Showing papers by "Raytheon published in 1995"

Product Reliability, Maintainability, and Supportability Handbook

Abstract: PRODUCT EFFECTIVENESS AND WORTHProduct AttributesProgrammatic FactorsProduct Effectiveness FactorsOperational AvailabilityDesign, Use, and Logistic EffectivenessDesign Effectiveness.. Use Effectiveness. Logistic EffectivenessReliabilityMission Reliability. Logistic ReliabilityRestorationMaintainabilityTime Elements and Product EffectivenessRelationships among Time IntervalsAssigning ResponsibilityIntegrated Product and Process DevelopmentManaging Product EffectivenessSummaryPROBABILITY CONCEPTSRandom EventsDefinitions of ProbabilityBasic Theorems of ProbabilityConditional Probability and Multiplication Rule. Statistical Independence. Total Probability Theorem. Bayes' TheoremRandom Variables and Their DistributionsRandom VariablesProbability DistributionMain Descriptors of a Random VariableMean. Variance and Standard Deviation. Markov Inequality. Chebyshev Inequality. Skewness. Quantiles and PercentilesBrief Review of DistributionsDiscrete Distributions. Continuous DistributionsMultiple Random VariablesJoint Probability. Conditional Probability DistributionsCovariance and CorrelationFunctions of Random VariablesProbability DistributionsMain Descriptors of Random FunctionsRandom ProcessesDefinition of a Random ProcessMain Descriptors of Random ProcessMean Value. VarianceStationary Random ProcessesErgodicity of Random ProcessesCounting ProcessesRecurrent Point ProcessesMarkov ProcessSome Limit Results in Probability and Stochastic ProcessesLimit Theorems in Probability TheoryThe Central Limit Theorem. The Poisson Theorem. A Random Number of Random Variables in a SumStochastic ProcessesCrossing a "High Level" by Continuous Process. Thinning a Point ProcessThe Superposition of Point ProcessesSTATISTICAL INFERENCE CONCEPTSStatistical EstimationPoint EstimationMethod of Moments. Method of Maximum LikelihoodInterval EstimationHypothesis TestingFrequency HistogramGoodness-of-Fit TestsThe Chi-Square Test. The Kolmogorov-Smirnov Test. Sample ComparisonReliability Regression Model FittingGauss-Markov Theorem and Linear RegressionRegression Analysis. The Gauss-Markov Theorem. Multiple Linear RegressionProportional Hazard (PH) and Accelerated Life (AL) ModelsAccelerated Life (AL) Model. Proportional Hazard (PH) ModelAccelerated Life Regression for Constant StressAccelerated Life Regression for Time-Dependent StressPRACTICAL RELIABILITY CONCEPTSReliability MeasuresTime-to-Failure Distribution and Reliability FunctionMean Time to Failure and Percentile LifeFailure Rate and Cumulative Hazard FunctionLife Distributions as Reliability ModelsGeometric DistributionThe Binomial DistributionExponential DistributionClasses of Distribution Functions Based on AgingFailure Rate and the Notion of Aging. Bounds on Reliability for Aging Distributions. Inequality for Coefficient of Variation. Cumulative Damage ModelThe Weibu

Power conditioning system for a four quadrant photovoltaic array with an inverter for each array quadrant

Abstract: A photovoltaic (PV) power system having distributed square wave current DC to AC inverters integral with strings of PV cells in a PV array. The PV array is arranged into four quadrants and phase-shifted and summed AC voltages from each quadrant are further summed in a 12-phase to 3-phase transformer to produce a sinusoidal 3-phase AC voltage with a total harmonic distortion of less than 5 percent.

The Thermal Ion Dynamics Experiment and Plasma Source Instrument

Abstract: The Thermal Ion Dynamics Experiment (TIDE) and the Plasma Source Instrument (PSI) have been developed in response to the requirements of the ISTP Program for three-dimensional (3D) plasma composition measurements capable of tracking the circulation of low-energy (0-500 eV) plasma through the polar magnetosphere. This plasma is composed of penetrating magnetosheath and escaping ionospheric components. It is in part lost to the downstream solar wind and in part recirculated within the magnetosphere, participating in the formation of the diamagnetic hot plasma sheet and ring current plasma populations. Significant obstacles which have previously made this task impossible include the low density and energy of the outflowing ionospheric plasma plume and the positive spacecraft floating potentials which exclude the lowest-energy plasma from detection on ordinary spacecraft. Based on a unique combination of focusing electrostatic ion optics and time of flight detection and mass analysis, TIDE provides the sensitivity (seven apertures of about 1 cm squared effective area each) and angular resolution (6 x 18 degrees) required for this purpose. PSI produces a low energy plasma locally at the POLAR spacecraft that provides the ion current required to balance the photoelectron current, along with a low temperature electron population, regulating the spacecraft potential slightly positive relative to the space plasma. TIDE/PSI will: (a) measure the density and flow fields of the solar and terrestrial plasmas within the high polar cap and magnetospheric lobes; (b) quantify the extent to which ionospheric and solar ions are recirculated within the distant magnetotail neutral sheet or lost to the distant tail and solar wind; (c) investigate the mass-dependent degree energization of these plasmas by measuring their thermodynamic properties; (d) investigate the relative roles of ionosphere and solar wind as sources of plasma to the plasma sheet and ring current.

RF sensor and radar for automotive speed and collision avoidance applications

Abstract: Radar apparatus (10) that includes a millimeter wave radar transmitter (11) comprising a flood beam antenna (17), and a radar signal processor (30) for processing radar return signals to produce radar output signals. An RF sensor (20) comprising a receive antenna (21) includes a plurality of antenna elements (21a), a plurality of mixers (22) respectively coupled to outputs of the plurality of antenna elements (21a) and coupled to the transmitter (14) by means of a coupler (26), a plurality of filter circuits (23) respectively coupled to outputs of the plurality of mixers (22), a multiplexer (24) coupled to outputs of the plurality of filter circuits (23) that comprises as a multiple input, single output switch (25) for sequentially outputting video signals derived from radar signals received by each of the receive antenna elements (21a), and a lens (27) for imaging radar returns onto each of the plurality of antenna elements (21a). The heart of the present invention is a heterodyne receive antenna (21) that may be used in many applications, including radiometric or radar applications, and the like. The present invention provides for a 35-300 GHz millimeter wave electronic scanning sensor (20) for use in collision avoidance applications, and the like.

Method for manufacturing a coaxial interconnect

Abstract: A multi-chip-module comprising a plurality of vertically layered substrates and including a plurality of coaxial inter-connects formed between and through the substrate layers. Each of the coaxial inter-connects is formed by a process wherein: an outer hole (aperture) is drilled through the substrate and lined with an electrically conductive material to form an outer via; the outer via is filled with a dielectric material; and, an inner hole (aperture) is drilled through the dielectric material and filled with an electrically conductive material to form a center via. The characteristic impedance of the coaxial inter-connect is determined by the selection of the outer diameters of the drilled holes for the outer and center vias.

Deterministic network protocol

Abstract: A deterministic network protocol for connecting critical sensors, actuators and computing elements on a bi-directional, time-multiplexed, fiber optic or other media data bus, such that critical messages have concisely bounded latency and non-critical messages may be sent without impacting critical messages. It is a unique combination of a time-slot allocation protocol and a contention-based protocol in which global synchronization information is passed on the data media via a synchronization beacon.

Microstrip flexible printed wiring board interconnect line

Abstract: An RF flexible printed wiring board transmission line for connecting strip transmission line microwave assemblies without the use of coaxial connectors and coaxial cables. The flexible transmission line includes a thin flexible dielectric ribbon, having on one side a ground plane layer and on the other side a microstrip conductor strip. Plated through holes at the ends of the flexible line provide access to both the ground plane and conductor strip on the same side of the flexible line, to facilitate interconnection of the microwave assemblies to the flexible line. The flexible line operates at microwave frequencies with little or no radiation leakage.

Fiber optic switching system

Abstract: A data communication system comprising a plurality of fiber optic cables and a fiber optic switching system, comprising: a support structure for securing light emitting/light receiving ends of the plurality of fiber optic cables in predetermined positions; and, means for re-directing light emitted from the light emitting/light receiving end of one of the fiber optic cables to the light emitting/light receiving end to the light emitting/light receiving end of another one of the plurality of fiber optic cables. The re-directing means includes means for collimating and directing the light emitted from the end of one of the cables as a beam propagating along a predetermined direction and for re-directing the beam towards the end of another one of the cables selectively in accordance with an electrical signal. More particularly, the re-directing means includes electro-optical phase shifting medium, preferably liquid crystal molecules.

Infrared pyroelectric sensor for detection of vehicular traffic using digital signal processing techniques

Abstract: An experimental passive infrared system was designed and developed to detect and monitor vehicular road traffic. The system uses infrared pyroelectric sensors to sense vehicles passing through its field of view. In conjunction with computerized signal processing and correlation techniques the sensor information can then be used to count the number of vehicles passing and compute their speed and length. Laboratory and field tests results indicate that this technology should be cost effective, weather resistant and have the potential for a variety of sophisticated traffic monitoring applications. >

Laser scribing on glass using Nd:YAG laser

Abstract: This invention pertains to a method and apparatus for inscribing a pattern into a surface of a substrate, such as a sheet of glass. The method includes the steps of providing a Nd:YAG laser (12) having a characteristic output wavelength of 1.06 micrometers; providing a glass substrate (18) that is substantially transparent to the characteristic output wavelength; and applying a layer of material, such as a layer of tape (16), to a surface (18a) of the substrate. The layer of material is selected so as to strongly absorb the characteristic output wavelength. A next step focuses (14) an output of the laser into a spot (12c) at or near to an interface between the layer of material and the surface of the substrate. A further step translates (20) the surface relative to the spot. The layer of material absorbs the output of the laser and is heated thereby to a temperature sufficient for inscribing the surface underlying the spot. That is, the layer of material enables the laser to build a plasma state adjacent to the surface of the substrate, which in turn scribes the surface of the substrate.

Modular helmet-mounted display

Abstract: An aviator's helmet-mounted display includes a visor/combiner module (14) which is configured for use with an essentially standard aviator's flight helmet (12). The helmet-mounted display also includes a conformal image source and relay optics (ISRO) module (30) which is removably attachable to the aviator's helmet. This ISRO module (30) projects an image inwardly from outside the visor/combiner module through a transparent window portion (44) thereof and out and inner surface (48) of an angulated transparent viewing portion (18,20) of the visor/combiner module (14). The image is focused at infinity and is partially reflected from the inner surface (48) to an eye (50) of the aviator so that the image is superimposed on the aviator's view of an outside scene viewed through the viewing portion (18,20).

Compact antenna with folded substrate

Abstract: An antenna having: a beam forming network; an array of antenna elements; and a parallel plate region coupling the array of antenna elements and the beam forming network formed on a common, folded dielectric substrate. The beam forming network includes strip conductor circuitry separated from a ground plane conductor by a portion of the substrate. The array of antenna elements comprising strip conductor circuitry separate from a ground plane conductor by a second portion of the substrate. The parallel plate region is disposed about a folded region of the substrate and includes a pair of conductive plates separated by the folded region of the substrate. With such arrangement, a compact antenna is provided using the folded substrate. Also, spurious radiation (which has been found to radiate when strip conductor circuitry is disposed about the folded region to couple the array of antenna elements and the beam forming network) is confined by the parallel plate region.

A Reduced Order Model of Unsteady Flows in Turbomachinery

Abstract: A novel technique for computing unsteady flows about turbomachinery cascades is presented. Starting with a frequency domain CFD description of unsteady aerodynamic flows, we form a large, sparse, generalized, non-Hermitian eigenvalue problem that describes the natural modes and frequencies of fluid motion about the cascade. We compute the dominant left and right eigenmodes and corresponding eigenfrequencies using a Lanczos algorithm. Then, using just a few of the resulting eigenmodes, we construct a reduced order model of the unsteady flow field. With this model, one can rapidly and accurately predict the unsteady aerodynamic loads acting on the cascade over a wide range of reduced frequencies and arbitrary modes of vibration. Moreover, the eigenmode information provides insights into the physics of unsteady flows. Finally we note that the form of the reduced order model is well suited for use in active control of aeroelastic and aeroacoustic phenomena.

Scanned antenna system

Abstract: Compact, microwave scanned antennas include combinations of a radiator, a reflector and a mirror. The radiator is formed by plating a shaped dielectric core. It generates an antenna beam at an output aperture in response to a microwave signal at an input port. The wavefront orientation of the antenna beam is a function of the wavefront orientation of the microwave signal at the input port. Changing the angular relationship between the path of the microwave signal and the input port changes the wavefront orentation of the antenna beam and, therefore, its beam axis. Pivoting the reflector realizes the desired angular change in the microwave signal path. Alternatively, the reflector can be fixed and the mirror pivoted to vary the microwave signal path. Antenna embodiments can be physically realized with a single moving part, the shaped dielectric is easy to form and when configured to operate at a high frequency, e.g., 77 GHz, the antenna is small enough to fit behind an automobile license plate.

Optical rotary joint for single and multimode fibers

Abstract: The present invention provides a rotary joint for optical fibers comprising a plug assembly and a first ferrule having a fiber-entry end mounted coaxially therein, a receptacle assembly and a second ferrule having a fiber-entry end mounted coaxially therein, wherein at least one of the plug-mounted ferrule and the receptacle-mounted ferrule is biased outwardly from a fiber entry-end of the ferrule, and an alignment sleeve for optically connecting the first and second ferrules and maintaining the optical connection during rotation of one of the plug assembly and the receptacle assembly about an axis parallel to a longitudinal direction of the assembly relative to the other of the plug assembly and the receptacle assembly.

Staring IR-FPA with on-FPA adaptive dynamic range control electronics

Abstract: An adaptive dynamic range control circuit architecture is disclosed that enables an IR-FPA (10) to achieve a higher dynamic range. The circuit architecture significantly reduces a resolution required for an analog-to-digital converter (ADC 24) that converts the analog output signals of the IR-FPA to a digital representation. In a preferred embodiment of this invention a column CTIA readout integrated circuit architecture is used in conjunction with the adaptive feedback circuitry of this invention to provide pedestal suppression on a per-pixel basis for the IR-FPA. The use of the circuitry of this invention modifies the conventional column CTIA amplifier configuration to a configuration having an auto-zeroed charge ratioed gain stage (50). One advantage to this technique is that by suppressing the charge pedestal, the usable signal output from the IR-FPA can be brought off-chip to the readout integrated circuit at a much higher gain. As a result, the ADC requires fewer bits to resolve the useable signal information and dynamic range.

System and method for high resolution volume display using a planar array

Abstract: An image display apparatus comprises a main display and an auxiliary display. The main display is used to produce a volumetric image such as graphical image, and the auxiliary display is used to generate two dimensional image such as text image. The auxiliary display is located adjacent the the main display and being able to move relative to the main display along a path extending in a direction substantially circumferential to the main display.

Position and orientation estimation neural network system and method

Abstract: Disclosed are a system and method for determining the pose (translation, rotation, and scale), or position and orientation, of a model object that best matches a target object located in image data. Through an iterative process small adjustments are made to the original position and orientation of the model object until it converges to a state that best matches the target object contained in the image data. Edge data representative of edges of the target object and edge data representative of the model object are processed for each data point in the model object relative to each point in the target object to produce a set of minimum distance vectors between the model object and the target object. A neural network estimates translation, rotation, and scaling adjustments that are to be made to the model object. Pose of the model object is adjusted relative to the target object based upon the estimated translation, rotation, and scaling adjustments provided by the neural network. Iterative calculation of the minimum distance vectors, estimation of the translation, rotation, and scaling adjustments, and adjustment of the position and orientation of the model object is adapted to reposition the model object until it substantially overlays the target object. Final position of the model object provides an estimate of the position and orientation of the target object in the digitized image.

Data processor with dynamic and selectable interconnections between processor array, external memory and I/O ports

Abstract: A data processor intended for a single instruction, multiple data mode operation includes memory that is external to the processor array, and a controller that dynamically and selectably interconnects multiple edges of the processor array with the memory and with I/O ports. A separate controller module is provided for each memory channel, and interconnects with corresponding edge processing elements of the processor array. The controller modules for the different channels are independent of each other, as are the channel memories. In the case of a rectangular processor array, each channel memory can be implemented with only three memory stores that are interconnected with the four edges of the processing array and the I/O ports through the channel controller module, yet for most algorithms provide a throughput that is comparable to that resulting from the use of four memory stores.

Thermal management of VCSEL-based optoelectronic modules

Abstract: Thermal management is critical to reliable optoelectronic modules based on vertical-cavity surface-emitting lasers (VCSELs). One critical thermal path to be managed is from a VCSEL to a case (heat sink), which is affected by packaging technologies and materials The measured VCSEL-to-case resistance of a laser with 8-/spl mu/m aperture was 1650/spl deg/C/W, and that of a 20-/spl mu/m device was 1070/spl deg/C/W. These thermal resistances are much larger than those for the edge-emitting lasers; advanced device and packaging technologies are being developed to reduce these resistances. To study the packaging effects, a three-dimensional (3-D) numerical model has been developed and calibrated by the measured data. The calibrated model was used to understand the difference in thermal behavior: 1) between a wire-bonded and a flip-chip VCSEL module, 2) between a single-VCSEL and an 8/spl times/8 VCSEL module, and 3) between a bottom-cooled and a top-cooled module.

A method for automatically displaying map symbols

Abstract: A method for automatically displaying map symbology in a Geographic Information System. In the method, a computer (18) retrieves records (21, 22 and 23) from a data base (20) for each map feature that lies within the extent of the displayed portion (42) of the map (15). The records (22) for point features are organized in 'flat' structures (48) where each map feature is represented by a single symbol (16), and in multi-level 'hierarchical' structures (54) where each feature is represented by a hierarchy of symbols (16) representing different resolutions of the map features. For a hierarchical symbol structure, the level of records retrieved (62) by the computer is determined by the scale (44) of the map displayed to the screen (14). The computer determines (64), for each symbol (16) at the particular map scale (44), whether the symbol extensively overlaps any other symbol. The symbols that overlap significantly are modified (66) to reduce the clutter by either merging (98) the overlapping symbols into a single symbol including a numeric identifier or replacing (124) the symbol and its siblings by the single parent symbol in the hierarchy. The symbols (16) from the modified records (22) are displayed (70) to the screen (15).

Electrically driven bistable mechanical actuator

Abstract: A mechanical actuator includes an annular electromagnet and a ferromagnetic plunger disposed within a bore of the electromagnet and slidable therein. A first permanent magnet is positioned outside of the bore and in facing relation to a first end face of the plunger, and a second permanent magnet is positioned outside of the bore and in facing relation to the second end face of the plunger. The plunger is slidable in the bore between a first position with the first end face adjacent to the first permanent magnet and a second position with the second end face adjacent to the second permanent magnet. Activation of the electromagnet with the current flowing in a first direction drives the plunger toward the first permanent magnet, where it is retained. Activation of the electromagnet with the current flowing in a second (opposite) direction drives the plunger away from the first permanent magnet and toward the second permanent magnet, where it is retained.

Method and device for coin diameter discrimination

Abstract: A coin diameter discriminating device wherein a coin is received in a coin transport mechanism which is rotated by a motor at an accurately controlled angular velocity. By such arrangement, the coin is carried along a predetermined path at an accurately controlled or regulated velocity past at least one optical sensor that provides a change of state output upon detecting an edge of the coin. The sensor is arranged to start a time counter that is stopped by a predetermined reference event such as the coin transport mechanism having rotated to a predetermined angular orientation. The time count in the counter therefore corresponds to the angular orientation of the coin transport mechanism at the time of detecting the coin edge, which also accurately corresponds to the diameter of the coin. The time count is then compared to corresponding time count ranges each of which relates to known standards of an acceptable coin denomination.

Gun sight system for a military vehicle

Abstract: An optical gun sight system for an M1A2 Abrams Main Battle Tank supported in a lower housing which may be attached to the fixed internal upper housing in the turret of the tank. An adapter plate is provided which has two sets of openings, one to align with the openings in the upper housing and the other to align with openings in the lower housing. An alignment mechanism allows for fine adjustment of the lower housing relative to the upper housing. Operating buttons, knobs and filter wheel are conveniently located on or beneath the front face of the lower housing. A thermal imaging system includes an objective lens for receiving an image of a target object, an eyepiece lens for viewing the image of the object, and a compensator lens movably located between the objective and eyepiece lenses for providing a thermal image of the object. The system includes a servo motor control system for controlling the position of the compensator lens based upon temperature, range and field of view to provide an accurate thermal image of the object.

Field emission display with focus grid and method of operating same

Abstract: A field emission display having a plurality of pixels is disclosed wherein each pixel includes a cathode with a plurality of field emitters and corresponding gate electrodes to emit electrons, an anode distally disposed with respect to the cathode, the anode and the cathode capable of having a voltage difference greater than 6000 volts, and a focus grid disposed between the anode and the cathode, the focus grid having an aperture and disposed in proximity with the cathode to focus electrons from the plurality of field emitters of the cathode toward the anode. With such an arrangement, a field emission display is provided having greater brightness and efficiency.

Ferroelectric aerogel composites for voltage-variable dielectric tuning, and method for making the same

Abstract: Ferroelectric composites are prepared by sol-gel derived procedures. The present invention utilizes the sol-gel process (1) to form a gel in a mold of the desired size and shape, (2) to dry the gel using a supercritical fluid extraction, (3) to sinter the dried gel to a crystalline ceramic, and finally (4) to impregnate the pores with a low loss polymer. The aerogel composition may be a barium titanate-based composition such as barium strontium titanate (BST). Making a ferroelectric aerogel composite provides a unique and novel means of fully exploiting the voltage- and/or frequency-tunable properties of certain compositions by maximizing their desirable properties and minimizing their undesirable characteristics such as loss at operational frequencies.

Uniform-brightness, high-gain display structures and methods

Abstract: A uniform-brightness, high-gain projection screen (102) is especially suited for reflecting radiation from a projector (104, 106) to a viewer (112) who is spaced from the projector along a projection axis (108, 110). The screen is formed with a plurality of reflective faces (120, 122) that each form at least a portion of a ring that is transverse to the projector axis, have different spacings from the projector and are axially tilted to set the projector-face angle (132) equal to the viewer-face angle (134). The faces are preferably defined by a plurality of tiles (150) that are bonded to the interior of a projection dome (103) such as a flight simulator dome.

Apparatus for supporting circuit cards in slot locations

Abstract: A chassis having a unique configuration is provided along with card guide assemblies having predefined configuration types for selective installation in the chassis. The guide assemblies, when installed within the chassis, enable circuit cards having varying standard dimensions to be mounted and secured within the chassis regardless of slot location. A first type of card guide assembly is mounted at the end of a plurality of slot locations a predetermined first standard distance apart to enable cards having a first length and one of a number of depths to be installed. A second type card guide assembly is mounted between the opposed first card guide assemblies at any slot location a second predetermined standard distance from one of the first guide assemblies to form a slot partition and enable the installation of cards having a second length shorter than the first length and one of the number of depths.

Digital-to-analog converted (DAC) and method that set waveform rise and fall times to produce an analog waveform that approximates a piecewise linear waveform to reduce spectral distortion

Abstract: A DAC converts a sequence of digital codewords into an approximately piecewise linear analog waveform that follows rising and falling edges between plateau levels The DAC processes, in parallel, each bit of the codewords to produce component waveforms that are weighted according to their bits significance and summed together to produce the piecewise linear analog waveform Waveform shaping circuits control the rise and fall times of each component waveform so that the analog waveform's rising and falling edges settle to within a desired error bound of a linear output ramp whose slope is a function of the difference between successive codewords and the rise or fall times The rise and fall times are preferably approximately the same Limiting switches control the plateau levels of the component waveforms so that the analog waveform's plateaus settle to within the desired error bound of the ideal values represented by the codewords The linear region of the limiting switches are expanded to maintain the linearity of the rising and falling edges established by the waveform shaping circuits

Configurable interface module

Abstract: A configurable interface module particularly suited for processing of digital and analog information includes at least one field programmable gate array (44, 46, 48) mounted on a mezzanine board (30) to provide functional flexibility and not requiring an additional slot in a computer chassis. In a preferred embodiment, the module is utilized to process weather information and performs the functions of demodulation, bit and frame synchronization, and FIFO buffer control. The gate arrays may be reprogrammed to implement either AM demodulation or BPSK demodulation or adapted to process other types of information, such as telemetry information.