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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.
41

Precise geodetic position determination with the aid of artificial Earth satellites : the geometric solution

Lambeck, Kurt January 1967 (has links)
No description available.
42

Assessment of synchronization in the SDH satellite sector

Van Wyk, Carel Johannes 17 August 2012 (has links)
M.Ing. / The increase of multimedia and broadband communications in recent years has brought about the creation and implementation of synchronousdigital hierarchy (SDH) in the terrestrial network. The implementation of SDH in the satellite sector is a natural extension to improve the current available networks. It will drastically increase the flexibility and usability of the current under-utilized satellite sector. Unfortunately, SDH has still not been implemented in the satellite sector due to certain inherent synchronization problems of SDH and satellites. This thesis investigates some of these synchronization problems. A simulation tool was created that makes an accurate assessment of SDH synchronization in the satellite sector. The tool was used to study SDH links over goestationary (GEO), medium earth orbiting (MEO) and low earth orbiting (LEO) satellites. Various changeable SDH parameters were investigated to determine their influences. Parameters like the bit rate and elastic store length or hysteresis lengths were considered.
43

On some transportation problems involving tethered satellite systems

Amier, Zine-Eddine. January 1987 (has links)
No description available.
44

Optimal cooperative and non-cooperative peer-to-peer maneuvers for refueling satellites in circular constellations

Dutta, Atri January 2009 (has links)
Thesis (M. S.)--Aerospace Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Panagiotis Tsiotras; Committee Member: Eric Feron; Committee Member: Joseph Saleh; Committee Member: Ryan Russell; Committee Member: William Cook
45

The implications of the privatization of space telecommunications on international organizations

Bochinger, Steve. January 1900 (has links)
Thesis (LL. M.)--McGill University, 2000. / Includes bibliographical references (leaves 119-127).
46

On some transportation problems involving tethered satellite systems

Amier, Zine-Eddine January 1987 (has links)
No description available.
47

Determination of eruption temperature of Io's lavas using lava tube skylights

Davies, Ashley Gerard, Keszthelyi, Laszlo P., McEwen, Alfred S. 11 1900 (has links)
Determining the eruption temperature of Io's dominant silicate lavas would constrain Io's present interior state and composition. We have examined how eruption temperature can be estimated at lava tube skylights through synthesis of thermal emission from the incandescent lava flowing within the lava tube. Lava tube skylights should be present along Io's long-lived lava flow fields, and are attractive targets because of their temporal stability and the narrow range of near -eruption temperatures revealed through them. We conclude that these skylights are suitable and desirable targets (perhaps the very best targets) for the purposes of constraining eruption temperature, with a 0.9:0.7-mu m radiant flux ratio <= 63 being diagnostic of ultramafic lava temperatures. Because the target skylights may be small - perhaps only a few m or 10 s of m across - such observations will require a future Io-dedicated mission that will obtain high spatial resolution (<100 mipixel), unsaturated observations of Io's surface at multiple wavelengths in the visible and near-infrared, ideally at night. In contrast to observations of lava fountains or roiling lava lakes, where accurate determination of surface temperature distribution requires simultaneous or near simultaneous (<0.1 s) observations at different wavelengths, skylight thermal emission data are superior for the purposes of temperature derivation, as emission is stable on much longer time scales (minutes, or longer), so long as viewing geometry does not greatly change during that time. (C) 2016 Elsevier Inc. All rights reserved.
48

THE VARIABILITY OF HCN IN TITAN’S UPPER ATMOSPHERE AS IMPLIED BY THE CASSINI ION-NEUTRAL MASS SPECTROMETER MEASUREMENTS

Cui, J., Cao, Y.-T., Lavvas, P. P., Koskinen, and T. T. 13 July 2016 (has links)
HCN is an important constituent in Titan's upper atmosphere, serving as the main coolant in the local energy budget. In this study, we derive the HCN abundance at the altitude range of 960-1400 km, combining the Ion-Neutral Mass Spectrometer data acquired during a large number of Cassini flybys with Titan. Typically, the HCN abundance declines modestly with increasing altitude and flattens to a near constant level above 1200 km. The data reveal a tendency for dayside depletion of HCN, which is clearly visible below 1000 km but weakens with increasing altitude. Despite the absence of convincing anti-correlation between HCN volume mixing ratio and neutral temperature, we argue that the variability in HCN abundance makes an important contribution to the large temperature variability observed in Titan's upper atmosphere.
49

Generalized approach to navigation of spacecraft formations using multiple sensors

Holt, Greg Nate, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.
50

Navigation and control of large satellite formations

Bamford, William Alfred 28 August 2008 (has links)
Not available / text

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