Abstract: A television signal distribution system protects outgoing programs from unauthorized reception; and marks or tags the conveyed signals with a digital word identifying the class of viewers authorized to receive the program ("level of service"). Basic encription is accomplished by effectively suppressing the horizontal and vertical synchronizing information. Horizontal sync information, and the program-characterizing level of service word which is interleaved in time with prescribed horizontal sync pulses, is distributed via pulse amplitude modulation of the audio carrier.At subscriber receiving stations, the sound carrier amplitude modulation is recovered to permit level of service authorization verification; and to reconstitute the video carrier to receivable form by an amplitude modulation which is the inverse of the sync-suppressing modulation of the head end.

Abstract: A method for scrambling a television signal for use with a multiplexed analog component (MAC) format employs a three digital bit code for each horizontal line of the picture. The bits identify the position of the luminance and chrominance information of the signal for every line of the television picture and whether the information is to be scanned from left to right or right to left.

Abstract: A scrambling system of television signal includes a circuit for eliminating vertical sync pulses in a vertical sync pulse period and equivalent pulses in first and second equivalent pulse periods at opposite ends of said vertical sync pulse period. In place of the eliminated pulses, substitute pulses having a frequency equal to an integer times the frequency of horizontal sync pulses are deposited. A framing code inserting circuit is provided for inserting at least one framing code in the substituted pulses. The framing code is carrying information how the television signal is scrambled.

Abstract: Apparatus is provided for determining the relationship between a vehicle's thrust line and the vehicle's body center line. A movable light source is located externally of and independent of the vehicle and serves to establish a pair of reference light beams falling in parallel planes and which are spaced apart sufficient to permit a vehicle to be positioned longitudinally therebetween. The vehicle's thrust direction is determined by mounting sensors on the nonsteerable wheels so as to extend transversely away from the vehicle's body to intercept the light beams, together with circuitry for providing output indications dependent upon the location of light interception and which indications are representative of the vehicle thrust direction. The body center line is determined by employing targets which are mounted to body sides of the vehicle to intercept reference light beams.

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: 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 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: 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 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: 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.

Abstract: Helium-3 and helium-4 bombardment of InP over a fluence range of 10.sup.11 to 10.sup.16 ions/cm.sup.2 reproducibly forms highly resistive regions in both p-type and n-type single crystal material. Average peak resistivities are about 10.sup.9 ohm-cm for p-type InP and are about 10.sup.3 ohm-cm for n-type InP. High resistivity has also been produced in GaP, GaSb, GaAs, and InGaAs by helium bombardment. Stripe geometry lasers and planar photodiodes which incorporate helium-bombarded zones are described.