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Aerospace Applications Conference, 1993. Digest., 1993 IEEE

Date Jan. 31 1993-Feb. 5 1993

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Displaying Results 1 - 20 of 20
  • Instrumentation and control system design for the Weapons Engineering Tritium Facility, Los Alamos National Laboratory

    Publication Year: 1993 , Page(s): 227 - 236
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (597 KB)  

    The instrumentation and control system (ICS) of the Weapons Engineering Tritium Facility (WETF), a facility for processing tritium for various applications and experiments at the Los Alamos National Laboratory, is described. The ICS integrates all of the WETF process subsystems into a single cohesive unit. The hardware and software of the ICS provide a broad range of functions for the WETF operati... View full abstract»

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  • A brief discussion of EMI shielding materials

    Publication Year: 1993 , Page(s): 217 - 226
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (552 KB)  

    The concepts and materials for reducing electromagnetic interference (EMI) are reviewed. Configurations that are and are not susceptible to EMI are discussed. EMI-reducing materials (absorbers) that are dielectric or magnetic, uniform or nonuniform, chiral or nonchiral, and natural or synthetic are discussed. Absorber design depends on the frequency range, the quantity of shielding required, and t... View full abstract»

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  • Tin whiskers: a case study

    Publication Year: 1993 , Page(s): 207 - 215
    Cited by:  Papers (4)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (814 KB)  

    Pure electroplated tin is susceptible to the growth of fibrous whiskers that can produce short circuits and, under some conditions, vacuum metal arcs capable of sustaining hundreds of amps. Typical whiskers are 3-4 mu m in diameter and approach 2 mm in length; they are strong enough to penetrate one layer of conformal coating. The physical and electrical properties of tin whiskers and the reasons ... View full abstract»

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  • On definition and use of systems engineering processes, methods and tools

    Publication Year: 1993 , Page(s): 197 - 205
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (615 KB)  

    A case study on the development and deployment of a systems engineering process for use on commercial avionics systems is discussed. The systems engineering process is presented in the context of the overall product development process, called the common process, which identifies goals, objectives, major milestones and top level activities for the systems engineering, hardware engineering, softwar... View full abstract»

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  • Performance analysis, quality function deployment and structured methods

    Publication Year: 1993 , Page(s): 187 - 195
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (662 KB)  

    Quality function deployment, (QFD), an approach to synthesizing several elements of system modeling and design into single unit, is presented. Behavioral, physical, and performance modeling are usually considered as separate aspects of system design without explicit linkages. Structured methodologies have developed linkages between behavioral and physical models before, but have not considered the... View full abstract»

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  • HERCULES attitude processor: gyro data processing system for real-time geolocation of images captured by astronauts

    Publication Year: 1993 , Page(s): 169 - 178
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (768 KB)  

    The HERCULES (hand held, earth oriented, real-time, cooperative, user friendly, location, targeting, and environmental system) attitude processor (HAP), a microprocessor-based gyro attitude data processing system used in the geolocation process, is described. The HAP software and hardware structures are discussed. A worst-case analysis of the design shows that there are no design flaws. The HERCUL... View full abstract»

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  • Space systems overview

    Publication Year: 1993 , Page(s): 133 - 168
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1900 KB)  

    The elements of a space system, presented in a conversational form meant for a broad audience, are reviewed. The rationale of why space is useful for certain missions and each of the elements of a space system are described. The elements are the orbits and constellations, launch vehicles, and the design and construction of the spacecraft. The launch systems discussion emphasizes the enormous amoun... View full abstract»

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  • Cost and reliability study for a large array of small reflector antennas for JPL/NASA Deep Space Network (DSN)

    Publication Year: 1993 , Page(s): 121 - 132
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (554 KB)  

    A study performed to estimate the cost of an array of small aperture reflector antennas to be used instead of or in conjunction with the current large reflector antennas of the JPL/NASA Deep Space Network (DSN) is described. The arrays are used for servicing present and future NASA missions that involve smaller spacecraft with limited power and smaller, lower-gain antennas. The advantages of the a... View full abstract»

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  • Microwave feed systems for NASA's beam-waveguide reflector antennas

    Publication Year: 1993 , Page(s): 109 - 120
    Cited by:  Patents (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (425 KB)  

    The major features of a beam waveguide (BWG) antenna and the variety of feed system configurations that can be used with this type of antenna are described. The first BWG antenna built by NASA (DSS 13), and its microwave feed systems and their major components, such as the low noise amplifiers, passive microwave components, and the frequency selective mirrors used for multiple frequency operation ... View full abstract»

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  • An autonomous antenna for aerospace applications

    Publication Year: 1993 , Page(s): 99 - 108
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (603 KB)  

    A compact shipboard antenna array that provides full hemispherical electronic scan and tracking is described. Using surface acoustic wave (SAW) devices and microstrip variable power combiners (VPCs), the autonomous array can track and receive telemetry data from a submarine-launched Trident II missile just as well as a large mechanically scanned dish antenna. The tracking antenna consists of three... View full abstract»

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  • Wide swath SAR and radar altimeter

    Publication Year: 1993 , Page(s): 87 - 97
    Cited by:  Patents (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (610 KB)  

    The conceptual design and a spaceborne, high-resolution, wide-swath synthetic aperture radar (SAR) and radar altimeter that can be implemented in L, C or X-band or in a combination of bands is described. The design uses active planar array antennas to form multiple independent beams that cover swaths of up to 700 km. A dual C/X-band array can be used. From an altitude of 800 km, up to five beams p... View full abstract»

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  • A cross beam interferometer radiometer for high resolution microwave sensing

    Publication Year: 1993 , Page(s): 77 - 86
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (589 KB)  

    The conceptual design of a cross beam interferometer radiometer (CBIR) for sea surface temperature sensing at 5.0 GHz is described. In a 833-km orbit, the radiometer provides 0.48 K sensitivity with a spatial resolution less than 25 km in a 1561-km swath. The radiometer consists of a pair of rectangular phased arrays in a T configuration. Each array forms ten colinear beams that project ten pairs ... View full abstract»

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  • Sequential mode adaptive array processing

    Publication Year: 1993 , Page(s): 67 - 76
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (422 KB)  

    An approach to operating and processing adaptive arrays to automatically sense and eliminate unwanted signals in the radar echoes while enhancing the reception of the desired target returns is presented. The algorithm is based on synthetic sample aperture radar (SSAMAR) operation and signal processing. No matrix inversion is required, and the weights are computed in a scalar fashion. Jammers are n... View full abstract»

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  • An acousto-optically controlled phased array beamsteering system

    Publication Year: 1993 , Page(s): 57 - 66
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (615 KB)  

    A novel acoustooptic beamsteering control system for monolithic-microwave-integrated-circuit (MMIC)-based phased array antennas that uses parallel optical signal processing is presented. The approach is compatible with existing MMIC digital phase shifter and gain controller designs and offers several advantages over conventional beamsteering control systems. An overview of the system architecture,... View full abstract»

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  • Spurious phase modulation by crystal filters

    Publication Year: 1993 , Page(s): 53 - 56
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (223 KB)  

    A spurious phase modulation (PM) problem discovered during a satellite thermal vacuum test was traced to a supposedly passive component: a crystal filter. While a literature search showed that this phenomenon has been observed in the past, the effect does not seem to be widely known and is a possible problem in some current designs. The PM was noted in a passive four-pole lattice-type crystal band... View full abstract»

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  • Performance results of a 300 degrees linear phase modulator for spaceborne communications applications

    Publication Year: 1993 , Page(s): 43 - 52
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (841 KB)  

    A phase modulator capable of large linear phase deviation, low loss, and wideband operation with good thermal stability is described. The phase modulator was developed for deep space spacecraft transponder (DST) applications at X-band (8.415 GHz) and Ka-band (32 GHz) downlinks. The design uses a two-stage circulator-coupled reflection phase shifter with constant gamma hyperabrupt varactors and an ... View full abstract»

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  • Advanced transponders for deep space applications

    Publication Year: 1993 , Page(s): 21 - 42
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (917 KB)  

    Three architectures for advanced deep space transponders are proposed. The architectures possess various digital techniques such as fast Fourier transform (FFT), digital phase-locked loop (PLL), and digital sideband aided carrier detection with analog or digital turn-around ranging. Preliminary results on the design and conceptual implementation are presented. Modifications to the command detector... View full abstract»

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  • Simulation performance of simultaneous TDRSS support of Space Station and Space Shuttle

    Publication Year: 1993 , Page(s): 11 - 19
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (416 KB)  

    The simulation performance of simultaneous tracking and data-relay satellite system (TDRSS) support of Space Station and Space Shuttle communication is discussed. Eight Ku- and S-band forward and return links are considered. The models and parameters of the systems are described in detail in an accompanying paper (see ibid., p.1-9).<> View full abstract»

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  • Performance modeling of simultaneous TDRSS support of Space Station and Space Shuttle

    Publication Year: 1993 , Page(s): 1 - 9
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (350 KB)  

    Performance modeling of simultaneous tracking and data-relay satellite system (TDRSS) support of existing Space Shuttle and planned Space Station communications is discussed. Eight Ku- and S-band forward and return links are considered. The modeling of each of the communications link includes the modulation format, data rate, convolutional coding, pseudonoise coding, high power amplification, filt... View full abstract»

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  • 1993 IEEE Aerospace Applications Conference Digest [Front Cover]

    Publication Year: 1993
    Save to Project icon | Request Permissions | PDF file iconPDF (20 KB)  
    Freely Available from IEEE