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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Spectrum Stewardship Through Best Source Selection

Gerstner, Grant, Lillevold, Hans 10 1900 (has links)
ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / With the increasing demand on available frequencies used for Telemetry transmission, it is important for the test ranges to be good stewards of the spectrum. One method is a new use of Best Source Selection. This method consists of placing data-quality encapsulators at the output of each of the TM receivers used. This system works without the need to use pattern detect which allows for the use of Best Source Selection without the need for decrypting the data. In conjunction with new system architecture, this setup is how the Atlantic Test Range is using best source selection in the future.
2

Knowledge Integration to Overcome Ontological Heterogeneity: Challenges from Financial Information Systems

Firat, Aykut, Madnick, Stuart E., Grosof, Benjamin 01 1900 (has links)
The shift towards global networking brings with it many opportunities and challenges. In this paper, we discuss key technologies in achieving global semantic interoperability among heterogeneous information systems, including both traditional and web data sources. In particular, we focus on the importance of this capability and technologies we have designed to overcome ontological heterogeneity, a common type of disparity in financial information systems. Our approach to representing and reasoning with ontological heterogeneities in data sources is an extension of the Context Interchange (COIN) framework, a mediator-based approach for achieving semantic interoperability among heterogeneous sources and receivers. We also analyze the issue of ontological heterogeneity in the context of source-selection, and offer a declarative solution that combines symbolic solvers and mixed integer programming techniques in a constraint logic-programming framework. Finally, we discuss how these techniques can be coupled with emerging Semantic Web related technologies and standards such as Web-Services, DAML+OIL, and RuleML, to offer scalable solutions for global semantic interoperability. We believe that the synergy of database integration and Semantic Web research can make significant contributions to the financial knowledge integration problem, which has implications in financial services, and many other e-business tasks. / Singapore-MIT Alliance (SMA)
3

ENCRYPTED CORRELATING SOURCE SELECTOR

Reid, Eric 10 1900 (has links)
ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / Modern telemetry and data streams are often encrypted. The majority of range testing activities require multiple ground stations to collect these streams and send them to a central processing location. Each of these streams currently needs to be individually decrypted before best source selection, processing and analysis. Using innovative techniques, it is possible to time correlate these encrypted streams, compare them with each other and create an output stream of better quality than any of the individual streams. This stream can then be decrypted by a single decryption device, greatly reducing cost and complexity.
4

PACKET-BASED TELEMETRY NETWORKS OVER LEGACY SYSTEMS

O’Connell, Tim 10 1900 (has links)
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The telemetry industry anticipates the tremendous potential value of adding full networking capability to telemetry systems. However, much of this potential can be realized while working with legacy equipment. By adding modules that interface transparently to existing equipment, continuous telemetry data can be encapsulated in discrete packets for over the air transmission. Packet fields can include header, sequence number and bytes for error detection and correction. The RF packet is transmitted without gaps through a standard serial interface and rate adjusted for the packet overhead – effectively making packetization transparent to a legacy system. The receiver unit performs packet synchronization, error correction, extraction of stream quality metrics and re-encapsulation of the payload data into an internet protocol (IP) packet. These standard packets can then be sent over the existing network transport system to the range control center. At the range control center, the extracted stream quality metrics are used to select the best telemetry source in real-time. This paper provides a general discussion of the path to a fully realized, packet-based telemetry network and a brief but comprehensive overview of the Hypernet system architecture as a case study.
5

Multipath Mitigation for Aeronautical Telemetry with Multiple Antennas

Williams, Ian E. 10 1900 (has links)
ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Frequency selective multipath is a key performance limiter for aeronautical telemetry applications. Our research explores multipath mitigation techniques with ARTM Tier-1 waveforms using linear adaptive filters, multiple receive antennas and error-based best source selection. Single antenna adaptive equalization alone is unable to substantially improve performance under certain channel conditions. Analytical investigations demonstrate that nonlinear channel phase response is the principal cause of performance loss. In this adverse environment, spatial diversity with multiple receive antennas along with error-based best source selection are capable of improving bit error rate performance by 5dB for each additional antenna.
6

ENHANCING THE PCM/FM LINK - WITHOUT THE MATH

Fewer, Colm, Wilmot, Sinbad 10 1900 (has links)
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Since the 1970s PCM/FM has been the dominant modulation scheme used for RF telemetry. However more stringent spectrum availability as well as increasing data rates means that more advanced transmission methods are required to keep pace with industry demands. ARTM Tier-I and Tier-II are examples of how the PCM/FM link can be enhanced. However these techniques require a significant increase in the complexity of the receiver/detector for optimal recovery. This paper focuses on a quantitative approach to improving the rate and quality of data using existing PCM/FM links. In particular ACRA CONTROL and BAE SYSTEMS set themselves the goal of revisiting the pre-modulation filter, diversity combiner and bit-sync. By implementing programmable adaptive hardware, it was possible to explore the various tradeoffs offered by modifying pulse shapes and spectral occupancy, inclusion of forward error correction and smart source selection. This papers looks at the improvements achieved at each phase of the evaluation.
7

HYPER-X (X-43A) FLIGHT TEST RANGE OPERATIONS OVERVIEW

Lux-Baumann, Jessica, Burkes, Darryl A. 10 1900 (has links)
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The Hyper-X program flew X-43A research vehicles to hypersonic speeds over the Pacific Ocean in March and November 2004 from the Western Aeronautical Test Range, NASA Dryden Flight Research Center, Edwards, California. The program required multiple telemetry ground stations to provide continuous coverage of the captive carry, launch, boost, experiment, and descent phases of these missions. An overview is provided of vehicle telemetry and distributed assets that supported telemetry acquisition, best-source selection, radar tracking, video tracking, flight termination systems, and voice communications. Real-time data display and processing are discussed, and postflight analysis and comparison of data acquired are presented.
8

BEST SOURCE SELECTORS AND MEASURING THE IMPROVEMENTS

Gatton, Tim 10 1900 (has links)
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / After years of tracing the evolution and solutions to finding the best data, I learned that it isn’t best source selection that we all want. What we need is best data selection.
9

TELEMETRY AND SERVICE CONVERGENCE IN MIXED PROTOCOL TEST RANGE NETWORKS

Kovach, Bob 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / In the past few years, an evolution has been occurring in test range network topologies. With the proliferation of IP-based networks at the desktop, range officers are seeking ways to extend IP-based networks to the test range, to derive the cost and operational benefits offered with IP technology. This transition is not without its own set of problems. The operational transition from the traditional, ATM-based ranges to IP-based ranges must be addressed. In many cases, it is desired to maintain the ATM range, and add IP capabilities as time and budget permits. The net result is that frequently a mixed protocol network emerges. Terawave Communications has been developing telemetry transport solutions for both ATM and IP-based networks, along with technology to enable convergence of additional services such as video, voice, and data across test ranges. Terawave has developed a solution for various network topologies from ATM-only and IP-only to mixed protocol implementations, which supports end-to-end interworking of telemetry, video, and additional services over mixed protocol networks. In this paper, Terawave will detail the implementation decisions made in the course of application development, and share a framework for enabling seamless intra- and inter- range communication of telemetry and mixed services.
10

X-33 TELEMETRY BEST SOURCE SELECTION, PROCESSING, DISPLAY, AND SIMULATION MODEL COMPARISON

Burkes, Darryl A. 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / The X-33 program requires the use of multiple telemetry ground stations to provide continuous coverage of the launch, ascent, re-entry and approach phases for flights from Edwards AFB, California, to landings at Dugway Proving Grounds, Utah, and Malmstrom AFB, Montana. This paper will discuss the X-33 telemetry requirements and design, including information on the fixed and mobile telemetry systems, automated best source selection system, processing/display support for range safety officers (RSO) and range engineers, and comparison of real-time data with simulated data using the Dynamic Ground Station Analysis model. Due to the use of multiple ground stations and short duration flights, the goal throughout the X-33 missions is to automatically provide the best telemetry source for critical vehicle performance monitoring. The X-33 program was initiated by National Aeronautics and Space Administration (NASA) Cooperative Agreement No. NCC8-115 with Lockheed Martin Skunk Works (LMSW).

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