Abstract: A miniature accelerometer is fabricated using integrated circuit manufacturing and silicon micromachining techniques to form a closed loop, force balance sensor utilizing a silicon proofmass formed from and connected to a layer of silicon by a split flexure etched therein. The sensor circuitry detects AC signals coupled from the proofmass to a pair of electrodes formed on glass surfaces anodically bonded to the silicon layer. A DC restorative force is applied to the electrodes in response to the detected AC signals to balance acceleration forces applied to the proofmass. The sensor design is highly symmetrical.

Abstract: A star tracker for generating positional information for a vehicle includes a holographic telescope (150) having one or more fields of view for imaging stellar objects. The telescope includes a plurality of radiation detectors (100) and an input aperture comprised of a primary holographic optical element (HOE) (134). The primary HOE provides one or more wavefronts to one or more secondary HOEs (136), each of which applies a chromatic correction so as to correct for a chromatic aberration induced by the primary HOE. A single or multiple field of view Schmidt telescope embodiment is also disclosed having one or more aspheric corrector plate HOEs and one or more associated concave spherical reflectors.

Abstract: In a process for forming composite laminate parts from reinforcing fibers and resin, a mold is selected which has a mold cavity having a part definition surface therein and a resin passageway leading to the cavity. An expansion member capable of expanding to a larger volume in response to heat is located in the cavity in conjunction reinforcing fibers which will form a part of the composite laminate part. The mold cavity is closed and resin is injected through the resin passageway to saturate the fibers. The expansion member is heated to expand the expansion member an amount sufficient to consolidate the resin and the reinforcing fibers between the expansion member and the part definition surface to shape the fibers and the resin into a component laminate part mimicking the shape of the part definition surface and to expel any excess resin from the cavity to the passageway.

Abstract: A retro-reflective target tape comprising a lower sub-laminate having an upper transparent thick mylar backing about 2 mils thick, a release sheet therebeneath and a pressure sensitive adhesive therebetween; and an upper sub-laminate having an upper light reflective sheet with a thin, transparent mylar backing about a half mil thick therebeneath and with a pressure sensitive adhesive therebetween and with pressure sensitive adhesive beneath the thin mylar backing, the upper sub-laminate being cut to form a plurality of circular reflective targets and removed from the lower sub-laminate except for the plurality of circular reflective targets, the pressure sensitive adhesive above the release sheet remaining with the thick mylar backing upon the removal of the adjacent release sheet. Also disclosed is a method of fabricating such tape.

Abstract: Methods are disclosed for making semiconductor windows which are transparent to light in the infrared range which have good electrical conductivity and are formed of a substrate material (11) having a semiconductor coating (14) having a dopant included therein. The coating is diffused, grown or deposited on one surface of the substrate and is controlled to obtain both low electrical resistivity and high infrared transmissivity. The coating can be formed of the same material as the substrate or can be a different material. Windows having particular thermal properties are formed utilizing zinc selenide and zinc sulfide as the substrate.

Abstract: Monolithic InSb array devices are described for staring infrared imaging systems operating in the 3-5 .mu.m spectral region. These devices are fabricated with only 4 mask levels compared to 5 mask levels for prior devices and have higher output dynamic ranges and greater wafer yield compared to previous designs. The devices are fabricated to include a substrate (15) having a field oxide (16) pattern thereon. A first gate oxide (17) is deposited over the field oxide with columns (21) patterned on the first gate oxide. A second gate oxide (19) is next deposited with rows (22) patterned on the second gate oxide. The devices can further include a passivation layer (29) deposited on the rows (22).

Abstract: A spatial light modulator including a silicon backplate having an insulating layer and a standoff grid of insulating material deposited on the backplate to define an array of cells. An electrode is deposited in each cell on said backplate. A thin membrane of doped silicon is mounted to the standoff grid and over said array of cells and electrodes. Mirrors are laid on the membrane to create an array of reflective pixels over the array of cells. When an electrode is selectively charged the portion of the membrane overlying that cell is deflected by electrostatic attraction between the membrane and the electrode. Taken overall, a pattern is assumed by the array of pixels which corresponds to the state of the electrical signals placed on the electrodes.

Abstract: An adhesive patch for a composite structure, an adhesive for that patch and a method for forming the adhesive patch for the composite structure are described. The adhesive includes three uncured components of a bismaleimide polymeric mixture. Two of these components are liquid. The liquids include a liquid vinyl-terminated rubber monomer and a liquid bis(alkenylaromatic)aryl or bis(alkenylaromatic)alkyl monomer. The further component is a solid bismaleimide monomer that is intimately mixed and suspended in the liquid bis(alkenylaromatic)aryl or bis(alkenylaromatic)alkyl monomer and liquid vinyl-terminated rubber.

Abstract: A dielectric interference film having a central region of one thickness and a peripheral region of a different thickness is superimposed on one of the mirrors of a ring laser gyroscope for the purpose of suppressing off-axis resonant modes that are characteristic of a resonant cavity. The central region is designed to intercept a large portion of the fundamental mode power and a lesser portion of the off-axis mode power. The difference in thickness between the central and peripheral regions causes the reflected light from the two regions to differ in phase by approximately one-half wavelength and destructively interfere. As a result of the imbalance of the fundamental and off-axis mode powers incident on the central region, the reflectivity losses of the off-axis modes are more pronounced than those of the fundamental mode with the result that the off-axis modes are completely suppressed.

Abstract: High performance sailing yacht designs are disclosed based on a keelless sailing yacht concept having fore and aft cambered foils for leeway control which foils replace the function of the standard keel. A keelless sailing yacht of this type is disclosed with dynamic ballast which is laterally movable to apply a variable counter-heeling force; a tiltable mast which may have a rotatable mast and sail leading edge; cambered foils for cyclic and collective steering; and adjustable camber controls for adjusting lift and leeway. The foregoing features allow disclosed improvements and modifications to hull design in having a duplex hull form, with lower and upper hull shapes, the lower of low drag shape, and of reduced section, while the upper hull extends laterally abeam from the lower hull for added buoyancy when heeled and for accommodation room.

Abstract: A method of toughening a fiber/matrix ceramic composite consisting of non-oxide based ceramic fibers immersed in a ceramic matrix. The method includes, prior to immersing the fibers in the matrix, applying a metallo-organic solution of a noble metal to the fibers to form a coating of the solution on the fibers, evaporating the solvent from the solution and oxidizing the residual organic compounds whereby the coating becomes a pure noble metal and immersing the coated fibers in the matrix. The applying, evaporating, oxidizing and immersing steps are characterized by a limited raising of the temperature of the fibers. The coating is ductile so as to blunt advancing cracks in the matrix.

Abstract: An outboard control surface for an aircraft. The control surface is operably connected to wing side edges of the aircraft and includes a forward flap and a rearward flap with at least one of the flaps being movable into and out of alignment with the plane of the wing.

Abstract: A acousto-optic Fabry-Perot optical modulator (10) has a crystalline body (12) having a first partially reflective electrode (14) for receiving radiation, including laser radiation having a wavelength or wavelengths of interest, and a second, oppositely disposed partially reflective electrode (14) for emitting the received radiation including the laser radiation. The modulator is driven by an alternating source (16) at a resonant frequency of the crystalline body and intensity modulates at the resonant frequency only the emitted laser radiation. A detector (18) is positioned for receiving the emitted radiation, including the intensity modulated laser radiation, and has an output signal expressive of the intensity of the emitted radiation. Signal processing circuitry (20,34) is coupled to the detector output signal and is responsive thereto for identifying the intensity modulated laser radiation for indicating when laser radiation is received by the modulator.

Abstract: In a process for making a bonded article having a rigid foam core and a cured fiber-impregnated resin composite skin external of the foam core, a skin of a curable fiber-impregnated resin composite material is overlayed onto a shaped rigid foam core formed of a resin material that below is thermoelastic point is inflexible to expansion by internal gas expansion and below it thermoelastic point has a positive coefficient of thermal expansion. The composite material is chosen to have a cure temperature that is below the thermoelastic temperature of the foam core material. The foam core having the skin thereon is loaded into the cavity of a mold. The mold is closed, secured and heated to the cure temperature of the fiber-impregnated resin composite material to cure the fiber-impregnated resin composite material and to thermally expand the foam core via its positive coefficient of thermal expansion.

Abstract: A system and method for removing particulate matter from an object being machined or having been machined. A vacuum tube is connected to a source of vacuum and has an intake end adapted to be placed in close proximity to the object being machined. In one embodiment the intake end has a slot such that the intake end can at least partially surround a machining tool. In another embodiment the intake end has standoff buttons that are placed against the object. The vacuum tube can have an inlet cone with a bellmouth shape. Ionized gas is directed at the area proximate the inlet cone and/or machining tool. A vibrator can also be used to vibrate the object.

Abstract: A slant angle laser scanner for detecting underwater hazards, particularly those having a long axis along a radial from the ship such as torpedoes, using a laser, an electro-optical scanner and a rotatably mounted mirror to scan the ocean surface with optical beams at a low angle of incidence to form a circular pattern of radial scans surrounding the ship. The time of return of reflections can be measured to determine the depth of the hazard and the element illuminated within the liner array of photosensitive detectors indicates the location of the hazard along the radial scan. A boresight detector is used to detect the reflections and determine location and depth of the hazard.

Abstract: The disclosed invention employs a gravity assisted open system for coating of refractory substrates with a highly uniform layer of graphite or other material. Pyrolytic dissociation of precursor gases in an inert atmosphere flowing downwardly, countercurrent to the upward direction of transport of the substrate material, promotes condensation of the coating material on the moving substrate in a homogenous coating. The open configuration of the system allows continuous feed and takeup of substrate material to reduce startup and shutdown transient conditions affecting uniformity of the coating.

Abstract: Method and apparatus for switchably controlling the bias of a ring laser angular rate sensor using two switchably controllable magnetic mirrors for rate sensor operation away from lock-in regions. For a sensor input rate that is less than a threshold value, a control means switchably energizes each of the magnetic mirrors in a manner such that their respective optical effect is additive, one with the other, for biasing the rate sensor at a first desired operating point. For a sensor input rate that is at least equal to the threshold value, the control means switchably energizes each of the magnetic mirrors in a manner such that their respective optical effect is subtractive, one from the other, for biasing the rate sensor at a second desired operating point.

Abstract: Ultra strong lightweight core material capable of sustained operation at unusually high temperatures for composite structure of the type used in aircraft parts such as wings, fairings and stabilizers is produced from preimpregnated thermoplastic fibercloth ribbon by the manufacturing processes of this invention. The fibercloth ribbon is preformed between corrugated rollers of a special roll forming press which heats the ribbon to a softening temperature, forms it into a pattern of half-hex corrugations, cools it and sets it in that pattern. Then sheets cut from the corrugated ribbon are stacked into a bonding press along with hex forming mandrels placed between the sheets in the corrugations.