Abstract: An apparatus for measuring the delay time interval between electrical pulse signals, particularly in conjunction with electrooptical range finders. A coarse measuring counter counts clock pulses from a quartz oscillator during the interval and a fine measuring interpolator determines the residual time from the end of the interval to the next clock pulse. Residual time at the start of the measuring interval is avoided by exactly synchronizating the start of measurement with a timing pulse front (n+2) of the quartz oscillator.

Abstract: A laser weapon which has no boresighting problems in that only one laser is sed to perform all the functions of search, track, and negation. The laser weapon is made to operate in both a low power cw mode and a high energy pulsed mode about the boresight. This is accomplished here by the application of a material which can be rapidly switched from a transmissive to a reflective state so as to be able to utilize the same laser for search, travel, and negation; thus eliminating the need for boresight and requiring only alignment.

Abstract: Passive target detectors which employ infra-red sensors may have difficulty in distinguishing between a cool target near the detector and a warmer one further away.A detector detects a source of infra-red radiation and if its size indicates that it may be of interest, a point source detector operates a gate to allow information regarding the direction of the target to be transmitted to a store and to a calculator.This information is combined in the calculator with stored directional information from the previous scan to give the range of the source. The real intensity of the source is then calculated from its range and apparent intensity. If the real intensity indicates that the target is of interest, an alarm or other indication may be operated.

Abstract: A digital code reader reads the digital key code in a scrambled video signal. The key code represents the scheme used to scramble the signal before broadcasting and is used by the video receiver to unscramble the received signal. To prevent misreading of the key code due to interference such as ghost signals, the reader uses a predetermined property established for the broadcast signal. The change in that property caused by interference in the received signal is determined and a control signal is generated from that determination. A threshold signal is used to reproduce the key code from the received signal by comparison of the levels of the received signal with the level of the threshold signal. The level of the threshold signal is set by the control signal, which depends on the change detected in the predetermined property of the broadcast signal. Thus the level of the threshold signal can be set to enable the reproduced digital information to match the broadcast digital information.

Abstract: The receiver (3') of a laser range finder operating on the pulse propagation and including a transmitter unit (1) and a first receiver unit (2) is sampled by a spike pulse (5) derived from the transmitter pulse in such a way as to produce a low-frequency representation (10). The non-linearity of the phase modulation of this spike pulse, which is detrimental in very accurate measurements taken over long distances, is eliminated in that the oscillations of high-frequency oscillator (8) are supplied to a second receiver unit (2') in which they are scanned by the same spike pulse (5) and are then also suitably transformed into a low-frequency representation (10'). A counter (12) then counts the low-frequency zero-passages of the oscillator, beginning with the onset of the low-frequency cycle, thereby eliminating all errors (FIG. 1).

Abstract: A device for detecting a sunbeam incident angle comprises at least one pair of solar cells disposed to be perpendicular to each other, wherein the short-circuit currents flowing in the respective solar cells in the pair are detected, a relative ratio between the detected short circuit-currents is computed, and the sunbeam incident angle is detected on the basis of that relative ratio.

Abstract: An analyzer for determining the frequency of short bursts of radiation is disclosed. An input signal burst is fed to groups of filters and the filter in each group producing the largest output signal is identified. The frequency response characteristics of the filters identified, as well as the magnitudes of their output signals, are utilized in computation of the frequency of the input signal burst.

Abstract: A method and apparatus for determining distance from a bow to a target at which the bow is aimed in which a beam of collimated light from a laser is directed to the target and reflected to a linear photosensitive element mounted on the bow. The element and laser are positioned on the bow so that the linear position of the incident reflected beam varies with the target distance and the element produces an output indicating the position. A circuit receives that output and produces a display of the target distance.

Abstract: A subscriber cable television system using predominantly digital signal processing techniques employs an improved time-warp and segment scrambling method for providing extremely high security. Means are also disclosed for suppressing the undesirable effects of discontinuities in the scrambled video signal by methods of inserting additional data samples between adjacent continuous segments, and by dithering the video line positions of the discontinuities. Preferably the scrambler and descrambler each have a memory for storing video samples, first and second address counters for providing read and write addresses to the memory, and means for decrementing or inhibiting address counting during the time between segments of continuous video samples in order to insert and delete samples during scrambling and descrambling, respectively.

Abstract: A system for viewing a lighted scene through a diffusive medium, such as rain, fog, snow, blowing dust, or sand, by overcoming the effects of light backscatter. The system uses a flash lamp which operates in response to short electric pulses at a high repetition rate to give the appearance of continuous illumination. The scene is viewed through a panel which operates as a high-speed optical shutter. The panel serves to block the reflected light (backscatter) from the nearby particles of the diffusive medium and passes the reflected light from the distant objects which make up the scene.

Abstract: A method and apparatus associated therewith for acquiring and maintaining a high quality communication by communication means of the type that includes a detector and focusing means for directing encoded incoming radiation to said detector. Means are provided for determining the location of said radiation upon said detector and for generating an electrical signal responsive to said location. Said electrical signal is applied to electroluminescent means so that there is produced for the user a pattern of illumination indicating the degree of alignment of said communication means with the incoming radiation.

Abstract: An instrument for measuring the distance of a body in relative motion away from a datum point measures the optical attenuation of an optical fibre that has an end secured to that datum and extends to the body where the remainder of the fibre is coiled. As the body moves away, so progressively more fibre is uncoiled, and the contribution of bending losses to the total loss is reduced and hence the resulting reduction in attenuation provides a measure of distance travelled.

Abstract: The invention comprises a system for scrambling, transmitting and descrambling the video portion of a TV signal. In the preferred embodiment two serial memories (charge coupled devices) are utilized to store data representing selected portions of the video to be scrambled. The charge coupled devices are selectively clocked to interchange portions of video, with the point at which the interchange occurs determined by a code pattern generator and changing in a predetermined manner. The point of interchange is updated or changed as determined by a code pattern generator and changing every three lines of the TV signal. Descrambling is accomplished by an identical hardware arrangement with the exception that the code pattern generator at the descrambler is synchronized with the code pattern generator in the scrambler. Synchronizing information can be transmitted to the descrambler in any convenient fashion including inserting the data in an unused video line of the vertical retrace interval.

Abstract: A distance measuring apparatus for automatically measuring a distance from a reference point to a subject of interest, such as a subject to be photographed, is provided. The present apparatus includes a position sensitive detector having a photoelectric surface defined between two extreme points. Thus, when a light pulse emitted from the apparatus is reflected by the subject and impinges upon the photoelectric surrface, there is produced a pair of current signals, which are then processed to obtain a distance signal indicating the distance to be measured. Thus, the present apparatus can provide a highly accurate measurement.

Abstract: A train of incoming data words, specifically digitized video samples arrayed in frames of Y lines of X pixels each which have already undergone a 2-dimensional spatial transformation, is scrambled by being divided into Z sequences (frames) whose data words are temporarily written in respective cells of Z.sup.2 storage units of a memory of dynamic-RAM Type. The Z.sup.2 storage units, each divided into Z sections, are read out in cyclic-succession--at a rate of one cell per unit--and each cell is reloaded immediately after being vacated. Reading and writing occurs for one set of Z sequences in a first addressing mode, conforming to the order of arrival of the data words in the incoming train, and for the next set in a second addressing mode involving the grouping of homologous data words of respective sequences into successive series of Z data words each.

Abstract: The laser source energy and the target source energy goes through a common ptical path to a beam splitter. The energy from the target source is filtered, allowing only the laser information to pass through to the laser quadrant detector. The second path from the beam splitter has a blocking filter to block the laser energy, and the remaining energy, that of the target source, is measured by the target quadrant detector. The geometric translator is a computer controlled azimuth and elevation gymbal device which tracks (drivers to null) the target source. The target source is a strobe lamp. The angular information from the dual quadrant detectors and the geometic translator are fed into an compact mini-computer.

Abstract: An optical instrument (10), such as a stability monitor or a target range finder, uses an unstabilized laser (12) to project a composite optical signal of coherent light having two naturally occurring longitudinal mode components. A beamsplitter (24) divides the signal into a reference beam (26) which is directed toward one photodetector (28) and a transmitted beam (42) which illuminates and is reflected from a distant target (44) onto a second photodetector (52) optically isolated from the first photodetector. Both photodetectors are operated on the square law principle to provide electrical signals modulated at a frequency equal to the separation between the frequencies of the two longitudinal mode components of the optical signal projected by the laser (12).

Abstract: Parts of a composite video signal, such as segments of each horizontal scan line, are stored in analog storage devices and retrieved therefrom in a cyclic manner to rearrange them and thereby encode the signal. The cyclic retrieval of the information from the storage devices is carried out on a selective basis in accordance with the binary state of a pseudo-random signal that is generated independently at each of the encoding and decoding stations. Synchronization of the two independently generated signals is provided by a control word and an initialization word that are transmitted with the encoded video signal, one of which is encrypted. Decryption of the word is carried out with a master key at each of the encoding and decoding stations.

Abstract: A scrambling system for an audio frequency signal in which an audio signal is divided into blocks, each block being formed of a plurality of frames, the plurality of frames are rearranged on a timebase in a predetermined order at every block so as to be encoded and the encoded signal is re-arranged on the timebase in an original order so as to be decoded, in which there are provided a first signal processing circuit for inserting a redundant portion into a portion between adjoining frames and timebase-compressing the frames in response to the redundant portions upon encoding, a control signal generating circuit for inserting a control signal other than an audio information into the redundant portions, a control signal detecting circuit for detecting the control signal upon decoding and a second signal processing circuit for removing the redundant portions in synchronism with the detected control signal and timebase-expanding the frames in response to the redundant portions.

Abstract: A static noninverting driver circuit is used with a standard static address-row-decoder circuit in order to provide capacitance load drive capability and relatively high-speed operation. The driver circuit uses n-channel enhancement and depletion mode field effect transistors and a feedback bootstrap capacitor to achieve low power-high speed operation with a full VDD output high level.