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Aerospace and Electronic Systems Magazine, IEEE

Issue 6 • Date June 2003

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Displaying Results 1 - 7 of 7
  • Commercial aviation VDL choices

    Page(s): 15 - 20
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (456 KB)  

    The purpose of this study was to analyze digital data link communications technologies in a line-of-sight environment. Because there is a global debate over selecting the next generation VHF data link (VDL) technology, this paper evaluates each of them for the terminal and enroute airspace only. First, this study provides a historical review of the purpose of data link applications; second, how the current system is failing to meet today's requirements, leading to problems within the US National Air Space (NAS); third, a technical and economic analysis of VDL technologies; and last, a recommendation for selecting a VDL technology. View full abstract»

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  • Collaborative testing & support via the Internet

    Page(s): 25 - 29
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (461 KB)  

    The Internet and its current infrastructure provide many opportunities to exploit improved electronics testing by increasing collaboration among individuals worldwide. This paper proposes several ways to take advantage of the ubiquitous Internet infrastructure, its applications, and increasing network bandwidth to better share knowledge between engineering and test technicians, and to build and maintain a network of knowledge sharing among test and maintenance technicians in geographically separated units. Current Internet infrastructure applications that are available and being used in an ad hoc manner are email, instant messaging, video conferencing, and remote control of PCs. These applications can be used by the military to integrate and enhance communications methods and improve the sharing of data as well as remote control of automatic test equipment by engineers providing diagnostic assistance. Knowledge management techniques will be exploited to provide capture of and better access to "head knowledge" which typically stays within an individual technician or engineer. Collection of repair and test data in real-time from geographically dispersed locations can be implemented via the Internet. Engineering can be more responsive in updating TPS software by having more information and, in turn, distribute the updates via the Internet by providing access to a secure server. View full abstract»

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  • Information technology security using cryptography

    Page(s): 21 - 24
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (330 KB) |  | HTML iconHTML  

    It is widely known that information technology applications should be secured. During the last years, special efforts have been applied to achieve a great level of security. These efforts have increased security in some aspects, such as cryptographic algorithms and authentication techniques, etc. But many other security holes have appeared in these applications, making the improvements achieved a "waste of time and money". In this paper, some of these security holes are exposed. Using security hardware modules can overcome some of these holes, if they are designed according to the applications specification. View full abstract»

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  • Timekeeping at the US Naval Observatory

    Page(s): 9 - 14
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (629 KB)  

    No one can stop time, but time can stop a system. Users need to be aware of the different flavors of time, depending upon their needs. Most systems require that all their components be on common time (synchrony), but they cannot keep them on time unless they are also on a common frequency (syntony). Other systems simply require syntony. The US Naval Observatory (USNO) is the timing reference for GPS. Its master clock (MC) is based upon 72 HP5071 cesium and 17 hydrogen maser frequency standards in three buildings at two sites, and their data are used to generate UTC (USNO). The USNO disseminates and distributes the time not only via GPS, but also with Loran, network time protocol (NTP), and two-way-satellite time transfer (TWSTT). Our emphasis is on robustness through repeated calibration and multiplicity of systems, and we recommend this for our users as well. Further details and explanations of our services can be found on: http://tycho.usno.navy.mil, or by contacting the author directly. View full abstract»

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  • Flight-critical distributed systems: design considerations [avionics]

    Page(s): 30 - 36
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (569 KB)  

    With the proliferation of so-called "smart" components and the availability of small, low-cost, and high-speed data networks, avionics that have traditionally been centralized are becoming distributed. A distributed approach offers many potential benefits, such as reduced development time and cost, simplified system installation, increased flexibility for system expansion or modifications, and greater reuse of proven components. The distributed approach can also reduce the risk associated with design errors by splitting complex hardware and software into more manageable components. However, distributed systems also introduce new challenges in meeting real-time deadlines and providing fault tolerance. This paper examines the many design considerations and identifies the strengths and weaknesses of each. Emerging automotive drive-by-wire alternatives are compared for application to aerospace systems. This paper is based on a Draper Laboratory-sponsored effort to look at flight-critical distributed systems and to evaluate emerging hardware and software for building them. View full abstract»

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  • Hypothesis management for information fusion

    Page(s): 3 - 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (487 KB)  

    The efficient management of large collections of fusion hypotheses presents a critical challenge for scaling high-level information fusion systems to solve large problems. We motivate this challenge in the context of two Alphatech research projects, and discuss several partial solutions. A recurring theme is the exploitation of space-efficient, factored representations of multiple hypotheses to enable an efficient search for good hypotheses. View full abstract»

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  • Nature's efficient energy production, storage, and data processing

    Page(s): 37 - 40
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (325 KB)  

    Converting the solar energy received on the surface of the Earth has not been practical with heat engines because of the low density of this energy. On a clear bright day in the summer, the sun generally delivers less than 80 W per square foot. Also, heat engines are prohibited from exceeding the Carnot-cycle efficiency limit. On the other hand, plants perform their energy conversion electrochemically, and, hence, are not limited by the Carnot-cycle. They use solar energy to produce useful fuels that range from corn-cobs and maple syrup to pitch and firewood. However, they have an extremely complicated process control that uses blue and red parts of the visible solar spectrum to extract hydrogen from water and carbon from carbon dioxide to make hydrocarbons. They do not need precious-metal catalysts; however they run complex data processing programs in which stored instructions control electrochemical reactions and also cause growth and production of needed products to occur when needed. View full abstract»

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Aims & Scope

The IEEE Aerospace and Electronic Systems Magazine publishes articles and tutorials concerned with the various aspects of systems for space, air, ocean, or ground environments.

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Meet Our Editors

Editor-in-Chief
Teresa Pace, PhD EE
Chief Engineer SenTech
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