Abstract: A synthetic aperture radar correlation system including a moving diffuser located at the image plane of a radar processor. The output of the moving diffuser is supplied to a lens whose impulse response is at least as wide as that of the overall processing system. A significant reduction in clutter results.

Abstract: A symmetrical adsorption pump/compressor system having a pair of mirror image legs and a Joule Thomson expander 40, or valve, interposed between the legs thereof for providing a new, efficient refrigeration cycle. The system further includes a plurality of gas operational heat switches 48a, 48b, 48c, and 48d adapted selectively to transfer thereto heat from a thermal load 44 and to transfer or discharge heat therefrom through a heat projector 46, such as a radiator or the like. The heat switches comprise gas pressurizable chambers adapted for alternate pressurization in response to adsorption and desorption of a pressurizing gas confined therein.

Abstract: An apparatus is described which provides a numerical indication of the cloudiness at a particular time of a day. The apparatus includes a frame (18) holding several light sensors such as photovoltaic cells, with a direct sensor (12) mounted to directly face the sun and indirect sensors (13-16) mounted to face different portions of the sky not containing the sun. A light shield (30) shields the direct sensor from most of the sky except a small portion containing the sun, and also shields each of the indirect sensors from direct sunlight. The relative values of the outputs from the direct and indirect sensors, enables the generation of a numerical indication (56) of the degree of cloudiness at a particular time of day.

Abstract: A single-frequency multibeam synthetic aperture radar for large swath imaging is disclosed. Each beam illuminates a separate "footprint" (i.e., range and azimuth interval). The distinct azimuth intervals for the separate beams produce a distinct Doppler frequency spectrum for each beam. After range correlation of raw data, an optical processor develops image data for the different beams by spatially separating the beams to place each beam of different Doppler frequency spectrum in a different location in the frequency plane as well as the imaging plane of the optical processor. Selection of a beam for imaging may be made in the frequency plane by adjusting the position of an aperture, or in the image plane by adjusting the position of a slit. The raw data may also be processed in digital form in an analogous manner.

Abstract: A method and apparatus are provided for indicating the altitude of the tropopause or of an inversion layer wherein clear air turbulence (CAT) may occur, and the likely severity of any such CAT, which includes directing a passive microwave radiometer on the aircraft at different angles with respect to the horizon. The microwave radiation measured at a frequency of about 55 GHz represents the temperature of the air at an "average" range of about 3 kilometers, so that the sine of the angle of the radiometer times 3 kilometers equals the approximate altitude of the air whose temperature is measured. A plot of altitude (with respect to the aircraft) versus temperature of the air at that altitude, can indicate when an inversion layer is present and can indicate the altitude of the tropopause or of such an inversion layer. The plot can also indicate the severity of any CAT in an inversion layer.

Abstract: A method and apparatus for measuring Faraday rotation of a received rf signal. The disclosure describes a specific implementation of a simultaneous orthogonal polarization receiver which compensates for a 3 db loss due to splitting of a received signal into left circular and right circular polarization channels. The compensation is achieved by rf and modulation arraying utilizing a specific receiver array which also detects and measures Faraday rotation in the presence or absence of spin stabilization effects on a linear polarization vector. Either up-link or down-link measurement of Faraday rotation is possible utilizing the method and apparatus disclosed herein.

Abstract: A spaceborne synthetic aperture radar having pipeline multiple-look data processing makes use of excessive azimuth bandwidth in radar echo signals to produce multiple-look images. Time multiplexed single-look image lines from an azimuth correlator go through an energy analyzer which analyzes the mean energy in each separate look to determine the radar antenna electric boresight for use in generating the correct reference functions for the production of high quality SAR images. The multiplexed single look image lines also go through a registration delay to produce multiple-look images.

Abstract: A structure particularly suited for use in aerospace industries comprising a base plate, a cover plate, and an orthogonally corrugated core including a pair of core plates formed of a superplastic alloy interposed between the base plate and the cover plate, in sandwiched relation therewith and bonded thereto, each of the core plates being characterized by a plurality of protrusions comprising square-based, truncated pyramids uniformly aligned along orthogonally related axes perpendicularly bisecting the legs of the bases of the pyramids and alternately inverted along orthogonally related planes diagonally bisecting the pyramids, whereby an orthogonally corrugated core is provided.

Abstract: A solar-powered fluidized bed gasification system for gasifying carbonaceous material. The system includes a solar gasifier (10) which is heated by fluidizing gas and steam. Energy to heat the gas and steam is supplied by a high heat capacity refractory honeycomb (16) which surrounds the fluid bed reactor zone (14). The high heat capacity refractory honeycomb (16) is heated by solar energy focused on the honeycomb (16) by solar concentrator (32) through solar window (20). The fluid bed reaction zone (14) is also heated directly and uniformly by thermal contact of the high heat capacity ceramic honeycomb (16) with the walls of the fluidized bed reactor (12).Provisions are also made for recovering and recycling catalysts used in the gasification process. Back-up furnace (50) is provided for start-up procedures and for supplying heat to the fluid bed reaction zone (14) when adequate supplies of solar energy are not available.

Abstract: A fluidized bed coal reactor includes a combination nozzle-injector ash-removal unit formed by a grid of closely spaced open channels, each containing a worm screw conveyor, which function as continuous ash removal troughs. A pressurized air-coal mixture is introduced below the unit and is injected through the elongated nozzles formed by the spaces between the channels. The ash build-up in the troughs protects the worm screw conveyors as does the cooling action of the injected mixture. The ash layer and the pressure from the injectors support a fluidized flame holder combustion zone above the grid which heats water in boiler tubes disposed within and/or above the combustion zone and/or within the walls of the reactor.

Abstract: A method and apparatus is disclosed for use of a linear frequency chirp in a transmitter/receiver (14/16) having a correlator to synthesize a narrow beamwidth pattern from otherwise broadbeam transducers when there is relative velocity between the transmitter/receiver (14/16) and the target. The chirp is so produced in a generator (20) in bandwidth, B, and time, T, as to produce a time-bandwidth product, TB, that is increased for a narrower angle. A replica of the chirp produced in a generator (26) is time delayed and Doppler shifted for use as a reference in receiver (16) for correlation of received chirps from targets. This reference is Doppler shifted to select targets preferentially, thereby to not only synthesize a narrow beam but also aim the beam in azimuth and elevation.

Abstract: A display device particularly suited for providing the pilot of an aircraft with combined inflight attitude, heading, altitude, and horizontal situation information previously available only by using two or three devices providing separate displays. The preferred embodiment of this invention combines a commonly used and commercially available flight director-type device for providing a display in combination with a miniature aircraft supported for angular displacement from a vertical orientation to indicate heading error, or heading offset, and an extended course deviation indicator bar which projects into juxtaposition with the miniature aircraft for providing a true picture of the aircraft's horizontal situation relative to a selected VOR, ILS, or MLS course.

Abstract: A microwave limb sounder (MLS) to measure trace gases in the upper atmosphere by comparing spectral noise content of limb soundings with the spectral noise content of cold space utilizes an offset Cassegrain antenna system and a tiltable input mirror to alternately look out at the limb and up at cold space at an elevation angle of about 22.degree.. The mirror can also be tilted to look at a black body calibration target. Reflection from the mirror is directed into a radiometer the head of which functions as a diplexer to combine the input radiation and a local oscillator (klystron) beam. The radiometer head is comprised of a Fabry-Perot resonator consisting of two Fabry-Perot cavities spaced a number of half wavelengths apart. Incoming radiation received on one side is reflected and rotated 90.degree. in polarization by the resonator so that it will be reflected by an input grid into a mixer, while the klystron beam received on the other side is also reflected and rotated 90.degree.

Abstract: An optical gyroscope is described of the type which passes light beams in opposite directions through a single mode fiber optic wave guide that extends in a circle or coil, and which enables measurement of rotation rate of the coil by measuring the relative phase shifts of the beams by interferometric techniques, wherein simplification and enhanced accuracy are obtained. Beam splitting and phase shifting of the light is facilitated by utilizing brief pulses of light and by using light-controlling devices which are operated for a brief time only when the light pulse passes in one direction through the device but not at a different time when the pulse is passing in the opposite direction through the device. High accuracy in rotation measurement is achieved at both very slow and very fast rotation rates, by alternately operating the system so that at zero rotation the interfering waves are alternately 90.degree. out of phase and in phase.

Abstract: A head 10 for a high-speed spinner characterized by a substantially cylindrical body adapted to be mounted at the distal end of a vertically oriented drive shaft 16 and including a vacuum chuck having an upwardly facing chamber 30 circumscribed by an annular surface 32 for receiving in supported relation a silicon chip, and an ordered array of low-pressure cavities defined about the periphery of the body and connected in communication with the chamber via radially extended bores 38 for translating low pressures to the chamber 30 as the head is angularly displaced, whereby a pressure differential is established across the chip for securing it to the head.

Abstract: Hollow spheres with precisely concentric inner and outer spherical surfaces are formed by applying vibrations to a nonconcentric hollow sphere while it is at an elevated temperature at which it is fluid or plastic, the vibrations producing internal flows which cause the inner and outer surfaces to become precisely concentric. Concentric spheres can be mass produced by extruding a material such as glass or metal while injecting a stream of gas into the center of the extrusion to form a gas-filled tube. Vibrations are applied to the extruded tube to help break it up into individual bodies of a desired uniform size, the bodies tending to form spherical inner and outer surfaces by reason of surface tension, and the continuing application of vibrations causing these surfaces to become concentric.

Abstract: A high resolution interferometer is provided which is insensitive to slight misalignment of its elements, avoids channeling in the spectrum, generates a maximum equal path fringe contrast, produces an even two-sided interferogram without critical matching of the wedge angles of the beamsplitter and compensator wedges, and is optically phase tunable. The interferometer includes a mirror along the path of each beam component produced by the beamsplitter, for reflecting the beam component from the beamsplitter to a corresponding retroreflector and for reflecting the beam returned by the retroreflector back to the beamsplitter. The fact that the mirror "covers" the retroreflector, so that the mirror reflects the beam component before and after it reaches the retroreflector, results in the system being insensitive to slight tilting of the mirror.

Abstract: In a delay-lock one-delta (.+-.1/2 chip) dithered PN code tracking loop, an indication of lock in the PN code tracking loop is provided by delaying the dithered local PN code by a half chip to produce a +0, -1 dithered PN code that is then multiplied with the received PN-spread IF signal to produce a signal proportional to the correlation of this dithered code offset from the received code. The correlation signal is bandpass filtered, amplified with AGC control, and square-law detected to obtain a DC signal proportional to the degree of correlation. The DC signal is multiplied by the dithering control signal to effectively subtract noise voltage from the lock correlation signal which is then compared with a PN lock status signal.

Abstract: A method and apparatus for combining baseband signals from a large aperture antenna array in which none of the individual baseband signals has a sufficiently high signal-to-noise ratio to be used as a correlation or reference signal for phase adjusting the remaining baseband signals. More specifically, the invention provides a means whereby the baseband output signals of all but one of the receivers associated with each of the antennas are summed and used as a correlation reference for the baseband signal not contained in the summed signal, thereby providing a plurality of correlation or alignment loops, each having an output signal related to the phase difference between its input baseband signal and the summed signal. The invention further provides a means for subtracting an output or error signal generated in one of the correlation loops whose baseband signal has a predetermined phase delay from all the other alignment loops, thereby avoiding interaction and reflection effects in the signal combiner.

Abstract: A Schottky barrier solar cell consists of a thin substrate of low cost material with at least the top surface of the substrate being electrically conductive. A thin layer of heavily doped n-type polycrystalline germanium, with crystalline sizes in the submicron range, is deposited on the substrate. But first a passivation layer may be deposited on the substrate to prevent migration of impurities into the polycrystalline germanium on a substrate of low-cost conductive material. Then the polycrystalline germanium is recrystallized to increase the crystal sizes in the germanium layer to not less than 5 microns, and preferably considerably more. It serves as a base layer on which a thin layer of gallium arsenide is vapor-epitaxially grown to a selected thickness. Then, a thermally-grown oxide layer of a thickness of several tens of angstroms is formed on the gallium arsenide layer.