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Dissertations / Theses on the topic 'Artificial satellites'

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Published: 4 June 2021

Last updated: 31 July 2024

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1

Amier, Zine-Eddine. "On some transportation problems involving tethered satellite systems." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66256.

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2

Van, Daalen Corné E. "Strategies for the control of a satellite with thruster misalignment /." Link to the online version, 2006. http://hdl.handle.net/10019/281.

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3

Bordi, John Joseph. "The precise range and range-rate equipment (PRARE) and its application to precise orbit determination /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

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4

Demarest, Peter. "Strategies for the maintenance of satellite ground tracks /." Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3008311.

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5

Gilthorpe, Mark S. "Resonance studies of artificial earth satellites." Thesis, Aston University, 1991. http://publications.aston.ac.uk/10658/.

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Orbit determination from artificial satellite observations is a key process in obtaining information about the Earth and its environment. A study of the perturbations experienced by these satellites enables knowledge to be gained of the upper atmosphere, the gravity field, ocean tides, solid-Earth tides and solar radiation. The gravity field is expressed as a double infinite scries of associated Legendre functions (tesseral harmonics). In contemporary global gravity field models the overall geoid is well determined. An independent check on these gravity field harmonics of a particular order may be made by analysis of satellites that pass through resonance of that order. For such satellites the perturbations of the orbital elements close to resonance are analysed to derive lumped harmonic coefficients. The orbital parameters of 1984-106A have been determined at 43 epochs, during which time the satellite was close to 14th order resonance. Analysis of the inclination and eccentricity yielded 6 lumped harmonic coefficients of order 14 whilst analysis of the mean motion yielded additional pairs of lumped harmonics of orders 14, 28 and 42, with the 14"1 order harmonics superseding those obtained from analysis of the inclination. This thesis concentrates in detail on the theoretical changes of a near-circular satellite orbit perturbed by the Earth's gravity field under the influence of minimal air-drag whilst in resonance with the Earth. The satellite 1984-106A experienced the interesting property of being temporarily trapped with respect to a secondary resonance parameter due to the low air-drag in 1987. This prompted the theoretical investigation of such a phenomenon. Expressions obtained for the resonance parameter led to the determination of 8 lumped harmonic coefficients, coincidental to those already obtained. All the derived lumped harmonic values arc used to test the accuracy of contemporary gravity field models and the underlying theory in this thesis.

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6

Stewart, Abbie Marie. "A guide to the establishment of a university satellite program." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.umr.edu/thesis/pdf/THESISfinal_09007dcc8031d8ef.pdf.

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Thesis (M.S.)--University of Missouri--Rolla, 2007.
Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed May 16, 2007) Includes bibliographical references (p. 96-97).

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7

Anderson, Jason Lionel. "Autonomous Satellite Operations For CubeSat Satellites." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/256.

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In the world of educational satellites, student teams manually conduct operations daily, sending commands and collecting downlinked data. Educational satellites typically travel in a Low Earth Orbit allowing line of sight communication for approximately thirty minutes each day. This is manageable for student teams as the required manpower is minimal. The international Global Educational Network for Satellite Operations (GENSO), however, promises satellite contact upwards of sixteen hours per day by connecting earth stations all over the world through the Internet. This dramatic increase in satellite communication time is unreasonable for student teams to conduct manual operations and alternatives must be explored. This thesis first introduces a framework for developing different Artificial Intelligences to conduct autonomous satellite operations for CubeSat satellites. Three different implementations are then compared using Cal Poly's CP6 CubeSat and the University of Tokyo's XI-IV CubeSat to determine which method is most effective.

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8

Stelianos, Haralambos. "The use of commercial Low Earth Orbit satellite systems to support DoD communications." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA326969.

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Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, December 1996.
"December 1996." Thesis advisor(s): Tri T. Ha and Vicente Garcia. Includes bibliographical references (p. 95-97). Also available online.

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9

FERUGLIO, LORENZO. "Artificial Intelligence for Small Satellites Mission Autonomy." Doctoral thesis, Politecnico di Torino, 2017. http://hdl.handle.net/11583/2694565.

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Space mission engineering has always been recognized as a very challenging and innovative branch of engineering: since the beginning of the space race, numerous milestones, key successes and failures, improvements, and connections with other engineering domains have been reached. Despite its relative young age, space engineering discipline has not gone through homogeneous times: alternation of leading nations, shifts in public and private interests, allocations of resources to different domains and goals are all examples of an intrinsic dynamism that characterized this discipline. The dynamism is even more striking in the last two decades, in which several factors contributed to the fervour of this period. Two of the most important ones were certainly the increased presence and push of the commercial and private sector and the overall intent of reducing the size of the spacecraft while maintaining comparable level of performances. A key example of the second driver is the introduction, in 1999, of a new category of space systems called CubeSats. Envisioned and designed to ease the access to space for universities, by standardizing the development of the spacecraft and by ensuring high probabilities of acceptance as piggyback customers in launches, the standard was quickly adopted not only by universities, but also by agencies and private companies. CubeSats turned out to be a disruptive innovation, and the space mission ecosystem was deeply changed by this. New mission concepts and architectures are being developed: CubeSats are now considered as secondary payloads of bigger missions, constellations are being deployed in Low Earth Orbit to perform observation missions to a performance level considered to be only achievable by traditional, fully-sized spacecraft. CubeSats, and more in general the small satellites technology, had to overcome important challenges in the last few years that were constraining and reducing the diffusion and adoption potential of smaller spacecraft for scientific and technology demonstration missions. Among these challenges were: the miniaturization of propulsion technologies, to enable concepts such as Rendezvous and Docking, or interplanetary missions; the improvement of telecommunication state of the art for small satellites, to enable the downlink to Earth of all the data acquired during the mission; and the miniaturization of scientific instruments, to be able to exploit CubeSats in more meaningful, scientific, ways. With the size reduction and with the consolidation of the technology, many aspects of a space mission are reduced in consequence: among these, costs, development and launch times can be cited. An important aspect that has not been demonstrated to scale accordingly is operations: even for small satellite missions, human operators and performant ground control centres are needed. In addition, with the possibility of having constellations or interplanetary distributed missions, a redesign of how operations are management is required, to cope with the innovation in space mission architectures. The present work has been carried out to address the issue of operations for small satellite missions. The thesis presents a research, carried out in several institutions (Politecnico di Torino, MIT, NASA JPL), aimed at improving the autonomy level of space missions, and in particular of small satellites. The key technology exploited in the research is Artificial Intelligence, a computer science branch that has gained extreme interest in research disciplines such as medicine, security, image recognition and language processing, and is currently making its way in space engineering as well. The thesis focuses on three topics, and three related applications have been developed and are here presented: autonomous operations by means of event detection algorithms, intelligent failure detection on small satellite actuator systems, and decision-making support thanks to intelligent tradespace exploration during the preliminary design of space missions. The Artificial Intelligent technologies explored are: Machine Learning, and in particular Neural Networks; Knowledge-based Systems, and in particular Fuzzy Logics; Evolutionary Algorithms, and in particular Genetic Algorithms. The thesis covers the domain (small satellites), the technology (Artificial Intelligence), the focus (mission autonomy) and presents three case studies, that demonstrate the feasibility of employing Artificial Intelligence to enhance how missions are currently operated and designed.

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10

Oiesen, Eric A. "A satellite signal recognition system." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-09052009-040513/.

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11

Marston, Wendy. "Conflict of interests : the ideas, interests and institutions involved in the development of Canadian satellite policy from 1960-1980." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60674.

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This thesis looks at the development of Canadian satellite policy between 1960 and 1980 through a study of the policy decisions relating to Telesat Canada, its specific corporate structure, and mandates and ownership patterns. The analysis draws upon a modified "interplay" model, which examines public policy as an amalgam of interacting ideas, interests and institutions. On the basis of available documents, supplemented by interviews, and supporting secondary analyses, the sometimes contradictory decisions made by the DOC and the CRTC with regards to Telesat's Agreement with the Trans Canada Telephone system during this period are argued to reflect a policy process driven by the interplay of competing views of Telesat's primary purpose and, by extension, competing visions of what constitutes the public interest.

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12

Robertson, Michael James. "Command generation for tethered satellite systems." Available online, Georgia Institute of Technology, 2005, 2004. http://etd.gatech.edu/theses/available/etd-04142005-090018/.

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Thesis (Ph.D.)--School of Mechanical Engineering, Georgia Institute of Technology, 2005.
Singhose, William, Committee Chair ; Banerjee, Arun, Committee Member ; Chen, Ye-Hwa, Committee Member ; Ebert-Uphoff, Imme, Committee Member ; Olds, John, Committee Member. Includes bibliographical references.

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13

Ng, Chun Ki Alfred. "Dynamics of gravity oriented axi-symmetric satellites with thermally flexed appendages." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26727.

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The equations of motion for a satellite with a rigid central body and a pair of appendages deforming due to thermal effects of the solar radiation are derived. The dynamics of the system is studied in two stages: (i) librational dynamics of the central body with quasi-steady thermally flexed appendages; (ii) coupled librational/vibrational dynamics of the spacecraft. Response of the system is investigated numerically over a range of system parameters and effect of the thermal deformations assessed. The study indicates that for a circular orbit, the flexible system can become unstable under critical combinations of system parameters and initial conditions although the corresponding rigid system continues to be stable. However, in eccentric orbits, depending on the initial conditions, thermally flexed appendages can stabilize or destabliIize the system. Attempt is also made to obtain an approximate closed-form (analytical) solution of the problem to quickly assess trends and gain better physical appreciation of response characteristics during the preliminary design. Comparisons with numerical results show approximate analysis to be of an acceptable accuracy for the intended objective. The closed-form solution can be used with a measure of confidence thus promising a substantial saving in time, effort, and computational cost.
Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate

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14

Shen, Haijun. "Optimal scheduling for satellite refueling in circular orbits." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/12331.

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15

Budianto, Irene Arianti. "A collaborative optimization approach to improve the design and deployment of satellite constellations." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/12384.

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16

Grungxu, Lungile Leonard. "Aspect of a hardware-in-the-loop integrated test system." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53292.

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Thesis (MScEng)--University of Stellenbosch, 2003.
ENGLISH ABSTRACT: A multiprocessor hardware-in-the-Ioop operating system was developed for the Integrated Test System (ITS) and is aimed at implementing the ITS as a space emulation vehicle. The thesis contains a study of satellite orbits, Kepler elements, geomagnetic fields and communication protocol between the processors. The system structure consists of an orbit generator, a core-operating system and is presented with a study of the satellite sensors. In implementing the orbit propagator, there was a need to pay special attention to the Halving algorithm, the Newton Raphson method and the True Solution. These algorithms were used to calculate the true anomaly angle as a function of eccentric anomaly. The communications protocol was tested and all the errors, with their solutions, have been discussed. A concept of a geomagnetic field emulator has also been included in the hardware-in-theloop operating system. The evaluation of those aspects of the system and the conclusion are presented together with recommendations.
AFRIKAANSE OPSOMMING: 'n multiprosesseerder Hardeware in die lus bedryfstelsel is ontwikkel vir 'n Geintegreerde Toets Stelsel (ITS) en poog om die ITS te implementeer as 'n ruimte emulasie stelsel. Die tesis behels die studie van sateliet wentelbane, Kepler wentelbaan elemente, geomagnetiese velde en kommunikasie protokolle tussen die prosesseerders. Die stelsel struktuur betaal uit 'n wentelbaan propageerder, 'n kern bedryfstelsel en 'n studie van satelliet instrumentasie. As 'n deel van die implementering van die wentelbaan propageerder is die halveer algoritme, Newton-Raphson algoritme en die ware oplossing as numeriese oplossings ondersoek. Die kommunikasie protokol is getoets en foute ondersoek en word bespreek. 'n konsep vir 'n Geomagnetiese veld emulasie word die hardeware in die lus stelsel ingesluit. Die stelsel word ge-ewalueer en die gevolgtrekkings en aanbevelings gemaak.

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17

Didier, Christopher J. "A commercial architecture for satellite imagery." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Sep%5FDidier.pdf.

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Thesis (M.S. in Space Systems Operations)--Naval Postgraduate School, September 2006.
Thesis Advisor(s): Richard C. Olsen, Alan D. Scott. "September 2006." Includes bibliographical references (p. 85-87). Also available in print.

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18

Kim, Jeongrae. "Simulation study of a low-low satellite-to-satellite tracking mission /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.

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19

Seybold, Calina Catherine. "Third body short period terms in analytic orbit prediction /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.

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20

King, Jeffery T. "A framework for designing optimal spacecraft formations." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FKing.pdf.

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Thesis (M.S. in Astronautical Engineering)--Naval Postgraduate School, September 2002.
Thesis advisor(s): I. Michael Ross, Fariba Fahroo. Includes bibliographical references (p. 73-75). Also available online.

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21

Salazar, Kardozo Alexandros. "A High-Level Framework for the Autonomous Refueling of Satellite Constellations." Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14534.

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Satellite constellations are an increasingly attractive option for many commercial and military applications. They provide a robust and distributed method of accomplishing the goals of expensive monolithic satellites. Among the many challenges that satellite constellations engender (challenges in control, coordination, disposal, and other areas), refueling is of particular interest because of the many methods one can use to refuel a constellation and the lifetime implications on the satellites. The present work presents a methodology for carrying out peer-to-peer refueling maneuvers within a constellation. Peer-to-peer (P2P) refueling can be of great value both in cases where a satellite unexpectedly consumes more fuel than it was alloted, and as part of a mixed refueling strategy that will include an outside tanker bringing fuel to the constellation. Without considering mixed-refueling, we formulate the peer-to-peer refueling problem as an assignment problem that seeks to guarantee that all satellites will have the fuel they need to be functional until the next refueling, while concurrently minimizing the cost in fuel that the refueling maneuvers entail. The assignment problem is then solved via auctions, which, by virtue of their distributed nature, can easily and effectively be implemented on a constellation without jeopardizing any robustness properties. Taking as a given that the P2P assignment problem has been solved, and that it has produced some matching among fuel deficient and fuel sufficient satellites, we then seek to sequence those prescribed maneuvers in the most effective manner. The idea is that while a constellation can be expected to have some redundancy, enough satellites leaving their assigned orbital slots will eventually make it impossible for the constellation to function. To tackle this problem, we define a wide class of operability conditions, and present three algorithms that intelligently schedule the maneuvers. We then briefly show how combining the matching and scheduling problems yields a complete methodology for organizing P2P satellite refueling operations.

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22

[UNESP], Santos Nadjara dos. "Pertubações orbitais devidas a maré terrestre." Universidade Estadual Paulista (UNESP), 2002. http://hdl.handle.net/11449/89857.

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Made available in DSpace on 2014-06-11T19:24:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2002Bitstream added on 2014-06-13T20:51:43Z : No. of bitstreams: 1 santos_n_me_guara.pdf: 418632 bytes, checksum: 4f860ab8b61150a88cbfa52adf66369f (MD5)
Aplicações recentes de satélites artificiais, principalmente aquelas com finalidades geodinâmicas e altimétricas, requerem órbitas determinadas com bastante precisão. Em particular as marés terrestres alteram o geopotencial, causando perturbações adicionais no movimento do satélite. Tais perturbações, apesar de pequenas, têm sido detectadas. O presente trabalho trata de perturbações de órbitas de satélites artificiais devidas às marés terrestres. Ênfase é dada aos termos seculares e de longo período. O potencial foi desenvolvido em termos dos elementos orbitais e substituídos nas equações planetárias de Lagrange. Soluções analíticas estão apresentadas para casos particulares considerando os números de Love constantes. Um programa foi elaborado, e colocado a disposição do usuário, permitindo calcular, para um dado satélite, a amplitude e o período dos termos perturbadores mais significativos.
Recent applications of artificial satellites, mainly those of geodynamics and altimetric purposes, requires high precise orbit determination. Particularly, Earth tides change the geopotencial causing additional perturbation in the satellite orbital motion. Inspite of being very small such perturbations, has been detected. The present work concerns about orbit perturbations of artificial satellites due do terrestrial tides. Treatment of secular and long period terms is emphasized. The potencial was developed in terms of the orbital elements and substituted in the Lagrange equations. Analytical solutions are presented for particular cases considering the Love’s number as constant. A computer enabling to compute, for a given satellite, the amplitude and period of the more significant disturbing terms, was constructed and it is, at the disposal for users.

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23

Lakshmanan, Prem Kumar. "A near optimum strategy for semipassive attitude control of large communications satellites." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25107.

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Effectiveness of solar radiation pressure in the three-axis attitude control of present day and next generation of large communications satellites is investigated. A simple two-flap configuration is used with optimization of the direction of the applied control moment rather than the magnitude of the weak solar radiation pressure. Simulations were carried out in the presence of varying orbital eccentricity and inclination, solar aspect angle and controller dynamics parameters. Time histories of librational response against orbital position are presented for controlled and uncontrolled conditions. The results suggest the semipassive controller to be quite effective over a wide range of system parameters and it can meet the exacting pointing accuracy demanded by large communications satellites.
Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate

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24

Remaklus, Perry Willmann. "Data acquisition and control system for the OLYMPUS propagation experiments." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10222009-125144/.

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Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991.
Seven folded leaves of schematic diagrams. Vita. Abstract. Includes bibliographical references (leaves 98-99). Also available via the Internet.

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25

Hu, Yurong. "Datagram routing for low earth orbit satellite networks." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B23273215.

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26

Herbert, Eric W. "NPSAT1 magnetic attitude control system algorithm verification, validation, and air-bearing tests." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Sep%5FHerbert.pdf.

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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, Sept. 2004.
Thesis advisor(s): Barry Leonard, Xiaoping Yun. Includes bibliographical references (p. 185-186). Also available online.

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27

Schoonwinkel, Johannes. "Attitude determination and control system of a nanosatellite." Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/708.

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28

Dutta, Atri. "Optimal cooperative and non-cooperative peer-to-peer maneuvers for refueling satellites in circular constellations." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28082.

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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

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29

Borgsmiller, Scott A. "Effects of atmospheric scintillation in K[a]-band satellite communications." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/14982.

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30

Alouini, Mohamed-Slim. "Impact of the atmosphere on K [subscript a]-Band satellite communication systems." Thesis, Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/15364.

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31

Marandi, Said Rashed. "On some aspects of dynamics, modelling, and attitude analysis of satellites." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/29019.

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The thesis identifies several limitations in the modelling and attitude stability analysis of two classes of spacecraft: rigid and flexible satellites. Attractive methods are proposed which promise to have far reaching consequences in spacecraft dynamics. These alternatives, developed based on techniques of differential equations, classical mechanics, and differential topology, are indicated below. (a) An Alternate Transition from the Lagrangian of a Satellite to Equations of Motion The classical procedure requires the Lagrangian to be expressed in terms of the corresponding generalized coordinates of the problem. This requirement significantly complicates the derivation of the equations of motion through an introduction of a set of librational generalized coordinates, which is strictly not a part of the dynamical system. Using the Lagrangian in the natural variables (angular velocity, direction cosines, and vibrational coordinates), one develops a procedure for derivation of equations of motion without an a priori choice of rotational generalized coordinates. For the case of a satellite with two flexible plate-type appendages, for example, the approach reduced the formulation time to one-third. (b) Synthesis and Depiction of Rotational Motion of Satellites and Robots The rotational coordinates in use for numerical prediction of orientation of a satellite are either singular or redundant. Furthermore, they lack a convenient visual interpretation. A new set of coordinates is proposed and an associated representation is developed which avoids these limitations. The procedure is applied to represent and integrate numerically the librational response of the flexible satellite mentioned in (a). (c) Resolution of Attitude Stability of Delp Satellites The development here tackles a long outstanding problem in the area of attitude stability of satellites. The resolution of this problem through normalization of the Hamiltonian leads to a better appreciation of stability associated with the class of gravity gradient structures such as the proposed Space Station.
Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate

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32

Moorthy, Ananthalakshmy Krishna. "EXTENDED ORBITAL FLIGHT OF A CUBESAT IN THE LOWER THERMOSPHERE WITH ACTIVE ATTITUDE CONTROL." Digital WPI, 2019. https://digitalcommons.wpi.edu/etd-dissertations/558.

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A wide variety of scientifically interesting missions could be enabled by orbital flight altitudes of 150 – 250 km. For the present work, this range of altitudes is defined as extremely Low Earth Orbit (eLEO). The use of low-cost nanosatellites (mass < 10 kg) has reduced the cost barrier to orbital flight over the last decade and the present study investigates the feasibility of using primarily commercial, off-the-shelf (COTS) hardware to build a nanosat specifically to allow extended mission times in eLEO. CubeSats flying in the lower thermosphere have the potential to enable close monitoring of the Earth’s surface for scientific, commercial, and defense-related missions. The results of this research show that the proper selection of primary and attitude control thrusters combined with precise control techniques result in significant extension of the orbital life of a CubeSat in eLEO, thus allowing detailed explorations of the atmosphere. In this study, the orbit maintenance controller is designed to maintain a mission-averaged, mean altitude of 244 km. An estimate is made of the primary disturbance torque due to aerodynamic drag using a high-fidelity calculation of the rarefied gas drag based on a Direct Simulation, Monte-Carlo simulation. The primary propulsion system consists of a pair of electrospray thrusters providing a combined thrust of 0.12 mN at 1 W. Results of a trade study to select the best attitude control option indicate pulsed plasma thrusters operating at 1 W are preferable to reaction wheels or mangetorquers at the selected altitude. An extended Kalman filter is used for orbital position and spacecraft attitude estimations. The attitude determination system consists of sun sensors, magnetometers, gyroscopes serving as attitude sensors. The mission consists of two phases. In Phase I, a 4U CubeSat is deployed from a 414 km orbit and uses the primary propulsion system to deorbit to an initial altitude within the targeted range of 244 +/- 10 km. Phase I lasts 12.73 days with the propulsion system consuming 5.6 g of propellant to deliver a ∆V of 28.12 m/s. In Phase II the mission is maintained until the remaining 25.2 g of propellant is consumed. Phase II lasts for 30.27 days, corresponding to a ∆V of 57.22 m/s with a mean altitude of 244 km. The mean altitude for an individual orbit over the entire mission was found to vary from a maximum of 252 km to a minimum of 236 km. Using this approach, a primary mission life of 30.27 days could be achieved, compared with 3.1 days without primary propulsion.

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33

Pitre, J. D. Gilbert Carleton University Dissertation Engineering Mechanical and Aerospace. "Spinning mode algorithms for the satellite attitude sensor." Ottawa, 1999.

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34

胡玉蓉 and Yurong Hu. "Datagram routing for low earth orbit satellite networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31224441.

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35

Polaha, James Henry. "An analysis of low-earth-orbit-satellite communication systems." Thesis, Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/74533.

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There is an ever increasing need for low-cost communication systems in the world. One such system, low-earth-orbit satellites, can provide store-and-forward, as opposed to real time, communication for many earth stations. The advantages and disadvantages of such a system is presented. Material covering protocols and communications architectures is elaborated upon for the use of amateur radio communications. Doppler shift and its effect on satellites in low-earth-orbit is examined. Efficiency and throughput of the Amateur X.25 Protocol will be explored. The last chapter entails the analysis of the PACSAT experiment.
Master of Science

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36

Pradhan, Hrishi Bahadur. "Potential for identifying changes in land cover in Nepal using satellite imagery /." This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-04272010-020133/.

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37

Young, James Jamy. "A value proposition for lunar architectures utilizing on-orbit propellant refueling." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28149.

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Thesis (M. S.)--Aerospace Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Wilhite, Alan; Committee Member: Bishop, Carlee; Committee Member: Chytka, Trina; Committee Member: Schrage, Daniel; Committee Member: Stanley, Douglas.

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Haeffelin, Martial. "A numerical study of equivalence in scanning thermistor bolometer radiometers for earth radiation budget applications." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-12302008-063832/.

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Gonsalvez, David J. A. "On orbital allotments for geostationary satellites /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487322984313812.

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Byun, Sung Hun. "Satellite orbit determination using GPS carrier phase in pure kinematic mode /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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Score, Robert H. "An examination of XM satellite subscriber's perceptions of satellite radio compared to traditional AM/FM radio." Instructions for remote access. Click here to access this electronic resource. Access available to Kutztown University faculty, staff, and students only, 2002. http://www.kutztown.edu/library/services/remote_access.asp.

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Thesis (M.S.)--Kutztown University of Pennsylvania, 2002.
Source: Masters Abstracts International, Volume: 45-06, page: 2720. Typescript. Abstract precedes thesis as preliminary leaves 1-2. Includes bibliographical references (leaves 34-35).

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Haidara, Fatim M. "Characterization of tropospheric scintillations on Earth-space paths in the Ku and Ka frequency bands using the results from the Virginia Tech OLYMPUS experiment." Diss., This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06062008-170624/.

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Kulick, Wayne J. "Development of a Control Moment Gyroscope controlled, three axis satellite simulator, with active balancing for the bifocal relay mirror initiative." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Dec%5FKulick.pdf.

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Van, Wyk John Foster. "Reusable software defined radio platform for micro-satellites." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/1346.

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Pearson, Kyle A., Leon Palafox, and Caitlin A. Griffith. "Searching for exoplanets using artificial intelligence." OXFORD UNIV PRESS, 2018. http://hdl.handle.net/10150/627143.

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In the last decade, over a million stars were monitored to detect transiting planets. Manual interpretation of potential exoplanet candidates is labour intensive and subject to human error, the results of which are difficult to quantify. Here we present a new method of detecting exoplanet candidates in large planetary search projects that, unlike current methods, uses a neural network. Neural networks, also called 'deep learning' or 'deep nets', are designed to give a computer perception into a specific problem by training it to recognize patterns. Unlike past transit detection algorithms, deep nets learn to recognize planet features instead of relying on hand-coded metrics that humans perceive as the most representative. Our convolutional neural network is capable of detecting Earth-like exoplanets in noisy time series data with a greater accuracy than a least-squares method. Deep nets are highly generalizable allowing data to be evaluated from different time series after interpolation without compromising performance. As validated by our deep net analysis of Kepler light curves, we detect periodic transits consistent with the true period without any model fitting. Our study indicates that machine learning will facilitate the characterization of exoplanets in future analysis of large astronomy data sets.

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Gremont, Boris Christian. "Fade countermeasure modelling for Ka band digital satellite links." Thesis, Coventry University, 1997. http://curve.coventry.ac.uk/open/items/d85e8a85-635c-d024-3737-d1205f235596/1.

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This thesis investigates the modelling of fade countermeasures (FCMs) for the design of geostationary Ka band digital satellite communication systems. The analysis focuses on a typical low-power low-rate very small aperture terminal application using adaptive forward error correction as a way of counteracting the high level of detected dynamic atmospheric fading. The management and performance of such systems is conditioned greatly by the ability of practical controllers at detecting the actual level of total signal attenuation. At 20 or 30 GHz, rain attenuation and tropospheric scintillation are the two major propagation effects of interest. Part of the solution relies on the consideration and integration of their random and dynamic nature in the design process. The finite response time of practical countermeasure systems is a source of performance degradation which can be minimised by the implementation of predictive control strategies. This is the focal point of this thesis. A novel on-line short-term predictor matched to the Ka band fading process is proposed. While the rain attenuation component is efficiently predicted, tropospheric scintillation is the source of the estimation error. To take this into account, a statistical model, based on an extension of the global fading model for rain and scintillation, is then developed so that long term performance of predictive countermeasures can be drawn. Two possible ways to compensate for scintillation-induced prediction errors, namely the fixed and variable detection margin approaches, are proposed, analysed and then compared. This is achieved by calculating the FCM utilisation factor, as well as the throughput and bit error rate performance of a typical Ka band system in the presence of dynamic fading within the context of predictive fade countermeasure control operations. In the last part of this thesis, the inclusion of instantaneous frequency scaling in the design of efficient FCM control schemes is investigated. This is applicable to systems using fade detection at a base frequency. In particular, a new statistical model, accounting for the impact of the stochastic temporal variations of rain drop size distribution on rain attenuation, is presented. This thesis further confirms that countermeasure systems are technologically viable. The consideration of more specific design problems does not change the overall validity of this statement. In this thesis, it is shown that a predictive FCM technique, based on readily available punctured convolutional codes, with their relatively modest coding gain, is sufficient to provide high link availability and user data throughput on a low-power low-rate in-bound VSAT link.

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Mendy, Paul B. "Multiple satellite trajectory optimization /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Dec%5FMendy.pdf.

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Thesis (M.S. in Astronautical Engineering and Astronautical Engineer)--Naval Postgraduate School, December 2004.
Thesis advisor(s): I. Michael Ross, D. A. Danielson. Includes bibliographical references (p. 93-94). Also available online.

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Fernández-Briseño, Raúl. "Legal aspects of telecommunication satellites operation and financing." Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=19641.

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Over the last years the demand for satellite communication services has been increased. Global and domestic regulatory developments and support, as well as the emerge of new services, have facilitated launcMng capabilities and reduced the costs of manufacturing, launching and operating the satellites. Financing the telecommunication satellite systems is one of the most relevant issues that prospective satellite operators face on these days. Mstitutional lenders require adequate legal advise in order to properly instrument multimillion transactions where securitization is not enough clear and risks are extremely Mgh. TMs work analyzes the most important sources of financing of telecommunication satellites and the most adequate legal structures and methods based in legislation, legal cases, jurisprudence, doctrine, and legal practice.

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Dlamini, Zamokwakhe P. (Zamokwakhe Peacemaker). "Attitude sensor and actuator interfacing for micro-satellites." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52715.

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Thesis (MScEng)--University of Stellenbosch, 2002.
ENGLISH ABSTRACT: The purpose of this thesis was to design and test the interfaces of sensors and actuators. In the complete Attitude Determination and Control System CADCS) the Interface Control Processor (ICP) must be interfaced to various sensors and torquers. The testing of interfaces involves the simulation of sensors and actuators and also two of the Attitude Control Processor's functions, i.e. sending actuator commands and receiving sensor data. The tested interfaces are for two actuators and three sensors. Both analog and digital sensors and actuators are interfaced i.e. reaction wheels, magnetorquers, magnetometer and horizon /fine sun sensor. The simulated sensors and actuators are to be employed on three axis controlled, low earth o~biting micro-satellites. To test the interfaces, a test circuit was developed and the design is presented. Finally the software to facilitate the testing was developed and is also presented with the analysis based on protocol implementation and data rates.
AFRIKAANSE OPSOMMING: Die doel van hierdie tesis was om sensor en aktueerder koppelvlakke te ontwerp en te toets. In die volledige Attitude Determination and Control System CADCS) moet die Interface Control Processor CICP) aan verskeie sensore en torquers gekoppel word. Die toets van koppelvlakke behels die simulasie van sensore en aktueerders en ook twee van die Attitude Control Processor (ACP) se funksies, naamlik die stuur van aktueerder bevele en die ontvang van sensor data. Die koppelvlakke vir twee aktueerders en drie sen sore is getoets. Beide analoog en digitale sensore en aktueerders is gekoppel, naamlik die reaksiewiele, magneetspoele, magnetometer en horison I fyn son sensor. Die gesimuleerde sensore en aktueerders sal gebruik word op drie-as beheerde, lae aardbaan mikrosatelliete. Om die koppelvlakke te toets is 'n stroombaan ontwikkel waarvan die ontwerp hier aangebied word. Sagteware om die toetse te fasiliteer is ontwikkel en word ook hier aangebied tesame met . analises gebaseer op protokol implementering en data tempo's.

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Maillard, Adrien. "Flexible Scheduling for Agile Earth Observing Satellites." Thesis, Toulouse, ISAE, 2015. http://www.theses.fr/2015ESAE0024/document.

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Les satellites d’observation de la Terre sont des senseurs qui acquièrent des données, les compressent et les mémorisent à bord, puis les vident vers le sol. Des incertitudes rendent la planification des activités au sol de plus en plus discutable car la planification est alors pessimiste et les plans largement sous-optimaux. Cette thèse détaille la conception d'une planification mixte qui permet de profiter de la réalisation des paramètres incertains à bord tout en préservant la prévisibilité de l'exécution pour les opérateurs au sol. Notre première contribution concerne le problème de planification des vidages. Un mécanisme de planification flexible a été conçu dans lequel seules les acquisitions de haute priorité sont planifiées de manière pessimiste. A bord, un algorithme adapte le plan en fonction des volumes réels, en s'assurant que le vidage des acquisitions de haute priorité est toujours garanti, et insère des nouveaux vidages si possible. Notre deuxième contribution concerne le problème de planification des acquisitions. Au sol, des contraintes contribuent à éliminer du plan de nombreuses acquisitions qui auraient pu être réalisées car les niveaux de ressources à bord sont souvent plus hauts que ceux prévus par ces contraintes. Dans un nouveau mécanisme de décision, le sol produit des plans conditionnels dans lesquels la réalisation des acquisitions de basse priorité est conditionnée par des niveaux d'énergie requis. Comparées à d'autres mécanismes de planification, ces deux approches flexibles permettent d'éviter le gaspillage des ressources et de réaliser plus d'acquisitions et de vidages tout en conservant de la prévisibilité
Earth-observation satellites are space sensors which acquire data, compress and record it on board, and then download it to the ground. Some uncertainties make planning and scheduling satellite activities offline on the ground more and more arguable as worst-case assumptions are made about uncertain parameters and plans are suboptimal. This dissertation details our efforts at designing a flexible decision-making scheme that allows to profit from the realization of uncertain parameters on board while keeping a fair level of predictability on the ground. Our first contribution concerns the data download problem. A flexible decision-making mechanism has been designed where only high-priority acquisition downloads are scheduled with worst-case assumptions. Other acquisition downloads are scheduled with expected parameters and conditioned by resource availability. The plan is then adapted on board. Our second contribution concerns the acquisition planning problem. A lot of acquisitions that could have been done are eliminated when planning because of worst-case assumptions. In a new decision-making scheme, these high-level constraints are removed for low-priority acquisitions. Observation plans produced on the ground are conditional plans involving conditions for triggering low-priority acquisitions. Compared with pure ground and pure onboard methods, these two approaches avoid wastage of resource and allow more acquisitions to be executed and downloaded to the ground while keeping a fair level of predictability on the ground

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