Abstract: A flat panel display for presenting graphical renderings of aircraft flight, operation and system status data to an aircraft pilot renders the data at various predetermined brightness levels depending on the category of data assigned to that data. Primary data appears on the screen at a full brightness level and secondary data appears on the screen at a brightness level less than the full brightness level. In this manner, a wide variety and range of aircraft flight, operation and system status data can be simultaneously conveyed to the pilot on a single display screen through selective illumination of particular classes or categories of the data on the display at predetermined brightness levels, thereby advantageously directing the pilot's attention specifically to the primary data which is presented at full brightness.

Abstract: A system and method for facilitating user entry of a manually-adjustable data setting in an aircraft cockpit normally presents an image of the data setting on the display at a predetermined size. When the user commences to manipulate a control for manually adjusting the data setting, the imaged data setting on the display is automatically enlarged to a predeterminately enlarged size to thereby unambiguously direct the user's attention to the imaged data setting to be adjusted. The imaged data setting on the display is returned from its enlarged size to its normal size when user manipulation of the control has ceased, preferably a predetermined time interval after such user manipulation has ceased.

Abstract: A backlit flat panel display includes a fluorescent tube positioned for illuminating the display, and a plurality of display illuminating LEDs on the periphery of the display. The fluorescent tube illuminates the display through a first range of brightness above a predetermined transition level and the LEDs illuminate the display through a second range of brightness below the transition level. When the illumination of the display is adjusted through the transition level to account for changes in ambient light, the LEDs and the fluorescent tube are operated together, so that the combined brightness of the illumination provided by the LEDs and the fluorescent tube will provide the desired display brightness; this advantageously compensates for delayed illumination of the fluorescent tube at start up and for persistence in the tube after shutdown.

Abstract: A flat panel display system for an aircraft display includes a graphics rendering computer for rendering of anti-aliased graphical imaging data derived from aircraft sensors for full-field imaging on a cockpit display screen. A comparator processor independently generates, from the same sensor data, a selected subset or “points of light” of the display screen image and compares the points of light data to the data generated by the rendering computer for the same display screen pixel locations. The minimized processing requirements and simplified design of the comparator processor enable ready FAA certification of the comparator processor, whereas the extreme complexity and processing operations required of the rendering computer make FAA certification thereof unusually time consuming and expensive.

Abstract: An image display generator for use in a head-up display includes an array of light emitting devices such as LEDs or VCSELs formed on a semiconductor layer deposited on one surface of a glass like, e.g. Sapphire, sheet in which a plurality of lenses are formed on the opposite surface with each lens aligned with a respective one of the LEDs or VCSELs. A layer of transparent insulating material is disposed over the semiconductor layer and is coated with a reflecting material. Light emitted by the LEDs is directly incident onto respective over the lenses and is indirectly reflected onto the lenses by the reflecting material.

Abstract: In an aircraft conventionally-including a redundant pair of independent primary altitude determination systems of accuracy certified for RVSM operations, an initially loosely calibrated backup altimeter receives independent static pressure data for use in calculating altitude. During normal flight of the aircraft, the current altitude determinations of the primary altimeters and, using a recursive filter, the static source error correction (SSEC) of the backup altimeter is recursively adjusted until the SSEC attains a steady-state value with which the calculated altitude determinations by the backup altimeter accurately conform to the altitude determinations of the primary altimeters. Through this self-correction functionality the backup altimeter is rendered sufficiently accurate for permitted use in RVSM airspace in the event of a failure of one of the primary altitude determination systems.

Abstract: An improved flat panel display provides reduced reflection of incident light on the display to improve display visibility. The display includes a transparent top cover panel such as glass which is bonded or laminated to the display polarizer. The outer viewing surface of the top cover panel carries a plurality of integral surface features defined in the surface, which may comprise etched bumps or micro-machined tetrahedron-shaped protuberances that may be truncated, smoothed, and/or variously oriented and sized to further reduce incident light reflectivity. A multi-layer HEA coating on the featured surface defines a graduated transition layer with an index of refraction that gradually, and preferably smoothly, varies from layer to layer of the HEA coating from the index of refraction of the top cover panel to the index of refraction of the ambient air or other material which the outermost viewable surface of the display presents an image to an observer or viewer.

Abstract: An altimeter which contains within it means for storing the Static Source Error Correction (SSEC) for the aircraft. The altimeter includes means for downloading the SSEC and for transferring it to a new altimeter which may then be used in place of the original altimeter without losing the information built up over time or having to re-calibrate the new altimeter based on new tests. The altimeter also includes means for uploading a known SSEC thereto.

Abstract: A flat panel display system for an aircraft display includes a graphics rendering computer for rendering of anti-aliased graphical imaging data derived from aircraft sensors for full-field imaging on a cockpit display screen. A comparator processor independently generates, from the same sensor data, a selected subset or “points of light” of the display screen image and compares the points of light data to the data generated by the rendering computer for the same display screen pixel locations. The minimized processing requirements and simplified design of the comparator processor enable ready FAA certification of the comparator processor, whereas the extreme complexity and processing operations required of the rendering computer make FAA certification thereof unusually time consuming and expensive.

Abstract: An image display generator for use in a head-up display includes an array of light emitting devices such as LEDs or VCSELs formed on a semiconductor layer deposited on one surface of a glass like, e.g. Sapphire, sheet in which a plurality of lenses are formed on the opposite surface with each lens aligned with a respective one of the LEDs or VCSELs. A layer of transparent insulating material is disposed over the semiconductor layer and is coated with a reflecting material. Light emitted by the LEDs is directly incident onto respective over the lenses and is indirectly reflected onto the lenses by the reflecting material.

Abstract: A system and method for providing highly accurate measurements of the altitude above ground level (AGL) of an aircraft flying over local terrain. A current AGL altitude of the aircraft over local terrain is obtained by activating a radar altimeter on the aircraft for a single short duration or pulse. A mean sea level (MSL) elevation of the local terrain is determined by identifying the terrain from the then-current aircraft geographical position coordinates and utilizing known terrain topography data. The actual MSL altitude of the aircraft can then be determined. An uncorrected MSL altitude of the aircraft is then determined from conventional static air pressure measurements and the difference between the actual MSL altitude and the uncorrected MSL altitude of the aircraft yields a local barometric correction factor for use in determining MSL altitude measurements of the aircraft as the aircraft flies over and continues its flight away from the local terrain.

Abstract: A system and method for providing highly accurate measurements of the altitude above ground level (AGL) of an aircraft flying over local terrain. A current AGL altitude of the aircraft over local terrain is obtained by activating a radar altimeter on the aircraft for a single short duration or pulse. A mean sea level (MSL) elevation of the local terrain is determined by identifying the terrain from the then-current aircraft geographical position coordinates and utilizing known terrain topography data. The actual MSL altitude of the aircraft can then be determined. An uncorrected MSL altitude of the aircraft is then determined from conventional static air pressure measurements and the difference between the actual MSL altitude and the uncorrected MSL altitude of the aircraft yields a local barometric correction factor for use in determining MSL altitude measurements of the aircraft as the aircraft flies over and continues its flight away from the local terrain.

Abstract: An air data measurement system includes a device for sensing air pressure outside an aircraft, a pressure transducer in fluid communication with the air pressure sensing device and having a piezoresistive bridge attached on a flexible diaphragm. The piezoresistive bridge has an electrical resistance which varies in response to the sensed air pressure applied to the diaphragm and whose sensitivity varies with the magnitude of the excitation current passing therethrough. The system also includes a current supply operatively connected to the pressure transducer for supplying and varying the magnitude of the excitation current to the piezoresistive bridge. Further included is an output device connected to the pressure transducer for sensing a change in the electrical resistance of the piezoresistive bridge and outputting a signal from the piezoresistive bridge corresponding to the sensed air pressure.

Abstract: A method for calibrating a pressure-sensing altitude sensor of an aircraft while the aircraft is in flight. The method includes the steps of obtaining a set of reference atmospheric pressures as a function of height above a base station by affixing a reference pressure sensor to a balloon. As the balloon is released into the atmosphere, the reference sensor continuously measures the atmospheric pressures and transmits the data back to the base station while a ground-based radar disposed adjacent the base station measures the height of the balloon. An aircraft flying in a vicinity of the base station can calibrate its pressure-sensing altitude sensors by measuring the atmospheric pressure outside the aircraft and its geometric height relative to the base station and then comparing the pressure measurements with corresponding reference pressure values at a geometric height that is substantially that same as the geometric height of the aircraft.

Abstract: A time-varying control signal is developed by a current sensor connecting the imaging screen and a closely proximate screen grid of a cathode ray tube as an imaging electron beam is operatively swept across the screen to produce images thereon. The control signal is processed and then applied to at least one of the tube operating elements--such as the horizontal and vertical deflection coils, the focusing lens, the electron beam generator and, in a plural beam tube, the convergence assembly--which controls a characteristic affecting the quality of an image. Specific arrangements for using the time-varying control signal to compensate for geometric image distortions affecting horizontal linearity and to increase the imaging resolution of the tube are disclosed.

Abstract: A time-varying control signal is developed by a current sensor connecting the imaging screen and a closely proximate screen grid of a cathode ray tube as an imaging electron beam is operatively swept across the screen to produce images thereon. The control signal is processed and then applied to at least one of the tube operating elements--such as the horizontal and vertical deflection coils, the focusing lens, the electron beam generator and, in a plural beam tube, the convergence assembly--which controls a characteristic affecting the quality of an image. Specific arrangements for using the time-varying control signal to compensate for geometric image distortions affecting horizontal linearity and to increase the imaging resolution of the tube are disclosed.

Abstract: A fluid density measuring device or densitometer computes, electronically, the density of a fluid by measuring the resonant frequency of an excitation signal provided to a density transducer (11) immersed in the fluid. The frequency at which resonance occurs in the circuit (13, 15, 17, 21, 23, 25, 29, 31, 37, 41) will vary according to the density of the fluid, and this information is used by measuring electronics (31, 37, 41, 43), including a programmed microprocessor (43), to calculate the density of the fluid. The output of the microprocessor (43) may be a display of fluid density information or may be transmitted to a fuel gauge.

Abstract: An internal electrostatic field-generating, beam-controlling element in a cathode ray tube is formed by depositing an initially continous layer of resistive material on a substrate and applying a voltage differential across the coating to generate a field-generating current therethrough during operation of the tube. After completion of tube assembly and sealing of the tube envelope, the element is custom fine-tuned by projecting an externally-originating laser beam through the envelope wall to selectively remove portions or areas of the resistive material, thereby predeterminately distorting the electrostatic field and selectively changing the effect of the field on the imaging electron beam. This procedure readily enables both correction of perceived deficiencies in and intentional modifications to one or more characteristics of the electron beam.

Abstract: A pressure transducer cross-check system (10) in which a pair of low precision pressure transducers (12, 14) which detect parameters related to each other in content are alternately periodically calibrated during the operation of the system by cross-checking by a solenoid actuated valve (18) which alternately connects one of the pair of low precision pressure transducers (12, 14) to its associated pressure input (20, 22) while connecting a common high precision pressure transducer (16) to the other of the related pressure parameter inputs (20, 22) for selectively alternately providing one of the pair of parameter input signals as a high precision pressure responsive input signal to the system controller on alternate cycles of the low precision pressure transducer pair in accordance with the cycling of the valve (18).

Abstract: A mach airspeed indicator capable of internally determining mach number and VMO from measured altitude and airspeed information directly. An internal microprocessor, capable of storing a plurality of selectable VMO curves and a table of mach number versus q.sub.c /P.sub.s, receives the measured altitude and airspeed information, determines VMO and mach number therefrom, and directly drives the VMO and mach number displays where q.sub.c represents the impact pressure and P.sub.s represents the static pressure. The measured altitude and airspeed signals are analog synchro signals. In order to drive the VMO display, the received analog altitude synchro signals are digitized in a synchro-to-digital converter comprising a single multiplying digital-to-analog converter for both sin .theta. and cos .theta. synchro functions, and fed to the microprocessor which verifies the appropriate VMO from the preselected VMO curve, and drives the VMO analog pointer via a stepper motor servo loop closed by the microprocessor.