Abstract: A method for navigating an aircraft around the earth's polar region comprises the steps of determining if the aircraft is in one of the polar regions of the earth's traditional axis system. If the aircraft is not in one of the polar regions, aircraft parameters, including speed and heading, are calculated relative to the traditional axis system. If the aircraft is in one of the polar regions the traditional axis system is rotated to form a new axis system, such that the aircraft position in the new axis system is in an essentially rectilinear area of the new axis system. The aircraft parameters are transformed, including aircraft position, speed, and heading, into parameters relative to the new axis system. New parameters are calculated with respect to the new axis system, and then the new parameters are translated into parameters with respect to the earth's traditional axis system.

Abstract: A multigap liquid crystal color display having RED, GREEN and BLUE pixels with TFT activating transistors and with the pixels being constructed and arranged so that the offset voltages at the RED, GREEN and BLUE pixels induced by the gate pulses applied to the TFTs are equalized. In one embodiment, the pixel storage capacitors are customized to equalize the offset voltages. In a second embodiment, the pixel areas are adjusted so as to provide the offset voltage equalization.

Abstract: An apparatus and method for transmitting information between dual redundant components comprises two information sources each of which is coupled to two transmitters, the outputs of which are coupled to four signal paths for transmission to two independent voters. Each of the voters compares predetermined pairs of the signals on the four signal paths and provides a preferred one of the signals to a corresponding receiver based on the results of the pair comparisons.

Abstract: A modulator for providing modulating voltages across the anode and cathode of a negatively pulsed magnetron includes a switch which, when activated, couples the modulating voltage source to the cathode terminal, a current regulator which maintains a constant current flow through the anode and cathode when the modulating voltage is applied, and a voltage control circuit that reduces an excessive time rate of voltage change across the switch caused by arcing across the anode-cathode gap. A filament power supply is provided which supplies filament current while isolating the modulating voltage at the cathode from high voltage sensitive components in the filament power supply.

Abstract: In an aircraft, there is included a Flight Management System (FMS), Autopilot and Autothrottle for controlling the aircraft. The apparatus has a plurality of outputs for definition of the real-time targets, controlled by the Autopilot and Autothrottle, to guide the vertical position of the aircraft to a desired vertical position along the desired vertical flightplan (or profile) according to a set of operational procedures. The FMS includes an apparatus that comprises an element which provides information denoting actual vertical position of the aircraft, and an element which generates information specifying the desired vertical position of the aircraft along the predetermined desired flightplan.

Abstract: A method of processing a plurality of tracks representative of one or more target aircraft in a vicinity of a surveillance aircraft, where each track is generated in response to target reply signals provided by the target aircraft in response to interrogation signals transmitted by the surveillance aircraft, includes eliminating a portion of the plurality of tracks which are duplicate tracks of the same target aircraft. The remaining tracks are maintained and updated in response to the target reply signals provided by the target aircraft. A threat level for each of the remaining tracks is determined and two or more of the remaining tracks which are possibly representative of a same target aircraft are merged resulting in a composite track. The composite track is output to a display device utilizing information from a particular remaining track of the composite track having the greatest threat level to the surveillance aircraft while continuing to maintain and update all the remaining tracks.

Abstract: A three axis attitude orientation system for a spacecraft in orbit which employs a single UV sensor. The single sensor provides roll and pitch information by locating the centroid of the earth and using this as a reference point. The system determines yaw by tracking the position of stars which appear in the field of view around the earth. three axis attitude is determined through ultraviolet imaging of the earth's limb and adjacent stars. A non-conventional wide angle optics assembly and intensified CCD array are utilized for this purpose.

Abstract: A half-tone liquid crystal display panel having half-tone pixels, each comprising a plurality of sub-pixels including first and second sub-pixels. Activation voltage is supplied to the first sub-pixel from a TFT switch and to the second sub-pixel from the TFT switch through a coupling capacitor. The second sub-pixel includes a storage capacitor. Sensitivity of the activation voltage applied to the second sub-pixel resulting from capacitance non-uniformity across the panel is reduced by forming the coupling capacitor and the storage capacitor of the second sub-pixel with the same depositions utilizing a common dielectric layer. The capacitance of the storage capacitor of the second sub-pixel is designed large compared to the capacitance of the second sub-pixel.

Abstract: A multi-layered printed wiring board for high frequency application includes a first board of polytetrafluoroethylene (PTFE) having a metallic sheet on each side. The first side is etched to form high frequency circuity using micro-strip technology and the second side being a metallic sheet forming the ground plane. Laminated to the ground plane of the first board is a fiberglass board of thickness, A. Further, laminated to the fiberglass board is a second board of fiberglass having a thickness, A. The second board also has metallic sheets on both side, the side being laminated to the fiberglass board being etched to form strips, prior to being laminated, forming signal and transmission lines utilizing strip-line technology. Vias are formed to interconnect predetermined metallic layers.

Abstract: A display comprises a plurality of adjacent pixels wherein each pixel comprises three subpixels arranged in a triangular pattern, each having a hexagonal shape and substantially contiguous adjacent boundaries. This pattern allows predetermined subpixels to be increased or decreased in relative size without drastically affecting subpixel shape or the contiguous adjacent boundaries.

Abstract: A system for isolating a supported structure from transmitting vibrations to a supporting base in a spacecraft provides six degrees of freedom in a kinematic mounting. Six isolator elements in a symmetric arrangement of three skewed isolator pairs provides viscous damping and vibration and shock attenuation during launch and operation in space. The isolators employ two degrees of freedom flexure joints at each mounting point to assure primarily axial deflection and minimize bending moments, and have tuning springs to optimize performance. The system permits deterministic design and allows calculation of all loads from the nominal geometry and the isolator axial stiffness. Limit stops are provided between the supporting structure and the supported structure to limit excursions of the isolator members.

Abstract: A fault detection apparatus and method combines each of a plurality of redundant digital data signals with a unique key signal for transmission over one of a plurality of signal lines and recombines each with its unique key signal at a receiving end. The recombined signals are then compared at the receiving end to detect certain faults between or among the plurality of what should be identical received signals.

Abstract: A display apparatus including a light source, a liquid crystal panel, and one or more directional diffuser lens arrays disposed therebetween provides a tailored variation of luminance with viewing angle, a uniform variation of luminance with viewing angle within a first predetermined range of viewing angles and a concentration of light energy within a second predetermined range of viewing angles.

Abstract: A solder spacer device and method for use in positioning a grid pin array having a plurality of pins over a circuit board having a plurality of pin holes respectively receiving the pins. The spacer is pulled through a central opening in the circuit board after the pins are soldered in the holes to the circuit board. The spacer has a cylindrical body which is positioned in the central opening and has a plurality of radial legs having respective flexure portions for separating the pin grid array from the circuit board during soldering and for folding into the central opening during extraction through the central opening after the soldering is finished.

Abstract: A moving altitude tape for a flight instrument display adapted to provide intuitive visual cues for determining deviation from a desired altitude. A window incorporates a digital altitude readout and a pointer index which is aligned with calibration marks on the altitude tape. In use the tape exhibits a motion in accordance with deviations in altitude of the aircraft and displays a vernier indication of such deviations with respect to the reference index. The tape further includes indicia associated with the reference index for defining predetermined increments of altitude deviation in accordance with commonly commanded altitudes, and a further pointer indicative of actual altitude deviation from a preset altitude.

Abstract: An estimator for determining the distance of a moving vehicle to a stationary position includes the determination of actual and estimated velocities of the vehicle along a selected path. An up-dated distance estimate is established by multiplying estimated distance by the ratio of the actual velocity to the estimated velocity. The up-dated estimate is then utilized as the estimated and another up-dated distance is obtained. Iterations continue until the ratio approaches unity indicating that the estimated distance is approximately equal to the actual distance.

Abstract: A step attenuator comprises two branchline couplers with two coupling transmission lines therebetween. Attenuation is accomplished through switchable resistors, in series with switching diodes, shunted across the transmission lines. These resistors reflect and absorb incident power. Switching signals are provided to the diodes through the branchline couplers and the coupling transmission lines. The reflected power is absorbed by a matched termination at the port of the input branchline coupler that is isolated from the port at which the signal to be attenuated is coupled. Phase shift and insertion loss are minimized by tuning the series inductance inherent in the diode resistor combination with tuning capacitors in series therewith. These capacitors are by passed by low-susceptance inductors which provide a dc path to ground for the diodes.

Abstract: A viscous damper for absorbing vibrations of low amplitude over a wide frequency range. Two working volumes of resiliently deformable material, in the form of a bellows, are provided in a folded structure joined by a base carrying a restrictive annular fluid passage. Compressive forces applied to the primary volume are transmitted by a damping fluid through the restrictive annulus to the secondary volume, the resulting energy dissipation providing a damping effect. A hermetically sealed configuration provides multi-axis damping and isolation without wearing of frictional surfaces. Large damping values are attained with linear performance over a large dynamic range.

Abstract: During ATCRBS surveillance procedures, a multiplicity of target aircraft are typically detected through target replies from interrogation signals. However, the nature of the target acquisition procedures are such that positive identification of the target aircraft is not available. Rather than ordering the target tracks with increasing range and correlating the target replies with tracks based on the ordering of the target tracks, the tracks are prioritized, based on confidence in the reliability of the identification of each track, into groups. An attempt to correlate the tracks of each group with the set of target replies is performed for the groups in order of decreasing priority. A target reply is assigned to a track when a correlation between a track and a target reply is determined.

Abstract: An improved distributed processing system for controlling the transfer of data between a terminal controller and a subsystem is described where the improvement insures wordstring consistency in a manner which is completely transparent to the subscriber subsystem. In particular, data is transferred, via a dual-bank, dual-port terminal memory where the bank selection is controlled such that any wordstring transfers between the terminal memory and the terminal controller are constrained to involve a different bank than transfers between the terminal memory and its associated subscriber subsystem. A wordstring log associated with control arbitration logic contains the dynamic state of the bank assignments for each wordstring. Two flag bits in the wordstring log provide information to the control/arbitration logic, allowing it to manage the bank selection of the terminal memory.