By Topic

Aerospace Applications Conference, 1990. Digest., 1990 IEEE

Date 4-9 Feb. 1990

Filter Results

Displaying Results 1 - 25 of 28
  • A command and data system for concurrent handling of multiple payloads

    Publication Year: 1990, Page(s):1 - 10
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (641 KB)

    A system concept to improve the state of practice in space-based payload support and provide data processing, command and telemetry, and friendly crew interface for Shuttle experiments is introduced. It is also designed to serve as a mission support system on the ground. A prototype of the system was developed in the laboratory and demonstrated in real time. It includes custom-made units such as t... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Battle management onboard processing for SDI

    Publication Year: 1990, Page(s):11 - 19
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (524 KB)

    The problem of the SDI (strategic defense initiative) onboard battle management processing is addressed. A brief overview of the general requirements for wartime space processing is presented, and the processing requirements which are specific to the battle management problem are discussed. Processor architecture and implementation using 05- mu m very high speed integrated circuit II (VHSIC II) su... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Spatial acquisition of satellite transmissions in the presence of ephemeris errors

    Publication Year: 1990, Page(s):21 - 30
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (749 KB)

    One component of the Automated Remote Tracking Station (ARTS) Program is the ability to acquire a satellite transmission automatically. Under abnormal conditions, where the ephemeris is not precisely known, it is necessary to ensure that the antenna is positioned on the main beam prior to engaging monopulse tracking to complete the acquisition. The ARTS program uses an automated main beam acquisit... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Validating GPS software and implications for the future

    Publication Year: 1990, Page(s):31 - 58
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (953 KB)

    An overview of the GPS (global positioning system) is provided. Details are presented on the navigation message that is utilized by GPS user equipment (UE) to provide the user his position, time, and velocity. In order to reduce the adverse impact on GPS users of hosting a new software (S/W) release (OR 5.10) on the operational computer at the Master Control Station System, a multiphased test plan... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Polarization selective reflectors for spacecraft applications

    Publication Year: 1990, Page(s):61 - 71
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (518 KB)

    The design and development of a K-band polarization selective reflector (PRS) system are discussed. Waveguide simulator measurements showed close agreement with parallel wire theory. The radiation pattern measurements of PSR demonstrated almost complete reflection in one polarization with excellent cross-polarization isolation. An offset reflector configuration was chosen for the investigation bec... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Signal degradation of BPSK signal in the presence of CW spur

    Publication Year: 1990, Page(s):73 - 82
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (349 KB)

    The signal degradation of a BPSK (binary phase-shift keying) signal with NRZ (nonreturn to zero) and biphase baseband signaling formats in the presence of CW (continuous-wave) spur is analyzed. CW spur is usually due to unintentional interference, and the degradation is usually small. The degradation is a function of the frequency and phase differences, the signaling format, and the nominal value ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Antenna subsystem for the INTELSAT VII spacecraft

    Publication Year: 1990, Page(s):83 - 92
    Cited by:  Papers (3)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (553 KB)

    A multifunction antenna subsystem consisting of communications and telemetry/command antennas for the INTELSAT VII communications satellite is described. The antenna subsystem design is dictated by a requirement to provide multiple communications links between the Earth and the spacecraft and by a need to track, command, and monitor the spacecraft during all phases of its flight. The eight differe... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Operation principle and loss of blanking pulse of the navigation system on Space Shuttle

    Publication Year: 1990, Page(s):93 - 102
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (505 KB)

    The basic operation principle of the TACAN navigation system on the Space Shuttle is described. An issue of interest to NASA engineers is the effect of the loss of the blanking pulse in the system. A simplified operation model of the shuttle TACAN receiver is presented. The effect is analyzed from the interference point of view in case of blanking pulse loss.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Automated gisting systems for voice communications

    Publication Year: 1990, Page(s):103 - 115
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (437 KB)

    It is pointed out that the detection of a limited number of key words in voice communications, combined with nonlinguistic cues and situation knowledge, holds out the promise for automatic extraction of the general content or gist of the transmitted messages. A systems-level description of an end-to-end automatic gisting system for screening voice communications is presented. The emphasis is on id... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Tethered satellite antenna arrays for passive radar systems

    Publication Year: 1990, Page(s):117 - 125
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (385 KB)

    The possibility of using long (multi-kilometer) tethers in orbit, particularly for passive radar surveillance, is examined. Such devices could use the echo derived from common UHF and VHF sources (primarily commercial radio and television stations) for target range and Doppler estimation. Such systems could provide high gain (50-60 dB) and high spatial resolution at low frequencies. Configurations... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Propagation characteristics of optical fiber structures with arbitrary shape and index variation

    Publication Year: 1990, Page(s):127 - 136
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (483 KB)

    The application of the scalar wave-fast Fourier transform (SW-FFT) technique to the computation of the propagation characteristics of some complex optical fiber structures is presented. The SW-FFT technique is based on the numerical solution of the scalar wave equation by a forward-marching fast Fourier transform method. This solution yields the spatial configuration of the fields as well as its m... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Sun gate for Galileo spacecraft attitude control

    Publication Year: 1990, Page(s):137 - 146
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    The combination of a Sun sensor called a Sun gate (SG) and a digital programmable signal processor on the Galileo spacecraft attitude and articulation control subsystem (AACS) will orient the rotation axis of the spacecraft toward the Sun to satisfy a new requirement imposed by the new spacecraft trajectory. The combination will continuously monitor the pointing direction of the rotation axis, and... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An electronically tuned, stable 8415 MHz dielectric resonator FET oscillator for space applications

    Publication Year: 1990, Page(s):147 - 156
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (547 KB)

    A voltage-controlled 8415-MHz FET oscillator stabilized by a dielectric resonator is described. The oscillator provides over 3.2-MHz linear electronic tuning range with a flat power output equal to +1.8 dBm (27 degrees C, nominal), a single-sideband noise-to-carrier ratio of -68 dBc/Hz at 1 kHz off carrier, and a frequency-temperature coefficient of 0.54 parts per million/ degrees C over a -24 deg... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • SAPT units turn-on in an interference-dominant environment

    Publication Year: 1990, Page(s):157 - 169
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (531 KB)

    A standalone pressure transducer (SAPT) is a credit-card-sized smart pressure sensor inserted between the tile and the aluminum skin of a Space Shuttle. Reliably initiating the SAPT units via RF signals in a prelaunch environment is a challenging problem. Multiple-source interference may exist if more than one GSE (ground support equipment) antenna is turned on at the same time to meet the simulta... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Digitally programmable voltage-to-frequency converter

    Publication Year: 1990, Page(s):171 - 179
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (285 KB)

    The author presents a novel design approach for a VFC (voltage-to-frequency converter) based on a digital technique which utilizes an analog-to-digital converter, programmable read-only-memory, latch, divide-by-n chip, and associated control circuitry. The unique aspect of this design is the fact that the ratio between the maximum and minimum frequency rates is programmable by the user, and the pe... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Simulated annealing with dynamic perturbations: a methodology for optimization

    Publication Year: 1990, Page(s):181 - 191
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (687 KB)

    The authors review the traditional simulated annealing algorithm, presenting physical analogies of the process and a formal statement of the algorithm, and propose a modification to the classical simulated annealing process through the use of dynamic perturbation functions. This modification is shown to yield a significant improvement in performance for the 50-city traveling salesman problem. The ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Packet communications services for the Space Station Freedom

    Publication Year: 1990, Page(s):193 - 200
    Cited by:  Papers (2)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (635 KB)

    The preliminary design of the space-to-ground packet communications services that have been recommended for the Space Station Freedom Manned Base (SSFMB) is discussed. The packet communications services between the Space Station Freedom and the ground control centers are considered. The packet communications services described include path service for the unacknowledged and unconfirmed delivery of... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Communications protocol stacks for the Space Station Freedom

    Publication Year: 1990, Page(s):201 - 207
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (469 KB)

    Some of the aspects of the communications protocol stacks that have been recommended for the packet communications services for the Space Station Freedom Program are discussed. Particular attention is given to the protocol stacks that support the two space-to-ground packet communications services, the path and internet services. The protocol stacks of the subnetworks and gateways that connect onbo... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Ada to SQL interfaces for C/sup 3/I applications

    Publication Year: 1990, Page(s):209 - 221
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (948 KB)

    The implementation considerations for Ada to Structured Query Language (SQL) interfaces in command, control, communications, and intelligence (C/sup 3/I) applications are described. In particular, four aspects of these interfaces are considered: program portability, query optimization, null value treatment, and host variable semantics. Three different proposals for a standard Ada-to-SQL interface ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Application of a DBMS in a large command, control, and information system

    Publication Year: 1990, Page(s):223 - 233
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (648 KB)

    The application of a relational DBMS (database management system) to the development, generation, and operation of NATO's Northern European Command (NEC) Command, Control, Information System (CCIS) is discussed. The DBMS (Britton Lee's back-end processor IDM 500) is used both as a component of the deliverable application system and as a support tool for offline development work. An overview of the... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A flexible data handling concept

    Publication Year: 1990, Page(s):235 - 245
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (451 KB)

    A data-handling and control concept which uses a data bus to integrate digital data in satellites is presented. Onboard sensor data are processed to generate messages that utilize a data bus to provide flexible interconnections with other onboard processors and, through a communications network, to other satellites and the ground. A design that can be tailored to meet the requirements of different... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Continuous time Markov chain model for token ring local area network

    Publication Year: 1990, Page(s):247 - 251
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (301 KB)

    A continuous-time Markov chain model of a token ring network with each node having a finite buffer is presented. A model is developed to analyze the token ring network by considering the exponential distribution of message length and token transmission time. Throughput, delay, probability of blocking, and throughput-delay tradeoffs have been derived. A comparative evaluation of the performance of ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Rapid prototyping of large command, control, communications and intelligence C/sup 3/I systems

    Publication Year: 1990, Page(s):253 - 263
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (746 KB)

    Rapid prototyping is examined from three points of view: management, rapid analysis, and design. A rapid prototyping approach is presented for end-user requirements of large, data-intensive, command and control (C/sup 2/); command, control, communications and intelligence (C/sup 3/I); and command and control information systems (CCIS). It is noted that participatory management, highly motivated pe... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Digital signal processor microchips applied to aerospace control systems

    Publication Year: 1990, Page(s):265 - 279
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (653 KB)

    The author reviews the requirements placed on the controller in real-time aerospace control applications and compares them with those found in the digital signal processing (DSP) field. The application of a family of powerful DSP microchips to the field of aerospace control systems is studied. An example of a simple control system is used to present the basic concepts and to show the effects of da... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • US leadership loss in microelectronics could seriously impact aerospace applications

    Publication Year: 1990, Page(s):281 - 312
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1857 KB)

    The authors analyse changes in US and Japanese semiconductor industry. They consider how changes in the industry have affected, and will continue to affect, aerospace design engineers. The emphasis is on the advanced microelectronic products. Attention is focused on the high reliability and extended temperature range devices as well as on the full military specification and radiation-hardened (rad... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.