned with displaying moving objects (targets) wherein two time-shifted object signatures are imaged on a detector. Target scanning is with a prismatic rotating wheel, the periphery of which has a plurality of adjacent, recessed, and oppositely reflecting triplet mirror surfaces which alternately reflect the two signatures onto the detector. The position coordinates of the objects are defined by taking the difference of the detector output signals of the two object signatures. The display is characterized in that the first signature scan is delayed by an intermediate storage so that it shall be simultaneously available with the second signature scan. After taking the difference of the signals of these signature scans, the uncanceled individual signals remaining in the storage are defined as the coordinates of the moving objects and appear as electronic outputs.

Abstract: An infra-red imaging system is operable selectively in wide and narrow field of view modes. Radiation from the object is imaged onto an infra-red CCD staring focal plane array (SFPA) which provides an output representing the image. In the narrow field of view mode, operative on detection of a particular target by target detection electronics, the image is not scanned but is made to follow any movement of the target, and the SFPA stares at the target to build up an image. In the wide field of view mode, the same SFPA is used to provide the image, but the image is scanned along a swath. Smearing of the image is minimized by driving the IRCCD array such that the image-bearing charge is passed down the array from element to element at a speed equal to the scanning speed, so that the output signal from the end element represents the intensity of radiation from a given portion of the object time-integrated by all the elements of the array in succession.

Abstract: An electrooptic support measure comprised of black hole radiometer within a orward looking infrared (FLIR) scanning imaging video processing system to provide friendly military personnel with the capability of surveying terrain to determine if enemy thermal imaging devices (TIDs), which have cryogenic temperature detectors therein, are being used in surveillance against the friendly military personnel. The lens and scanners of the FLIR scanning imaging video processing system have wide field of view (FOV) for search operation, and each of the plurality of the IR detectors that form an IR detector array operate as a plurality of radiometers having narrow (FOVs) when the black hole radiometer capability circuit of this disclosure is being used.

Abstract: A thermal wave three-dimensional imaging and tomography apparatus and a thermal wave detector therefor are provided. The apparatus includes a light source for generating a laser beam which is modulated and then focussed onto one side of a solid test material. A thin pyroelectric polymer electret (.beta.-PVDF) film having an electroded upper surface and an electrodeless lower surface supports the other side of the test material on its electroded surface. A single thin metal elongate pin or an array of thin metal elongate pins are disposed beneath the electrodeless lower surface. The pin or pins generate(s) signals upon detection of thermal waves passing through the solid test material resulting from the laser excitation due to the photopyroelectric (P.sup.2 E) effect. Since the pins are small, the signals generated by the pins represent local thermal wave progagation through the test material.

Abstract: The disclosure relates to a system for on-line normalization of the outputs of all of the detector elements of an infrared detector wherein, during the retrace period of the scanning mirror, infrared energy from a controlled thermoelectric source is reflected first from a high reflectivity sector of a rotating mirror and then from a relatively low reflectivity sector of the rotating mirror onto the detector. The detector output for the high and low reflectivity input signals is analyzed on a channel by channel basis by software controlled hardware and the gain of each channel is then adjusted in response thereto by the software controlled hardware individually. In this manner, each channel is caused to provide the same output for an identical input thereto.

Abstract: A thermal imager having an array of sprite detectors is provided with a novel means for reducing or eliminating lininess in the reproduced image. This means comprises a low pass optical filter which cuts out wavelengths above 11.5 microns and adjustable gain buffer amplifiers in the respective channels. It is found that with the use of the optical filter the gains of the buffer amplifiers may be preset, when setting up the apparatus, to eliminate lininess and it is not necessary to include complex and noisy circuitry for continuously monitoring the signals output by the detectors and then applying appropriate corrections to the individual channels during operation of the apparatus, as in the prior art.

Abstract: An method and apparatus for amplifying signals from an elemental detector in a detector array (10) is disclosed. The apparatus comprises a preamplifier (26) for amplifying the output of the elemental detector. The preamplifier comprises first differential amplifier (170) and a circuit (174) for lowering the gain of the first differential amplifier. The apparatus further comprises a postamplifier (28) for amplifying the output of the preamplifier (26). The postamplifier (28) comprises a second differential amplifier (370) and a circuit (374) for lowering the gain of the second differential amplifier.

Abstract: A detector array for use in an infrared linescanner system. The system scans an area of ground below an aircraft. The detector array comprises a linear array arranged in a symmetrical pattern about a centerline and has an angular overall length sufficient to provide contiguous coverage of the scanning area for a maximum specified velocity-to-height ratio.

Abstract: A thermal imager including a cryogenically cooled detector element array and a scanning element has an optical system with a field of view limited by a field stop (2). A retroreflective region (6) is provided on part of the field stop to act as a temperature reference by allowing the detector array to "look at" itself. A second, different temperature reference (5) is provided on another part of the field stop and the two references are used to equalize and adjust the output characteristics of the elements in the detector array.

Abstract: Between the spaced biasing electrodes of a thermal radiation imaging device A D.C. bias source is connected to cause the flow of a bias current in the device body which is preferably of n-type cadmium mercury telluride. The bias current supports an ambipolar drift of radiation-generated minority carriers (holes) in the opposite direction. The device is operated in a system in which the radiation pattern is scanned across the device body in the same direction and at the same rate as the ambipolar velocity. Instead of having a single read-out electrode, a more sophisticated system with better performance is obtained by distributing between the spaced biasing electrodes a plurality of read-out electrodes each of which forms a Schottky barrier or p-n junction with the body material.

Abstract: An image of a target (11) is produced by illumination of the target (11) with overlapping fields (18, 20) of wave energy, such as coherent light, producing an interference pattern (22) moving across the target. At least one pair (12) of sources (14, 16) wave energy provide the moving interference pattern (22). The scattered illumination reflected from the target is detected by a non-imaging receiver (24); a two dimensional spatial frequency map is recorded (30, 62), based upon the amplitude, frequency and phase of the illumination received; and a two dimensional image of the target is formed (32, 72) by applying a Fourier transform to the two dimensional frequency map.

Abstract: A detector, of photosensitive semiconductor material with input and output bias contacts. To improve both frequency response and spatial resolution, minority carriers having tendency to accumulate in the vicinity of the output bias contact are instead rapidly swept out, being driven towards this contact by a concentrated electric field. To produce a local field concentration, the output bias contact may be extended towards the input bias contact, or the detector material near this contact may be configured by slotting or tapering.

Abstract: Conventional scanners used in thermal imagers scan the image along curved lines rather than straight lines, resulting in image curvature in the display. The invention eliminates this by processing the video signal from the scanner to compose an output video signal which represents scanning along straight lines (18) across the image. The output signal is composed of a number of successive portions (A to F) each derived from a different line or lines of the video signal provided by the scanner.

Abstract: A radiation scanning system is used with a radiation detector that has a predefined aperture stop. A first relay lens disposed to form a first image of the radiation detector a predefined distance from the aperture stop and a second relay lens is located a predetermined distance from the first relay lens and disposed to form a second image of the radiation detector onto a line scanning apparatus. The line scanning apparatus includes a rotor having a plurality of reflective planar facets disposed uniformly around its circumference. Each of the reflective planar facet has a normal substantially perpendicular to the axis of rotation of the rotor. The rotor is interposed between the second relay lens and the second image of the radiation detector and has its axis of rotation intersecting the optical axis of the second relay lens and disposed in such a way that as the rotor is rotated the second image is caused to move in a substantially circular locus.

Abstract: The system comprises a scanning telescope for scanning a field of view in a vertical direction. A detector array is positioned in the focal plane of the telescope for receiving radiant energy from the scanned image. The detector array comprises a plurality of elements which are positioned such that adjacent elements along the scan direction are offset with respect to each other. A processor receives output signals from each of the elements. The processor delays the signals received from leading elements in the array and adds these delayed signals to output signals from trailing elements in the array to form pseudodetector sums. Pseudodetector sums formed in this manner are geometrically filtered in a cross-scan direction and also filtered in the along scan direction.

Abstract: A radiation scanning system comprises scan mirrors optically coupled together by means of a spherical reflector to relay the scan mirror pupils through the optical path with minimal pupil shift for both wide and narrow field-of-view applications. The mirrors may oscillate at a predetermined fundamental frequency and a hamonic thereof to achieve near linear line scans or both line scan mirrors may oscillate at the predetermined fundamental frequency to achieve wider scan angles. In another embodiment, a line scan mirror is mounted on a multi-mode resonant scanner and phase lock oscillated at multiple frequencies while a second scan mirror functions as the field or line scanning element. In yet another embodiment, one line scan mirror is mounted on a non-turnable resonant scanner while a second scan mirror functions as the field scanning element.

Abstract: A thermal imaging system including a biassed elongate detector element of photoconductive material, over which an image of a thermal scene is scanned at a velocity that is matched to the drift velocity of photocarriers generated in the element. In order to improve responsivity and detectivity the length of the detector element or the magnitudes of bias and scan velocity are selected so that the time taken to scan the detector element from one end to a read-out region of the detector element is greater than the lifetime of the photocarriers generated in the element. In order to avoid loss of resolution by photocarrier diffusion the photocarrier lifetime of the detector material is of relatively low value. The system may include one detector element only, or it may include several detector elements arranged in parallel.

Abstract: A thermal wave imaging apparatus generates a real time image of the surface and subsurface of an opaque solid object. A.C. electrical signals indicative of the configuration of the surface and subsurface of the object which are generated during a thermal wave scan of the object by a first heating beam which generates a localized temperature gradient on the object and a deflectable second probe beam heating beam, which deflection is detected by a detection device mounted adjacent to the object, are stored in an image memory under the control of a central processor. A refresh counter generates sequential, incremental signals used to control the X and Y axis deflection of a display monitor. Such signals also address the image memory and generate output data controlling the intensity of the display point at each generated X and Y axis deflection point.

Abstract: An imaging sensor for scanning an image in an object space is disclosed. The imaging sensor comprises a first and second plurality of infrared detectors. Also provided is a reflecting means for reflecting a predetermined portion of the object space on the first plurality of infrared detectors during first portion of the scanning cycle. The reflecting means is further able to reflect the predetermined portion of the object space on the second plurality of infrared detectors during the second portion of the scanning cycle. In a further embodiment, the orientation of the detectors permits each of the detectors to be calibrated with respect to another of the detectors by a sequential comparison of the outputs of pairs of the detectors whose fields-of-view overlap.

Abstract: A thermal imager is provided with a signal processing circuit which compensates for differences in the sensitivities of the thermal detectors. The compensating circuit produces a signal dependent on the mean output of each detector over a predetermined period, stores the signal in a storage device at a frequency of not more than once each field and applies a correction signal derived from the storage device to the detector.

Abstract: In an earlier Specification there is described and claimed a surveillance arrangement suitable for use in an aircraft wherein a television camera/display combination provides an image of the viewed scene, and infra-red detector means viewing part of the same scene provides brighten-up signals to effect a localized increase in intensity of the displayed image to highlight heat emitting targets in that part of the viewed scene; the resultant display is ultimately made available to the pilot via a HUD screen. This arrangement is not always satisfactory, and the present invention seeks a better solution by arranging for a target-emphasising visual effect to be generated and projected onto the HUD screen quite separately of the view of the scene, whether that view is obtained directly (through the HUD screen) or indirectly (from an image projected onto the HUD screen).

Abstract: A method of locating potential oil and gas reservoirs in the earth utilizing a satellite equipped to receive reflected solar energy from the earth at at least one selected frequency band, transmitting signals indicative of the received reflected energy to the earth, recording the received signals in a manner to provide a map of the earth's surface, filtering the received signals to provide signals representative of bands characterized by hydrocarbon gas absorption of the solar energy, and displaying the filtered signals, the area of hydrocarbon absorption being indicated by low intensity levels. The satellite system can be equipped with a coherent infrared irradiation system which scans the area of obsrvation, utilizing a selected infrared wave length beam to augment normal solar radiation at those wave lengths most effective for detecting the hydrocarbon gas cloud which appears above an oil or gas reservoir.

Abstract: A compact stereoscopic thermographic IR viewing device is disclosed, which comprises a thermographic apparatus in front of which two binocular telescopes are arranged. One of the two telescopes images an IR scene in two intermediate images which differ slightly in perspective. These images are separated by stops on the detector of the thermographic apparatus so that an observer notes the scene in perspective through a second binocular telescope.

Abstract: A thermal-radiation imaging device comprises at least one semconductor body portion (10,20,30,40), e.g. of n-type cadmium mercury telluride, on which biasing-electrode means (1 to 4 and 4b to 44b), e.g. of gold, are spaced for causing a bias current predominantly of majority charge-carriers to flow along each strip (10,20,30,40). The bias current supports an ambipolar drift of radiation-generated charge carriers in the opposite direction. One or more read-out means (e.g. 11,21,51,41) is present in the drift path of each body portion (e.g. 10). The body portion (10,20,30,40) is present on a substrate 100 having a conductor pattern (61 to 64, 71 to 74, 81 to 84, 91 to 94) which provides electrical connections to each of the read-out means. Each read-out means which may be a diode junction or an electrode pair is formed at holes (reference a and b for an electrode pair) which extend through the thickness of the body portion (10,20,30,40) to the conductor pattern of the substrate (100).

Abstract: An arrangement for gating receivers of electro-magnetic energy where optical gating means are not available or not as advantageous as gating the detector array outputs. Appropriate passive and active discharge paths for the detecting elements are provided. Path isolation means are provided for interconnecting detector and memory elements. The gated receivers are applied to obtaining 3-D surface measurements based on the time of flight of a transmitted energy pulse.

Abstract: An improved thermal imaging device is provided herein, which includes an internally-mirrored autocollimating mirror, a multi-element detector and a diaphragm in the mirror for limiting the aperture of the multi-element detector. In the improved device the multi-element detector is offset from the optical axis. At a symmetrical point on the other side of the optical axis, at which the autocollimating mirror forms an image of the multi-element detector, a mirror is disposed. Such mirror project the image of the multi-element detector back to the autocollimating mirror. Such image is then reflected once more right way up and laterally unreversed onto the multi-element detector in such a way that each individual detector element receives its own image.

Abstract: A variable phase time delay and signal aggregation ssystem is disclosed. The invention is adapted for use in scanning detection system and serves to maintain spatial resolution on a target surface independent of scan angle. The invention includes means for detecting electromagnetic signals from the surface area. The detector means includes a plurality of detector elements. Each detector element generates a corresponding first plurality of output signals representative of the response of the detector to energy received from the surface area within the field of view of the detector as the detection system scans through a predetermined range. Control means are included for selectively clocking the output signals from the detector elements to phase the relative timing thereof as a function of the scan angle. Means are included to aggregate these signals to generate a combined output signal having the predetermined spatial resolution.

Abstract: Scanning imagers often comprise a plurality of detector elements which may be scanned in swathes to produce an image. To match the offsets or sensitivities of such elements the mean values of the channels adjacent each swathe boundary are compared, and an error signal produced which is fed back to equalize the values across each boundary. Proportionally smaller corrections are applied to the intermediate channels in each swathe. In this way the swathing or banding effect often associated with such imagers is much reduced.

Abstract: An anamorphic optical system for use in a thermal imager with a sprite detector includes two or more optical elements, preferably prisms, which are shaped and positioned so that change in their refractive index with temperature and/or wavelength results in a lateral shifting of the output energy substantially without any change in direction. The energy passes through a focussing lens to the detector. As a result, the lateral shifting of the energy output by the anamorphic system does not affect the position of the image on the detector. This compensates for the effect of variations in refractive index of the materials of which the prisms are made, as a function of wavelength and/or temperature.

Abstract: A thermal imaging system is disclosed in which infrared radiation from the viewed scene is transmitted to a two-dimensional detector array carried on the focal plane of an optical/electronics module which has embedded in it amplifying, filtering and multiplexing circuitry utilizing MOSFET transistors. The module is located inside the cooling device. Cooling requirements depend on the alternatives (a) of using detectors responsive to wavelengths in the 3.0 to 5.0 micron range, which require less cooling, or (b) of using detectors responsive to wavelengths in the 8.0 to 12.0 micron range, which require liquid nitrogen cooling. The two-dimensional detector array may be combined with a limited scanning, called "nutation", which causes each detector to view a plurality of pixels in the incoming infrared radiation.

Abstract: Aiming system for firearms of the type for use when a target is obscured for example by darkness or camouflage include a sighting arrangement which comprises an imaging device of sufficiently small size to be carried on the firearm. These imaging devices consequently have small apertures and low resolution and are therefore of limited value. The aiming system disclosed herein has an imaging device remote from the firearm which forms a background image of a given field-of-view, the image being displayed on a screen. The system includes a second imaging device carried by the firearm and having a smaller field-of-view corresponding to the line-of-sight of the firearm. The images produced by both imaging devices are correlated by a correlator and a sight-mark is generated in the background image to indicate the line-of-sight of the firearm when correlation is obtained.

Abstract: Bias current to an array of detectors is switched off during periods when the detectors are fruitlessly receiving energy from inside the image housing to either side of an optical aperture thereof. This reduces the generation of heat in the detectors.

Abstract: The disclosed charge transfer signal processor includes a vacuum housing having an input face and a output face, a 2-D electromagnetic input means cooperative with said input face for providing a 2-D input electronic charge signal within the vacuum housing, transfer means for imaging the 2-D input electronic charge signal in a region of the vacuum housing proximate the vacuum housing output face, and charge feedthrough means coupled to the vacuum housing output face for transferring the imaged 2-D electronic charge signal externally to the vacuum housing. In one embodiment, the charge transfer signal processor is operable as a Gen-I charge transfer amplifier. In another embodiment, a microchannel plate assembly is dThis invention was made with Government support under Contract F19628-84-C-0048 awarded by the Department of the Air Force. The government has certain rights in the invention.

Abstract: A system for inspecting the electronic integrity of solder joints by repetitive pulse-heating the solder joints with radiant energy and determining the temperature oscillation of pulse-heated solder joints by measuring the infrared emissions from the solder joints during heating and non-heating periods. Advantageously, the exposed solder joints of a circuit board can be tested all at one time by pulse-heating the entire circuit board. The temperature oscillation of each joint can be compared to the temperature oscillations of corresponding standard solder joints of known good electronic integrity on properly operating boards.

Abstract: The apparatus comprises a radiation-sensitive detector (17) and optical means for directing radiation from an observed field of view on to the detector. The optical means includes a rotatable support member (10) rotatable about an axis (11) and carrying a number of reflecting members (12) equally-spaced around it. Each reflecting member (12) is located in a plane parallel to the axis (11) of the support member and each is arranged at the same non-perpendicular angle to a radius of the support member. A pivoted reflecting member (14) is located inside the locus of the plurality of reflecting members (12) and is rotatable about an axis (15) located in a plane perpendicular to that axis (15). In operation radiation from the field of view is reflected by the pivoted reflecting member (14) on to successive ones of the rotating reflecting members (12) and thence on to the detector (17).

Abstract: The camera includes a chip of infrared detectors disposed in lines and a processing chip. The latter comprises integrators for integrating the output currents of the detectors, controlled by an automatic gain control loop for reducing the dynamic of the signal, delay lines, a summator for each line of detectors, error correction devices for reducing the fixed spatial noise errors, and a multiplexer receiving the signals associated with the various lines of detectors and furnishing a signal to a display device.

Abstract: Disclosed is a system for passive and active optical-mechanical scanning of a visual field. A passive channel uses a thermal imaging system scanning in two coordinates and an active channel uses a laser beam which is deflected in two coordinates. During scanning in the active and passive channel specific phase relations are maintained. The system according to the invention represents a device for passive and active scanning of a visual field which works with low transmitting power and in which the mutual interference of active and passive channels is prevented. The system can be used particularly for steering (active channel) of flying bodies or for the control of machines or devices over certain distances.

Abstract: In an apparatus for generating an image of a scene, preferably an image of a heat image, the image is moved line by line across a row of detectors by means of a scanning mirror. The signals thus generated control light-emitting elements via amplifiers. The light-emitting elements are also disposed in a row, and their light is also guided via the scanning mirror. The scanning of the image is done bidirectionally, that is, during the forward pass and return pass of the scanning mirror. For correction of the resultant phase error, which is brought about by a delayed triggering of the light-emitting elements, an optical deflector element is provided which can assume two defined positions. The first position is associated with the forward pass of the scanning mirror and the second position is associated with its return pass and these positions are entirely independent of the location of the scanning lines.

Abstract: A twin polygon thermal imager is provided with a compensator for compensating for horizontal distortion in the image produced on a CRT. The distortion compensator applies an amount of correction which is determined, in each horizontal line, to compensate for the particular magnitude of the distortion in that line. The amount of correction needed is determined as a function of the angle between the rotational axis of the polygons and the particular facets thereof producing the particular video line. Compensation is achieved by adjusting the timing and the frequency at which digital video data is read-out from a signal store.

Abstract: An arrangement for the multispectral imaging of objects, preferably targets, including an optical system for imaging the object dots of the objects on at least one charge-coupled semiconductor element, with each charge-coupled semiconductor element including a plurality of light sensitive individual detectors and a charge-transfer circuit arrangement connected to said detectors. The plurality of individual detectors includes at least two groups of detectors with each group being sensitive to light energy of a different wavelength or wavelength range. The groups of detectors are disposed on the surface of the semiconductor element such that the optical system, due to its scatter circle, images each object dot on at least one detector of each group, and the output signals of each individual detectors are fed to the charge-transfer circuit arrangement of the semiconductor element.

Abstract: A scanning infrared sensor scans an array of detector elements across a field of view and samples the detector elements at a predetermined rate. The detector elements are sampled with a common sample frequency and with predetermined time phase values, are processed through delay elements such that the delayed detector output signal values are out of time phase, and are supplied to a multiplexer. The multiplexer produces a series of discrete signals at equal time intervals having an effective sample rate which is a multiple of the individual detector element sample rate, thereby reducing the complexity of processing circuitry, the number of interconnections required between the focal plane array and on-gimbal circuitry, and the size and weight of delay elements.