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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.
371

FFT Bit Templating – A Technique for Making Amplitude and Frequency Measurements of a BPSK Modulated Signal

Shockey, Bruce 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / In many spacecraft receiver applications, the Fast Fourier Transform (FFT) provides a powerful tool for measuring the amplitude and frequency of an unmodulated RF signal. By increasing the FFT acquisition time, tiny signals can be coaxed from the noise and their frequency measured by determining which frequency bin the signal energy appears. The greater the acquisition time, the narrower the bin bandwidth and the more accurate the frequency measurement. In modern satellite operations it is often desirable for the receiver to measure the frequency of a carrier which is modulated with BPSK data. The presence of the BPSK data limits the FFT acquisition time since the signal may switch polarities a number of times while the FFT samples are being acquired. This polarity switching spreads the signal energy into multiple frequency bins making frequency measurement difficult or impossible. The Bit Templating Technique, used for the first time in the CMC Electronics Cincinnati TDRSS / BPSK Spacecraft Receiver, collects the modulated waveform energy back into a signal bin so that accurate amplitude and frequency information can be calculated.
372

BASELINE COMMUNICATIONS SYSTEM FOR A SMALL SATELLITE

Orozco, Gina 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The NMSUSat is part of the AFRL/NASA University Nanosatellite program. The constellation will consist of a main microsatellite that will have a command link from ground and a telemetry link to ground while a picosatellite will act as a sensor reporting data to the microsatellite. Innovative command and data handling will be incorporated at low cost and greater accessibility. In this paper we present the necessary communications and control architecture for the space segment and the ground segment of the nanosatellite.
373

A DYNAMIC MULTI-PROTOCOL INTERFACE FOR TT&C SATELLITE BASEBAND PROCESSOR

Mitchell, Marcella B., Thomas, Alain 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents the architecture of a new dynamic multi-protocol network interface implemented on a TT&C satellite baseband processor. Today Ethernet is the main connection of the equipment in a satellite system. Various protocols are necessary to optimize support of data exchange and are implemented using several supports such as Serial lines, Ethernet or Internet. The capability to dynamically switch from one service to another, using the most adapted interface, is the key factor for a multi-mission, multi-satellite system.
374

STOPPING LAUNCH PAD DELAYS, LAUNCH FAILURES, SATELLITE INFANT MORTALITIES AND ON ORBIT SATELLITE FAILURES USING TELEMETRY PROGNOSTIC TECHNOLOGY

Losik, Len 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 / Telemetry Prognostics is Failure Prediction using telemetry for launch vehicle and satellite space flight equipment to stop launch failures, launch pad delays, satellite infant mortalities and satellite on orbit failures. This technology characterizes telemetry behaviors that are latent, transient, and go undetected by the most experienced engineering personnel and software diagnostic tools during integration and test, launch operations and on orbit activities stopping launch pad delays, launch failures, infant mortalities and on orbit failures. Telemetry prognostics yield a technology with state-of-the-art innovative techniques for determining critical on-board equipment remaining useful life taking into account system states, attitude reorientations, equipment usage patterns, failure modes and piece part failure characteristics to increase the reliability, usability, serviceability, availability and safety of our nation’s space systems.
375

SYNCHRONOUS COMMAND GENERATOR IN A SINGLE STANDALONE CHASSIS FOR SPINNING SATELLITES

Boulinguez, Marc, Carlier, Pierre-Marie 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Designed for unattended 24 hours-a-day operation in automatic system environments, the 3801 TT&C Digital Processor Unit is the key communication unit for ground stations operating spacecraft, from integration to positioning phase and in-orbit operation. Its architecture and technology concept combine high performance, compactness and modularity. The 3801 TT&C Digital Processor Unit supports multiple formats in a single stand-alone chassis, and incorporates extensive interfacing and functional provisions to maximize effectiveness, reliability and dependability. It supports a number of configurations for satellite control applications and performs :* • Telemetry IF demodulation and transmission of data to a high-level communication interface, with time tagging and display of decommutated parameters, • Command generation, with FSK or PSK and FM or PM modulation at 70 MHz, • Ranging measurements and calibration using ESA, INTELSAT and major standards (tones and codes). In addition, the 3801 TT&C Digital Processor supports a Synchronous Command Generator for spinning satellite in a single stand-alone chassis and includes : • FM signal discrimination, for satellite spin reference information coming from the Telemetry Reception channel, • Synchronization Controller for providing the reference « top » for the transmission of the synchronous tones, • Tones Generation of frequency tones towards the PM/FM Modulator.
376

Satellite meteorology in the cold war era: scientific coalitions and international leadership 1946-1964

Callahan, Angelina Long 13 January 2014 (has links)
In tracing the history of the TIROS meteorological satellite system, this dissertation details the convergence of two communities: the DOD space scientists who established US capability to launch and operate these remote sensing systems and the US Weather Bureau meteorologists who would be the managers and users of satellite data. Between 1946 and 1964, these persons participated in successive coalitions. These coalitions were necessary in part because satellite systems were too big—geographically, fiscally, and technically—to be developed and operated within a single institution. Thus, TIROS technologies and people trace their roots to several research centers—institutions that the USWB and later NASA attempted to coordinate for US R&D. The gradual transfer of persons and hardware from the armed services to the non-military NASA sheds light on the US’s evolution as a Cold War global power, shaped from the “top-down” (by the executive and legislative branches) as well as the “bottom-up” (by military and non-military scientific communities). Through these successive coalitions, actor terms centered on “basic science” or the circulation of atmospheric data were used to help define bureaucratic places (the Upper Atmospheric Rocket Research Panel, International Geophysical Year, NASA, and the World Weather Watch) in which basic research would be supported by sustained and collaboration could take place with international partners.
377

Capture Method for Spread Spectrum Aloha Signals

Weibing, Fan, Qishan, Zhang 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The concept and model of Spread Spectrum ALOHA (SS-ALOHA), as an important subject to develop dual-purpose satellite system in China, are described in this paper. The new synchronous code format and method for capturing the SS-ALOHA signals are presented and the process of correlation with surface-audio wave (SAW) is shown. The diagram of fast acquisition system and the results of experiment are given.
378

A SMALL SATELLITE FOR MEASURING ATMOSPHERIC WATER CONTENT; PART I, DOWNLINK AND COMMAND SYSTEMS

Cramer, J., Biggs, B., Contapay, J., Iskandar, A., Mahan, A. 10 1900 (has links)
International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This student paper was produced as part of the team design competition in the University of Arizona course ECE 485, Radiowaves and Telemetry. It describes a telemetering system design recommendation for a small satellite capable of conducting scientific research regarding atmospheric water content. This paper focuses on the subsystems required to send the scientific data and monitored operational conditions from the satellite to, and commands to the satellite from, a ground station. A companion paper (Hittle, et. al.) focuses on the cross-link subsystem required to make the scientific measurements and on the power generation and distribution subsystem for the satellite.
379

REENGINEERING A TRADITONAL SPACECRAFT CONTROL CENTER

Knauer, Christian, Nötzel, Klaus Ralf 10 1900 (has links)
International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Deutsche Telekom is operating various communication satellites since 1989. The SCC (spacecraft control center) is located near Frankfurt / Germany. The entire system is based on antenna/RF equipment, baseband and computer software packages running on a computer network of different machines. Due to increased maintenance effort the old baseband system needed to be replaced. This also had effects to the computer system, especially to the M&C. The aim was to design the entire system in a way that the operation effort in costs aspects and human intervention are minimized. This paper shows the successful real world project of reengineering a traditional spacecraft control center (SCC). It is shown how a fifteen year old hardware (baseband system) and software design was replaced by a modern concept during normal operations. The new software packages execute all necessary tasks for spacecraft- and ground station control. The Monitor and Control System (M&C) is a database driven design (FRAMTEC, from CAM Germany).
380

A SMALL SATELLITE FOR MEASURING ATMOSPHERIC WATER CONTENT; PART II, CROSSLINK AND DATA COLLECTION

Hittle, K., Braga, A., Ackerman, R., Afouni, F., Khalid, H., Coleman, J., Keena, T., Page, A. 10 1900 (has links)
International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This student paper was produced as part of the team design competition in the University of Arizona course ECE 485, Radiowaves and Telemetry. It describes a telemetering system design recommendation for a small satellite capable of conducting scientific research regarding atmospheric water content. This paper focuses on the cross-link subsystem required to make the scientific measurements and on the power generation and distribution subsystem for the satellite. A companion paper (Cramer, et. al.) focuses on the subsystems required to send the scientific data and monitored operational conditions from the satellite to, and commands to the satellite from, a ground station. The central objective is to validate a new technique for precisely measuring water vapor profiles of clouds throughout the troposphere. This method involves the detection of 4 SHF tones sent out from the International Space Station (ISS), providing high-resolution amplitude and phase delay data.

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