Thesis (Ph. D.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (May 25, 2006) Vita. Includes bibliographical references.

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M.Sc. (Geography) / The aim of this research is to determine if, by means of Landsat MSS digital data, urban land use classes can be identified and separated, and if changes in land use (urban sprawl) can be detected, over a period of time. Regional authorities function at inter-municipal scale. In order for these instittitions to perform these functions, they need to have access to standardized data (standardized in scale, time and interpretation) in order to obtain a global view of the total area under their authority. Remotely sensed digital data have the potential to fulfil these needs. A secondary objective will then also be to make an evaluation of the various applications of the results to the relevant authorities.

Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: The aim of the thesis is the design of an economical do - it - yourself ground station for school pupils to communicate with SUNSAT 1. The ground station should also be more economical than a hand - held transceiver radio. The do - it - yourself requirement is there to arouse an interest in electronics, radio frequency electronics and satellite communications in school pupils. A system-level design was done for a ground station consisting of modules which may be bought individually as do - it - yourself kits to eventually produce a full set. The modules are a VHF receiver, a VHF transmitter, a UHF down converter and a modem. Each module has functions which aid in the process of communications (data as well as voice) between the satellite and the ground station. A VHF receiver was designed and implemented to be capable of receiving RF signals from SUNSAT 1. A crystal controlled oscillator was designed that oscillates with a frequency tolerance of less than or equal to ± 0.003 % when aligned without the necessary IlF equipment. An economical Broadband Signal Generator was implemented with a 74ACT14 logic IC, which may be used to align the receiver. The higher harmonics of a square wave with a fundamental frequency of 4 kHz are used as a RF source. A sound card was utilised as a modem to receive 1200 baud AFSK (AX.25 protocol) data and the software was also used to display the data on PC. The data was transmitted from another ground station / AFRIKAANSE OPSOMMING: Die doel van die tesis is die ontwerp van 'n ekonomiese doen - dit - self - grondstasie vir skoolkinders om met SUNSAT I te kan komunikeer. Die grondstasie moet ook meer ekonomies wees as 'n handstelradio. Die doel van die doen - dit - self - beginsel is om die belangstelling in elektronika, RF elektronika and satelliete by skoolkinders aan te moedig. 'n Stelsel ontwerp van 'n grondstasie is gedoen wat bestaan uit modules wat afsonderlik as doen - dit - self - modules aangeskaf kan word om so tot 'n totale grondstasie op te bou. Die modules is die "VHF" - ontvanger, "VHF" - sender, UHF - afmenger en 'n modem. Elke module verskaf funksies wat bydra om met SUNSAT I te kan kornmunikeer. 'n VHF - ontvanger wat in staat is om RF - seine vanaf SUNSAT I te ontvang is ontwerp en gebou. 'n Kristal b heerde ossillator is ontwerp met 'n frekwensie toleransie van kleiner en gelyk aan ± 0.003 % wanneer dit ingestem word sender die nodige RF toerusting. 'n Ekonomiese wyeband - seingenerator is gemplementeer met 'n 74ACT14 logiese vlokkie om as 'n RF - bron gebruik te word om die ontvanger in te stel. Die boonste (hoer) harmoniek van die 4 kHz vierkantsgolf word as 'n "RF bron" gebruik. 'n Klankkaart is suksesvol gebruik as 'n modem om 1200 baud AFSK data (AX.25 protokol) te ontvang en die data met die nodige sagteware op 'n skerm te vertoon. Data is uitgcstuur vanaf 'n ander grondstasie.

Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: This thesis describes various software technologies implemented, or specifically developed, for the SUNSAT micro-satellite mission. With the discussion centered on the Mission Operations System functions of Data Handling and Mission Control, particular emphasis is placed on data processing aspects such as the deployed database schema, and the data communications mechanisms implemented as part of the communications protocol stack. Both the groundsystem architecture and the Flight Software are discussed, their constituent components are analysed, and recommendations are made for improvement. Finally, a Unified Information Model for the design and operation of future, integrated satellite groundsystems is proposed, with suitable implementation technologies being identified and introduced. / AFRIKAANSE OPSOMMING: Hierdie tesis beskryf die sagteware tegnologieë wat qeirnpternenteer. of spesifiek ontwerp is vir die SUNSAT mikro-satelliet missie, Met die bespreking gefokus op die Missie Operasionele Stelsel funksies van Data Hantering en Missie Beheer, word daar veral klem gelê op data prosesserings aspekte, soos byvoorbeeld die databasis skema wat ontplooi is, asook die data kommunikasie meganismes wat qeimplernenteer is as deel van die kommunikasie protokol stapel. Beide die grondstelsel argitektuur en die Vlugsagteware word bespreek, hulonderskeie komponente word geanaliseer, en aanbevelings ter verbetering word gemaak, Laastens word daar 'n Verenigde Informasie Model voorgestel vir die ontwerp en operasionele werking van 'n toekomstige, qeinteqreerde satelliet grondstelsel. Geskikte tegnologieë vir die implementasie hiervan word ook qeidentifiseer en voorgelê,

Thesis (MScEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: The primary payload of the University of Stellenbosch's micro-satellite, SUNSAT I, was a high quality imager, capable of taking stereoscopic images of the surface of the earth. Although the orbit of SUNSAT I will have the satellite pass over the whole earth, contact via the SUNSAT I ground station at the University will only be made for 3% of each day. To be able to photograph any part of the earth onboard memory was provided on the satellite to store the image until it can be downloaded to the ground station. A high speed downlink was also added to the satellite to be able to download a complete image from the onboard memory in one pass and also to take realtime pictures as the satellite passes over the ground station. At that stage there was no way to capture the data at the ground station. A high speed digital data capture mechanism was needed. The thesis discusses the development of a high speed capture card. Due to the high speeds needed it provided an excellent opportunity to develop the card using the PCI bus, the first design to do so at the University, as an interface with a computer. A prototype card was developed first to do proof of concept. It is shown that the prototype card fulfilled the functional requirements and it was also used to capture the first image from the complete satellite during the final tests before launch. Finally a production card for use in the ground station was designed and assembled. / AFRIKAANSE OPSOMMING: Die hoof loonvrag van die Universtieit van Stellenbosch se eerste mikrosatelliet, SUNSAT I, is "n hoë kwaliteit kamera wat stereoskopiese fotos van die oppervlak van die aarde kan neem. Alhoewel die satelliet oor die hele oppervlakte van die aarde gaan beweeg, is dit vir slegs 3% van die dag sigbaar vanaf die grondstasie by die Universiteit van Stellenbosch. Om 'n foto van enige plek op aarde te kan neem is daar aanboord geheue op die satelliet geplaas om die foto te stoor totdat dit by die grondsatsie afgelaai kan word. "n Hoë spoed skakel is ook daargestelom die data in die geheue van die satelliet in een verbyvlug te kan aflaai. Dit stel die satelliet ook in staat om intydse fotos gedurende In verbyvlug van die satelliet te kan neem. Op daardie stadium het daar nog nie "n manier bestaan om die hoë spoed data vas te lê nie. In Meganisme om die hoë spoed digitale data te vang was nodig. Hierdie tesis bespreek die ontwikkeling van so In data vang kaart. Weens die hoë snelhede wat benodig word, het die PCI bus die ideale oplossing gebied om die data teen "n hoë spoed op In persoonlike rekenaar te stoor. Dit was ook die eerste ontwerp aan die Universiteit wat van die PCI bus gebruik gemaak het. In die eerste instansie is In prototipe ontwikkel om te bewys dat dit wel moontlik is om die data teen die benodigde tempo te kan stoor. Daar word gewys dat die prototipe aan die behoefte voldoen en dit is ook gebruik om die eerste beeld vanaf die volledige satelliet te vang voordat dit gelanseer is. In die tweede instansie word In produksiekaart ontwikkel en aanmekaar gesit.

Ce travail de thèse consiste au développement de méthodes statistiques pour détecter des com- portements anormaux dans les données fonctionnelles que produit le satellite tout au long de sa vie. Un premier travail a été de comprendre comment mettre en évidence les anomalies grâce à des projections sur des bases de fonctions. En complément de cette revue des projections, nous avons appliqué plusieurs méthodes de détection d’anomalies, telles que la One-Class SVM et le Local Outlier Factor (LOF). En plus de ces deux méthodes, nous avons développé notre propre méthode pour prendre en compte la saisonnalité des courbes que nous considérons. En se basant sur cette étude, nous avons développé une nouvelle procédure pour sélectionner automatiquement les coefficients les plus intéressants pour la détection d’anomalies dans un cadre semi-supervisé. Notre méthode est une procédure de tests multiples où nous appliquons un test à deux échantillons à tous les niveaux de coefficients. Nous nous sommes également intéressés aux covariances des télémesures entre elles pour la détection d’anomalies. Pour cela, nous cherchons à comparer les covariances entre un groupe de télémesures pour deux journées, ou périodes consécutives. Nous avons appliqué trois tests sta- tistiques ayant des angles d’approche différents. Nous avons également développé dans ce but un nouveau test asymptotique. Outre la démonstration de la convergence de notre test, nous démontrons par des exemples que ce test est dans la pratique le plus puissant sur les données dont nous disposons. Dans cette thèse, nous avons abordé plusieurs aspects de la détection d’anomalies dans les données fonctionnelles issues des satellites. Pour chacune des méthodes, nous avons pu détecter toutes les anomalies, améliorant sensiblement le taux de fausses alarmes. / In this PhD, we have developed statistical methods to detect abnormal events in all the functional data produced by the satellite all through its lifecycle. The data we are dealing with come from two main phases in the satellite’s life, telemetries and test data. A first work on this thesis was to understand how to highlight the outliers thanks to projections onto functional bases. On these projections, we have also applied several outlier detection methods, such as the One-Class SVM, the Local Outlier Factor (LOF). In addition to these two methods, we have developed our own outlier detection method, by taking into account the seasonality of the data we consider. Based on this study, we have developed an original procedure to select automatically the most interesting coefficients in a semi-supervised framework for the outlier detection, from a given projection. Our method is a multiple testing procedure where we apply the two sample-test to all the levels of coefficients.We have also chosen to analyze the covariance matrices representing the covariance of the te- lemetries between themselves for the outlier detection in multivariate data. In this purpose, we are comparing the covariance of a cluster of several telemetries deriving from two consecutive days, or consecutive orbit periods. We have applied three statistical tests targeting this same issue with different approaches. We have also developed an original asymptotic test, inspired by both first tests. In addition to the proof of the convergence of this test, we demonstrate thanks to examples that this new test is the most powerful. In this PhD, we have tackled several aspects of the anomaly detection in the functional data deriving from satellites. For each of these methods, we have detected all the major anomalies, improving significantly the false discovery rate.