Abstract: Two mutually coherent light beams (50, 58) formed, for example, from a single monochromatic light source (32) are directed to a reflecting surface (20) of a rotatable object (18), such as a mirror, where they are reflected into imaging optical lens (10) having a focal plane optically at infinity whereby a series of interference fringes (14) will be formed in the focal plane (12) which will translate linearly thereacross in response to angular rotation of the object. Photodetectors (22, 24) are located adjacent the focal plane to detect the fringe translation and outputs a signal in response thereto which is fed to a signal processor (30) which is adapted to count the number of fringes detected and develop therefrom a measure of the angular rotation and direction of the object.

Abstract: During a distress call, a distress location transmitter 10 generates a high frequency carrier signal 40 that is modulated by a predetermined distress waveform characteristic 29. The classification of user associated with the distress call is identified by periodically interrupting modulation 42; user classification is determined by the repetition rate of the interruptions, the interruption periods, or both.

Abstract: A long lifetime Stirling cycle cryogenic cooler particularly adapted for space applications comprised of a compressor section (10) centrally aligned end to end with an expansion section (12) and respectively including a reciprocating compressor piston (14) and displacer (16) radially suspended in interconnecting cylindrical housings (18, 20) by active magnetic bearings (26, 28, 30, 32) and having adjacent reduced clearance regions (82, 84, 108) so as to be in non-contacting relationship therewith and wherein one or more of these regions operate as clearance seals. The piston (14) and displacer (16) are reciprocated in their housings (18, 20) by linear drive motors (48, 52) to vary the volume of respectively adjacent compression and expansion spaces (44, 46) which contain a gaseous working fluid and a thermal regenerator (95) to effect Stirling cycle cryogenic cooling.

Abstract: A linear magnetic bearing includes a stator member (16) stationary relative to x, y and z axes and having a longitudinal axis on the z axis as well as a member (15) longitudinally translatable relative to said axes. The translatable member (15) is controlled to have a longitudinal axis coincident with the z axis. Permanent magnets (36 and 37) on one of the members positions the translatable member (15) in a plane defined by the x-y axes relative to the stationary member (16). The position of the translatable member (15) is sensed by sensors (41 and 42) relative to the stationary member (16) in the plane defined by the x-y axes. Electro-magnets (38 and 39) on one member (23) responds to the sensor (41 and 42) to center the longitudinal axis of the translatable member (15) on the z axis. First low reluctance magnetic flux paths for the permanent magnets (36 and 37) exist through both of the members and a radial air gap (32, 33, 34 and 35) between the members.

Abstract: In a method of and apparatus for damping nutation of a spinning spacecraft (10), spin axis attitude disturbances are substantially reduced by controlling at least one nutation damping gas thruster (18) to fire with non-uniform gas pulses. During the beginning of a nutation control sequence, the duration of successive gas pulses is gradually increased (up pulsed) from zero to a predetermined maximum duration. The duration of successive pulses is then maintained constant for a time period. Finally, at the end of the nutation control sequence, the duration of successive gas pulses is gradually reduced to zero (down pulsed). Up pulsing of the gas thruster (18) is initiated in response to a predetermined maximum nutation angle measured by an accelerometer (20). Down pulsing of the thruster (18) is initiated in response to a predetermined minimum nutation angle. The number of variable and constant duration gas pulses delivered by the thruster (18) depends upon the mass distribution of the spacecraft (10).

Abstract: An apparatus for processing multidimensional data with strong spatial characteristics, such as raw image data, characterized by a large number of parallel data streams in an ordered array, comprises a large number (e.g. 16,384 in a 128.times.128 array) of parallel processing elements operating simultaneously and independently on single bit slices of a corresponding array of incoming data streams under control of a single set of instructions. Each of the processing elements comprises a bidirectional data bus in communication with a register for storing single bit slices together with a random access memory unit and associated circuitry, including a binary counter/shift register device, for performing logical and arithmetical computations on the bit slices, and an I/O unit for interfacing the bidirectional data bus with the data stream source.

Abstract: The corrosive alkaline surface layer of an epoxy resin product formed by the curing of the epoxy with an aliphatic amine is eliminated by first applying a non-solvent to remove most or all of the free unreacted amine and then applying a layer of a chemical reagent to neutralize the unused amine or amine functional groups by forming a substituted urea. The surface then may be rinsed with acetone and then with alcohol. The non-solvent may be an alcohol. The neutralizing chemical reagent is a mono-isocyanate or a mono-isothiocyanate. Preferred is an aromatic mono-isocyanate such as phenyl isocyanate, nitrophenyl isocyanate and naplthyl isocyanate.

Abstract: A special purpose optical collimator system which generates multiple collimated light beams, with precisely related angular separation of the beams. The system is comprised of a stack of relatively flat plate-like refracted prisms (10.sub.1, 10.sub.2 . . . 10.sub.15) in the form of wedges, each having a specified angular deviation, mounted on top of one another in a fixture (44) which holds the wedges so that they are adapted to operate at minimum angular deviation and thus are relatively insensitive to rotational and angular charges. A collimated source of monochromatic light generated for example by a helium-neon laser (20) and a collimated beam expander (24, 30 and 54) provides a common incident beam (14) to the wedges whereupon a plurality of, for example, equally spaced emergent beams (12.sub.1, 12.sub.2 . . . 12.sub.15) are provided.

Abstract: A low intensity X-ray and gamma-ray spectrometer 10 is disclosed for imaging, counting, and energy resolving of single invisible radiation particles. Spectrometer 10 includes a converting device 20 for converting single invisible radiation particles to visible light photons. Another converting device 24 converts the visible light photons to photoelectrons. A fiber optics coupling device 22 couples together converting devices 20 and 24. An intensifying device 26 intensifies the photoelectrons by an average gain factor of substantially 10.sup.4 -10.sup.7. Intensifying device 26 is an anti-ion feedback microchannel plate amplifier which is operated substantially below saturation. A displaying device 32 displays the intensified photoelectrons. Displaying device 32 indicates the spatial position, number, and energy of the incoming single invisible radiation particles.

Abstract: A machine is disclosed for cleaving hard crystals (40), a typical example of which is lithium fluoride, with precision and uniformity and includes vertical axis positioning control means (12) for an adjustable spring tension guided hammer mechanism (17, 18) employed to strike an anvil (21) and thereby generate a crystal cleaving shock wave transmitted to a cleaving blade (23) having an angulated cleaving edge 24 in contact with one corner of the crystal (40). Connection between the anvil 21 and the blade is by means of a pair of vertical shafts (20) held in substantially friction free engagement by two pairs of adjustable linear bearings (19). An underlying crystal holding fixture (38) with horizontal position control means (14) includes a zero reference stop face (42) for the crystal (40) and opposing spring-loaded clamping and vertical positioning elements (43, 44) which are precisely guided.

Abstract: A transformer (20) for coupling AC electrical energy from a stationary element (22) to a rotating element (24) without the use of sliding contacts. The transformer (20) is of the rotary type and includes a ferrite core (39) and two primary windings (70 and 72) which are stationary with respect to a secondary winding (88) which rotates within an annular cavity (48) adjacent an axial bore (58) in the core. The core (39) is comprised of two cup type core halves (40 and 42). Electrical connection to the secondary winding (88) is made through a split bobbin assembly (89) which couples to a coaxial shaft assembly (59) located in the axial bore (58). The electrical coupling to the coaxial shaft assembly is made through a continuous transverse channel (68) connecting the axial bore (58) with the annular cavity (48). The transverse channel (68) forms a single air gap; however, it is not open directly to free space but is shielded by the magnetic permeable material of the core halves (40 and 42).

Abstract: A fully implantable and self-contained device is disclosed composed of a flexible electrode array 10 for surrounding damaged nerves and a signal generator 12 for driving the electrode array with periodic electrical impulses of nanoampere magnitude to induce regeneration of the damaged nerves.

Abstract: A microwave switching power divider for selectively dividing and switching microwave energy among a plurality of outputs to other microwave devices includes a pair of parallel, spaced-apart circular ground planes defining a microwave cavity with multi-port microwave power distributing switching circuitry formed on opposite sides of a thin circular dielectric substrate disposed beween the ground planes. The power distributing circuitry includes a conductive disk located at the center of the substrate and connected to a source of microwave energy. A plurality of tapered radial power dividing transmission lines for intercepting the standing waves are symmetrically disposed about and connected to the conductive disk. Within each line, a high speed, low insertion loss switching diode and a DC blocking capacitor are connected in series between the outer end of a transmission line and an output port.

Abstract: The memory-based frame synchronizer comprises a serial-to-parallel converter which converts a serial input data stream to a constantly changing parallel data output. This parallel data output is supplied to programmable sync word recognizers each consisting of a multiplexer (18, 20, 22) and a random access memory (RAM) (38, 40, 42). The multiplexer is connected to both the parallel data output and an address bus (24) which may be connected to a microprocessor or computer for purposes of programming the sync word recognizer. The RAM is used as an associative memory or decoder and is programmed with the pattern of binary 1's and 0's necessary to identify a specific sync word. The RAM produces an output when the address supplied by the multiplexer corresponds to the specific sync word. Additional RAMs (62, 76, 78) are used as counter decoders to define word bit length, frame word length, and paragraph frame length.

Abstract: A low thrust monopropellant engine having a conventional body and nozzle configuration wherein the monopropellant fuel is fed into the thruster with dual injection tubes via an injector shell with dual spray jets formed therein. The spray jets are positioned generally opposed to each other. A heater-screen pack combination thermally decomposes the fuel after injection into the combustion chamber of the thruster.

Abstract: An imaging system comprising a multi-channel matrix array of CCD devices wherein a plurality of sensor cells (pixels) in each channel are subdivided and operated in discrete intercoupled groups or subarrays with a readout CCD shift register terminating each end of the channels. Clock voltages are applied to the subarrays and are manipulated to selectively cause charge signal flow in each subarray in either direction independent of the other subarrays. More particularly, the array is divided into six independent subarrays, three on each side of the array, such that each channel common to three subarrays is divided into three sections of three sensor cells each. By selective application of four phase clock voltages, either one, two or all three of the sections cause charge signal flow in one direction, while the remainder cause charge signal flow in the opposite direction.

Abstract: The position of a terrestrial RF source is determined from a geostationary, synchronous satellite by scanning the beam of a narrow beam width antenna in first and second orthogonal directions over a region including the source. The peak level of energy transduced by the antenna in each of the scanning directions is detected and correlated with the scanning position of the beam by feeding the output of a detector responsive to the transduced signal to an indicator of an X-Y recorder. The X and Y axes of the recorder are scanned in synchronism with the beam being respectively scanned in the first and second directions to form X and Y traces on which are indicated the detected peak position in each of the scanning directions. The source position is determined from an intersection of lines drawn parallel to the X and Y axes and including the detected peak position of each trace.

Abstract: A voltage regulated DC to DC converter is disclosed which is operable over a wide range of input voltage including voltages greater or less than the desired output voltage. The converter uses an inductor and a capacitor as storage elements, the inductor being composed of two windings having a common junction. A transformer having a center tap connected to the common junction of the two windings of the inductor is connected at either end of its winding to ground through controlled switches. One winding of the inductor and either end of the transformer winding are connected by respective power diodes to the capacitor which supplies the output voltage to a load. The other winding of the inductor is connected to a fourth power diode as a clamping diode. Input voltage is supplied to the inductor through a third controlled switch.

Abstract: A system for displaying at a remote station data generated at a central station and for powering the remote station from the central station. A power signal is generated at the central station and time multiplexed with the data and then transmitted to the remote station. An energy storage device at the remote station is responsive to the transmitted power signal to provide energizing power for the circuits at the remote station during the time interval data is being transmitted to the remote station. Typically, the data is time of day information and the remote station effects remote display of the time.Energizing power for the circuits at the remote station is provided by the power signal itself during the time this signal is transmitted. Preferably the energy storage device is a capacitor which is charged by the power signal during the time the power is transmitted and is slightly discharged during the time the data is transmitted to energize the circuits at the remote station.

Abstract: An antenna array comprising at least three interferometer pairs of antenna elements with selected spacings made to form a single beam which is readily scannable. All spatial frequencies generated by a signal and intercepted by the array are derived from a signal processing technique applied to the array. The array samples space in the spatial frequency domain while the signal processing technique utilizes real time convolution of functions in the spectral frequency domain. Summation of the appropriate spatial frequencies is equivalent to a Fourier transform operation, yielding the location of the signal source in space. Resolution and freedom from interference of the interferometer system is equal to that of a fully filled array of the same aperture size containing element spacings of one-half wavelength.