Abstract: A television receiver for receiving standard television channel signals and a scrambled television channel signal includes a channel selector which selects one of the television channel signals, a tuner which tunes the selected television channel signal, and a converting circuit which converts the scrambled television channel signal to a vacant standard television channel signal for tuning by the tuner.

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: A laser radar system employs an acousto-optic modulator to sweep an output beam. Comparison of reflected radiation with output radiation permits adaptive control of steering angle and beam width to track a target with efficient use of power.

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: In a pay television channel selector, a reception contract selecting portion comprises parallel circuits which are disposed in correspondence with channels and whose impedances are made different between the contracted and uncontracted channels, and a control circuit device whose output level changes depending upon the impedances of the parallel circuits, so that the scrambled broadcast of the contracted channel is descrambled on the basis of the output control signal of the control circuit device. The tapping of the uncontracted channel ascribable to the imperfection of a double lock preventive mechanism of multi-throw switches used as channel selecting switches can be prevented.

Abstract: In an optical radar system a coherent signal is transmitted at a variable position and the return signal, that is, the reflected portion of the coherent signal is received and coherently detected. The transmitter utilizes a scanning laser having an electron beam that impinges upon a variable reflectance mirror that terminates one end of an optical cavity. An oscillating mode is generated within the resonant cavity when the electron beam locally heats the surface of the variable reflectance mirror to create a pixel that reflects light in a diffracted pattern. The receiver utilizes a stable single mode laser to illuminate a variable reflectance surface. A receiver electron beam generates a plurality of receiver pixels at various positions. The diffracted light from each pixel generates a plurality of variable angle local oscillator beams that are summed with the return signal at a beamsplitter. The output of the beamsplitter is applied to the surface of a detector array.

Abstract: In an optical radar system a coherent signal is transmitted at a variable position and the return signal, that is, the reflected portion of the coherent signal is received and coherently detected. The transmitter utilizes a scanning laser having an electron beam that impinges upon a variable reflectance mirror that terminates one end of an optical cavity. An oscillating mode is generated within the resonant cavity when the electron beam locally heats the surface of the variable reflectance mirror to create a pixel that reflects light in a diffracted pattern. The receiver utilizes a stable single mode laser to illuminate a variable reflectance surface. A receiver electron beam generates a plurality of receiver pixels at various positions. The diffracted light from each pixel generates a plurality of variable angle local oscillator beams that are summed with the return signal at a beamsplitter. The output of the beamsplitter is applied to the surface of a detector array.

Abstract: In a distance measuring apparatus in accordance with the present invention, a light beam of a wide solid angle is projected on a photographic object by means of a strobo light source, and reflected rays are received by a photoelectric device array which has a predetermined number of photoelectric devices each with narrow directivity which are comparable to solid angles necessary to see the object from the photoelectric devices disposed with their optical axes at predetermined angular pitches. When the output of a photoelectric device, which is issuing maximum amplitude output, is selected by means of a maximum value detector circuit, and a distance signal is discriminated from background noises such as sun light or electric illumination light by passing through a differentiating circuit, and then being processed by a function circuit and fed to a lens driving system or indicator.

Abstract: A terrain-contour-matching guidance method is disclosed in which topographic reference data are made to include the same systematic errors which altitude measurement of an unmanned flight is expected to produce. Speed/course and general flight path tracking is operated on a higher resolution.

Abstract: A distance measuring apparatus projects a light beam toward an object whose distance is to be determined. Reflected light from the object is divided into a pair of light components by a beam splitter. The intensity of one of the light components is detected by first light intensity detector. The other light component is subject to an alteration in intensity in accordance with an angle formed between the illuminating light and the reflected light, and the intensity of the said other light component is detected by second light intensity detector. The outputs from both detector is fed to a circuit, which derives information indicative of a distance to the object being determined.

Abstract: A subscription television system includes a head-end for transmitting selected fields of a television signal in a scrambled form, the scrambled fields being identified by an encrypted mode control code inserted in a selected horizontal line of the preceding vertical interval. The mode control code is formed such that a predetermined non-transmitted control code is realized when the mode control code is processed with vertical interval system control data according to a selected function. A decoder processes the received mode control code and system control data according to the selected function to reconstitute the predetermined control code for enabling unscrambling of the following field. The decoder may employ majority voting techniques whereby not all of the bits of the reconstituted control code need be properly recovered to enable the unscrambling function.

Abstract: A system for scrambling a video signal that includes a vertical blanking interval of equalizing pulses spaced at half line intervals followed by serrations which are, in turn, followed by equalizing pulses spaced at half-line intervals and thereafter by horizontal pulses spaced from each other at intervals of two half-lines each. The scrambling includes (a) providing an unsuppressed interval in each field which extends through the first horizontal sync pulse preceded by a two half-line space and (b) suppressing horizontal sync pulses occurring after the first horizontal sync pulse preceded by a two half-line space.

Abstract: An improvement to a laser ceilometer and like instruments comprises a laser diode array which includes a plurality of laser diodes, and an array driver driving the laser diode array in accordance with commands from a microprocessor. The laser diodes are GaAs diodes. By utilizing the improvement, service life and reliability of the ceilometer are both increased.

Abstract: Active distance detection is effected by (1) directing light through a lens to an object, from an emitter zone located at or proximate the lens focal plane, (2) sensing the amplitude of light reflected back through the lens from the object at two or more detection zones that are located respectively at different distances from the emitter zone and that are generally coplanar with the emitter zone in a plane substantially normal to the optical axis of the lens, and (3) comparing the amplitudes of object-reflected light at the detection zones in a manner determinative of the unique distance-from-emitter-zone versus reflected-light-amplitude curve of the object's distance.

Abstract: Apparatus is disclosed for measuring the distance to a point on the inner wall of a hot furnace.

Abstract: A uniquely configured radiation fringe velocimeter is used to measure all three components of velocity remotely from a single point. The device is particularly intended for utilization aboard an aircraft, in which case the velocity being measured may be that of aerosol particles or other scattering centers in the free airstream at a location spaced apart from the surface of the aircraft and thus for the most part, free from any associated turbulence effects, etc.

Abstract: A short-ranging laser system having an improved pulser which includes a drive pulse signal generator and a driver. The drive pulse signal generator is essentially a triggered bipolar avalanche transistor that outputs a drive pulse signal through a voltage shifting circuit to the driver. The driver is essentially two parallel-connected power MOSFETs that output a driver pulse to a GaAs heterojunction laser diode. By circuit design, the deadtime plateau is substantially reduced so that the laser return energy homodynes with the still active laser to produce a detectable output for a target within 5 meters.

Abstract: The invention relates to an optical arrangement for a range-finder having an observation path of beams and a measuring path of beams constituted of an objective and a reflection system arranged in the near-axial room behind and in close contact to the objective. The reflection system is laterally displaced in parallel to the objective axis and has a second reflecting face at right angles to the optical axis and a first reflecting face inclined by 45.degree. relative to the optical axis, the extension of the latter at right angles to the optical axis is smaller than the corresponding extension of the second reflecting face.

Abstract: Apparatus (20) provides a stable optical reference in the presence of optical source jitter. It comprises a beamsplitter cube (21) having an input surface 22, an output surface 23, a totally reflecting surface (24), and a partially reflecting diagonal surface (26) with a corner cube 27 disposed on a surface (25) opposite to the input surface. An input beam (30) applied to the beamsplitter cube results in two output beams (33, 33'), coplanar with an output optical axis (31), if the input beam deviates at 32 from an input optical axis. The two output beams deviate equally but oppositely from the output axis. This provides signals from which a stable output optical axis may be determined. A polarization-sensitive embodiment is also disclosed which eliminates problems associated with the use of coherent light sources.

Abstract: An automatic homing system for a subscription television signal decoder comprises a tuning system responsive to a decoder off-command signal for operation in a search mode wherein successive television channels are sequentially tuned until a subscription television signal is detected. As a result, the memory circuits of the decoder may be refreshed with updated subscriber authorization data in response to a transmitted subscription television signal even though the decoder is turned off.