Thèses sur le sujet « Satellite Integration »

The satellite avionics platform has been developed in cooperation with Airbus and is called „Future Low-cost Platform“ (FLP). It is based on an Onboard Computer (OBC) with redundant processor boards based on SPARC V8 microchips of type Cobham Aeroflex UT699. At the University of Stuttgart a test bench with a real hardware OBC and a fully simulated satellite is available for testing real flight scenarios with the Onboard Software (OBSW) running on representative hardware. The test bench as later the real flying satellite "Flying Laptop" – is commanded from a real Ground Control Centre (GCC). The main challenges in the FLP project were - Onboard computer design, - Software design and - Interfaces between platform and payloads In the course of industrialization of this FLP platform technology for later use in satellite constellations, Airbus has started to set up an in-house test bench where all the technologies shall be developed. The initial plan is to get first core elements of the FLP OBSW ported to the new dual-core processor and the new Space Wire(SpW) routing network. The plan also has an inclusion of new Mission Control Software with which one can command the OBC. The new OBC has a dual core processor Cobham Gaisler GR712 and hence, all the payload and related functionality are to be implemented only in a second core which involves a lot of low-level task distribution. The consequent SpW router network application and dual-core platform/payload OBSW sharing are entirely new in the field of satellite engineering.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada
PC technology has progressed to the point that it can very effectively support commercial geostationary spacecraft design, manufacture, test, launch, ground station, and on-orbit mission control activities. Many of the manufacturers that provide VME spacecraft test hardware and software are now providing the same functions and performance for the PC. A PC workstation equipped with single and multiple Pentium processors and Windows NT software can support single and multiple uplinks/downlinks and provide client/server capabilities that perform traditional UNIX client/server operations. Such a PC workstation can provide the functionality, features, and performance necessary for commercial spacecraft board-level test, unit-level test, subsystem-level test, spacecraft bus and payload integration, and ground station monitoring and control, as well as on-orbit mission control activities.

This paper deals with study of inertial navigation, global navigation satellite system, and their fusion into the one navigation solution. The first part of the work is to calculate the trajectory from accelerometers and gyroscopes measurements. Navigation equations calculate rotation with quaternions and remove gravity sensed by accelerometers. The equation’s output is in earth centred fixed navigation frame. Then, inertial navigation errors are discussed and focused to the bias correction. Theory about INS/GNSS inte- gration compares different integration architecture. The Kalman filter is used to obtain navigation solution for attitude, velocity and position with advantages of both systems.

The recent technological advances in the satellite domain such as the use of High Throughput Satellites (HTS) with throughput rates that are magnitudes higher than with previous ones, or the use of large non- Geostationary Earth Orbit (GEO) satellites constellations, etc, are reducing the price per bit and enhancing the Quality of Service (QoS) metrics such as latency, etc., changing the way that the capacity is being brought to the market and making it more attractive for other services such as satellite broadband communications. These new capabilities coupled with the advantages offered by satellite communications such as the unique wide-scale geographical coverage, inherent broadcast/multicast capabilities and highly reliable connectivity, anticipate new opportunities for the integration of the satellite component into the 5G ecosystem. One of the most compelling scenarios is mobile backhauling, where satellite capacity can be used to complement the terrestrial backhauling infrastructure, not only in hard to reach areas, but also for more efficient traffic delivery to Radio Access Network (RAN) nodes, increased resiliency and better support for fast, temporary cell deployments and moving cells. In this context, this thesis work focuses on achieving better satellite-terrestrial backhaul network integration through the development of Traffic Engineering (TE) strategies to manage in a better way the dynamically steerable satellite provisioned capacity. To do this, this thesis work first takes the steps in the definition of an architectural framework that enables a better satellite-terrestrial mobile backhaul network integration, managing the satellite capacity as a constituent part of a Software Defined Networking (SDN) -based TE for mobile backhaul network. Under this basis, this thesis work first proposes and assesses a model for the analysis of capacity and traffic management strategies for hybrid satellite-terrestrial mobile backhauling networks that rely on SDN for fine-grained traffic steering. The performance analysis is carried out in terms of capacity gains that can be achieved when the satellite backhaul capacity is used for traffic overflow, taking into account the placement of the satellite capacity at different traffic aggregation levels and considering a spatial correlation of the traffic demand. Later, the thesis work presents the development of SDN-based TE strategies and algorithms that exploits the dynamically steerable satellite capacity provisioned for resilience purposes to better utilize the satellite capacity by maximizing the network utility under both failure and non-failure conditions in some terrestrial links, under the consideration of elastic, inelastic and unicast and multicast traffic. The performance analysis is carried out in terms of global network utility, fairness and connexion rejection rates compared to non SDN-based TE applications. Finally, sustained in the defined architectural framework designs, the thesis work presents an experimental Proof of Concept (PoC) and validation of a satellite-terrestrial backhaul links integration solution that builts upon SDN technologies for the realization of End-to-End (E2E) TE applications in mobile backhauling networks with a satellite component, assessing the feasibility of the proposed SDN-based integration solution under a practical laboratory setting that combines the use of commercial, experimentation-oriented and emulation equipment and software.
Los recientes avances tecnológicos en el dominio de los satélites, como el uso de satélites de alto rendimiento (HTS) con tasas de rendimiento que son magnitudes más altas que los anteriores, o el uso de grandes constelaciones de satélites de órbita no geoestacionaria (GEO), etc. están reduciendo el precio por bit y mejorando las métricas de Calidad de Servicio (QoS) como la latencia, etc., cambiando la forma en que la capacidad se está llevando al mercado, y haciéndola más atractiva para otros servicios como las comunicaciones de banda ancha por satélite. Estas nuevas capacidades, junto con las ventajas ofrecidas por las comunicaciones por satélite, como la cobertura geográfica a gran escala, las inherentes capacidades de difusión / multidifusión y la conectividad altamente confiable, anticipan nuevas oportunidades para la integración de la componente satelital al ecosistema 5G. Uno de los escenarios más atractivos es el backhauling móvil, donde la capacidad del satélite se puede usar para complementar la infraestructura de backhauling terrestre, no solo en áreas de difícil acceso, sino también para la entrega de tráfico de manera más eficiente a los nodos de la Red de Acceso (RAN), una mayor resiliencia y mejor soporte para implementaciones rápidas y temporales de células, así como células en movimiento. En este contexto, este trabajo de tesis se centra en lograr una mejor integración de la red híbrida de backhaul satélital-terrestre, a través del desarrollo de estrategias de ingeniería de tráfico (TE) para gestionar de una mejor manera la capacidad dinámicamente orientable del satélite. Para hacer esto, este trabajo de tesis primero toma los pasos en la definición de un marco de arquitectura que permite una mejor integración de una red híbrida satelital-terrestre de backhaul móvil, gestionando la capacidad del satélite como parte constitutiva de un TE basado en Software Defined Networking (SDN). Bajo esta base, este trabajo de tesis primero propone y evalúa un modelo para el análisis de la capacidad y las estrategias de gestión del tráfico para redes híbridas satelital-terrestre de backhaul móvil basadas en SDN para la dirección de tráfico. El análisis de rendimiento se lleva a cabo en términos de aumento de capacidad que se puede lograr cuando la capacidad de la red de backhaul por satélite se utiliza para el desborde de tráfico, teniendo en cuenta la ubicación de la capacidad del satélite en diferentes niveles de agregación de tráfico y considerando una correlación espacial de la demanda de tráfico. Posteriormente, el trabajo de tesis presenta el desarrollo de estrategias y algoritmos de TE basados en SDN que explotan la capacidad dinámicamente orientable del satelite, provista con fines de resiliencia para utilizar de mejor manera la capacidad satelital al maximizar la utilidad de red en condiciones de falla y no falla en algunos enlaces terrestres, y bajo la consideración de tráfico elástico, inelástico y de unidifusión y multidifusión. El análisis de rendimiento se lleva a cabo en términos de tasas de rechazo, de utilidad, y equidad en comparación con las aplicaciones de TE no basadas en SDN. Finalmente, basado en la definición del diseño de marco de arquitectura, el trabajo de tesis presenta una Prueba de concepto (PoC) experimental y la validación de una solución de integración de enlaces de backhaul satelital-terrestre que se basa en las tecnologías SDN para la realización de aplicaciones de TE de extremo a extremo (E2E) en redes de backhaul móviles, evaluando la viabilidad de la solución propuesta de integración basada en SDN en un entorno práctico de laboratorio que combina el uso de equipos y software comerciales, orientados a la experimentación y emulación.

Thesis (Ph. D.) -- University of Maryland, College Park, 2009.
Thesis research directed by: Dept. of Geography. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

In order to better understand the geological boundary conditions for ongoing or past surface processes geologists face two important questions: 1) How can we gain additional knowledge about geological processes by analyzing digital elevation models (DEM) and satellite images and 2) Do these efforts present a viable approach for more efficient research. Here, we will present case studies at a variety of scales and levels of resolution to illustrate how we can substantially complement and enhance classical geological approaches with remote sensing techniques.

Commonly, satellite and DEM based studies are being used in a first step of assessing areas of geologic interest. While in the past the analysis of satellite imagery (e.g. Landsat TM) and aerial photographs was carried out to characterize the regional geologic characteristics, particularly structure and lithology, geologists have increasingly ventured into a process-oriented approach. This entails assessing structures and geomorphic features with a concept that includes active tectonics or tectonic activity on time scales relevant to humans. In addition, these efforts involve analyzing and quantifying the processes acting at the surface by integrating different remote sensing and topographic data (e.g. SRTM-DEM, SSM/I, GPS, Landsat 7 ETM, Aster, Ikonos…). A combined structural and geomorphic study in the hyperarid Atacama desert demonstrates the use of satellite and digital elevation data for assessing geological structures formed by long-term (millions of years) feedback mechanisms between erosion and crustal bending (Zeilinger et al., 2005). The medium-term change of landscapes during hundred thousands to millions years in a more humid setting is shown in an example from southern Chile. Based on an analysis of rivers/watersheds combined with landscapes parameterization by using digital elevation models, the geomorphic evolution and change in drainage pattern in the coastal Cordillera can be quantified and put into the context of seismotectonic segmentation of a tectonically active region. This has far-reaching implications for earthquake rupture scenarios and hazard mitigation (K. Rehak, see poster on IMAF Workshop). Two examples illustrate short-term processes on decadal, centennial and millennial time scales: One study uses orogen scale precipitation gradients derived from remotely sensed passive microwave data (Bookhagen et al., 2005a). They demonstrate how debris flows were triggered as a response of slopes to abnormally strong rainfall in the interior parts of the Himalaya during intensified monsoons. The area of the orogen that receives high amounts of precipitation during intensified monsoons also constitutes numerous landslide deposits of up to 1km³ volume that were generated during intensified monsoon phase at about 27 and 9 ka (Bookhagen et al., 2005b). Another project in the Swiss Alps compared sets of aerial photographs recorded in different years. By calculating high resolution surfaces the mass transport in a landslide could be reconstructed (M. Schwab, Universität Bern).

All these examples, although representing only a short and limited selection of projects using remote sense data in geology, have as a common approach the goal to quantify geological processes. With increasing data resolution and new sensors future projects will even enable us to recognize more patterns and / or structures indicative of geological processes in tectonically active areas. This is crucial for the analysis of natural hazards like earthquakes, tsunamis and landslides, as well as those hazards that are related to climatic variability. The integration of remotely sensed data at different spatial and temporal scales with field observations becomes increasingly important. Many of presently highly populated places and increasingly utilized regions are subject to significant environmental pressure and often constitute areas of concentrated economic value. Combined remote sensing and ground-truthing in these regions is particularly important as geologic, seismicity and hydrologic data may be limited here due to the recency of infrastructural development. Monitoring ongoing processes and evaluating the remotely sensed data in terms of recurrence of events will greatly enhance our ability to assess and mitigate natural hazards.

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Dokument 1: Foliensatz | Dokument 2: Abstract

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Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung
Workshop vom 9. - 10. Februar 2006

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California
The Near Earth Asteroid Rendezvous (NEAR) satellite will travel to the asteroid 433 Eros, arriving there early in 1999, and orbit the asteroid for 1 year taking measurements that will map the surface features and determine its elemental composition. NEAR is the first satellite to use the rate-1/6 convolutional encoding on its telemetry downlink. Due to the scarcity and complexity of full decoders, APL designed and built a less capable but inexpensive version of the decoder for use in the integration, test, and prelaunch checkout of the rate-1/6 encoder. This paper describes the rationale for the design, how it works, and the features that are included.

Although Global Navigation Satellite Systems (GNSS) have been widely used in aviation, vehicle and marine navigation, and have also found non-safety railway applications (e.g. for locating trains in order to provide passengers with arrival and departure information), they still cannot be used in a standalone mode for safety critical railway applications such as automatic train control, automatic door opening or train integrity monitoring. This is because GNSS suffers from the line-of-sight problem, namely, GNSS might be unavailable when trains run through the areas with low satellite visibility (e.g. in urban canyons, deep cutting sides and tunnels). A potential solution is to integrate satellite navigation measurements with other sensors such as a track database, INS or an augmentation system. This thesis is concerned with the evaluation of the potential role of a track database for this purpose. A rigorous mathematical model for the integration of GNSS with the track database is developed. The key feature of this model is its ability to model errors in both GNSS measurements and the track database to achieve realistic performance statistics for the combined system. Knowledge of the position of the railway lines turns positioning, in principle, into a one dimensional problem. This thesis uses both simulated London area information and real railway satellite availability information from the Birmingham area to assess the improvements in Required Navigation Performance (RNP) parameters that might be obtained if railway authorities invest in a track database. The stimulation shows that the integration system improves the accuracy and increases the redundancy so that the system only needs as few as two satellites to calculate the position and accuracy, three satellites to computes the Receiver Autonomous Integrity Monitoring (RAIM) and four satellites to do the Fault Detection and Exclusion (FDE). The cost-efficient accuracy of track database and suitable RNPs are also discussed for safety-critical railway requirements.

The need for improved cloud parameterisations in a road surface temperature model is demonstrated. Case studies from early 1994 are used to investigate methods of tracking cloud cover using satellite imagery and upper level geostrophic flow. Two of these studies are included in this thesis. Errors encountered in cloud tracking methods were investigated as well as relationships between cloud height and pixel brightness in satellite imagery. For the first time, a one dimensional energy balance model is developed to investigate the effects of erroneous cloud forecasts on surface temperature. The model is used to determine detailed dependency of surface freezing onset time and minimum temperature on cloud cover. Case studies from the 1995/96 winter in Devon are undertaken to determine effects of differing scenarios of cloud cover change. From each study, an algorithm for predicting road surface temperature is constructed which could be used in future occurrences of the corresponding scenario of the case study. Emphasis is strongly placed on accuracy of predictions of surface freezing onset time and minimum surface temperature. The role o f surface and upper level geostrophic flow, humidity and surface wetness in temperature prediction is also investigated. In selected case studies, mesoscale data are also analysed and compared with observations to determine feasibility of using mesoscale models to predict air temperature. Finally, the algorithms constructed from the 1995/96 studies are tested using case studies from the 1996/97 winter. This winter was significantly different from its preceding one which consequently meant that the algorithm from only one scenario of the 1995/96 winter could be tested. An algorithm is also constructed from a 1996/97 winter case study involving a completely different scenario Recommendations for future research suggest testing of existing algorithms with guidance on additional scenarios.

Satellite systems have the advantage of global coverage and offer a solution for providing broadband access to end users. Local terrestrial networks and terminals can be connected to the rest of the world over Low Earth Orbit (LEO) satellite networks simply by installing small satellite interfaces. With these properties, satellite systems play a crucial role in the global Internet to support real-time and non-real-time applications. Routing in satellite networks, and the integration of satellite networks and the terrestrial Internet are the key issues to support these services. Furthermore, the developments in space technologies enable the realization of deep-space missions such as Mars exploration. The Interplanetary Internet is envisioned to provide communication services for scientific data delivery and navigation services for the explorer spacecrafts and orbiters of future deep-space missions. The unique characteristics posed by deep-space communications call for different research approaches from those in terrestrial networks. The objective of this research is to develop advanced architectures and efficient routing protocols for satellite and space networks to support applications with different traffic types and heterogeneous quality-of-service (QoS) requirements. Specifically, a new QoS-based routing algorithm (QRA) is proposed as a connection-oriented routing scheme to support real-time multimedia applications in satellite networks. Next, the satellite grouping and routing protocol (SGRP) is presented as a unicast routing protocol in a two-layer satellite IP network architecture. The border gateway protocol - satellite version (BGP-S) is then proposed as a unified routing protocol to accomplish the integration of the terrestrial and satellite IP networks at the network layer. Finally, a new routing framework, called the space backbone routing (SBR), is introduced for routing through different autonomous regions in the Interplanetary Internet. SBR provides a self-contained and scalable solution to support different traffic types through the Interplanetary Internet.

This thesis contains the results of a complete redesign effort, including development, integration, and experimental testing of a very small mechanical coupling mechanism. This mechanism is suitable for nano-satellites and uses a shape memory alloy (SMA) ring, press-fit into a metallic bushing to create a releasable interference joint. A detailed explanation of the techniques used to press-fit the SMA ring into the metallic bushing is included along with a description of why the SMA ring shrinks to its austenite phase upon heat activation and how it decouples from the metallic bushing. The couplingengineered to be as small as one tenth of a cubic centimeteris capable of achieving holding strengths in excess of 135 N (30 lbf). SMA characteristics and current release mechanisms are explained and tests are conducted to validate the holding strength achieved by the interference joint between the SMA and the metallic bushing. The design and part selection for each component of the Engineering Design Unit (EDU) is documented and launch conditions simulated to test the EDUs performance, releasability, and to validate the static holding force. Finally, this thesis describes the simulated integration of the EDU into a 3U CubeSat structure.

Die Verbindung von genetischen, physikalischen und zytologischen Daten ist entscheidend für die Genom- und Chromosomenanalyse. Obwohl Beta vulgaris (2n = 18) als wichtige Kulturpflanze und Untersuchungsobjekt der Grundlagenforschung eine intensiv analysierte Art darstellt, existiert bisher keine Verknüpfung zwischen Kopplungsgruppen (LG) und Chromosomen. B.-vulgaris-Chromosomen können zudem aufgrund fehlender morphologischer Unterscheidungsmerkmale bisher nicht einzeln identifiziert und klassifiziert werden. Somit sind zytogenetisch gewonnene Ergebnisse nicht ohne weiteres auf genetische Kopplungsgruppen und physikalische Karten übertragbar. Zytogenetische Methoden können zur Analyse struktureller Chromosomenveränderungen, zur Identifizierung und Lokalisierung von repetitiver DNA sowie zur Kartierung schwierig zu positionierender Marker verwendet werden. Ziel dieser Arbeit war es daher, ein FISH (Fluoreszenz-in-situ-Hybridisierung)-Verfahren zu etablieren, das die Kopplungsgruppen und Chromosomen der Zuckerrübe korreliert und die mikroskopische Identifizierung aller Chromosomenarme ermöglicht. Im Rahmen dieser Arbeit wurde ein FISH-Referenzkaryotyp der Zuckerrübe entwickelt. Durch ein Sondenset aus 18 BACs (bacterial artificial chromosome) sind alle Chromosomenarme der Zuckerrübe identifizierbar und werden mit den nördlichen und südlichen Enden der genetischen Kopplungsgruppen verknüpft. Somit ist eine einheitliche Nummerierung von Kopplungsgruppen und Chromosomen möglich. Durch die gleichzeitige Hybridisierung von chromosomenspezifischen BACs und den Satelliten-DNA-Sonden pAv34 und pBV VI beziehungsweise pEV und pBV wurden die Verteilungsmuster der Sequenzfamilien auf den Chromosomen ermittelt. Die gleichzeitige Hybridisierung aller vier repetitiven Sonden ergab ein chromosomenspezifisches Muster aus subtelomerischen, interkalaren und zentromerischen Signalen. Damit ist die Identifizierung aller B.-vulgaris-Chromosomen in einem einzelnen FISH-Experiment möglich. Zudem wurden dadurch die Chromosomen mit hohem Anteil an tandemartig angeordneten repetitiven Sequenzen identifiziert und die Chromosomenregionen lokalisiert, welche die Sequenzassemblierung behindern können. Sowohl das entwickelte BAC-Set als auch der Sondenpool aus repetitiver DNA unterscheiden die somatischen Metaphasechromosomen erstmals unabhängig von trisomen Linien. Da mit Hilfe der Satelliten-DNA-Sonden alle Chromosomen gleichzeitig markiert werden können, waren die spezifischen physikalischen Längen ermittelbar. Sie wurden mit den genetischen Längen der Kopplungsgruppen in Verbindung gebracht und deckten eine kopplungs-gruppenspezifische Rekombinationshäufigkeit zwischen 0,73 und 1,14 Mb/cM auf. Durch Hybridisierung der BACs und subtelomerischer beziehungsweise telomerischer Sonden auf Pachytänchromosomen wurde der Abstand der BACs sowie der in ihnen enthaltenen genetischen Marker zum physikalischen Chromosomenende abgeschätzt. An fünf Chromo-somenenden wurde ein deutlicher Abstand zwischen den Signalen des BACs und der terminalen Sonden festgestellt. Die zugehörigen Kopplungsgruppen sind demnach erweiterbar. Zudem wurden drei BACs mit nicht detektierbarem Abstand zum Chromosomenende durch FISH an gestreckten Chromatinfasern näher untersucht. Einer der drei BACs wurde eindeutig in unmittelbarer Nähe des Telomers nachgewiesen. Für dieses Ende (Chr 2N) ist die Wahrscheinlichkeit gering, dass die Kopplungsgruppe durch zusätzliche Marker erweitert werden kann; sie wird darum als abgeschlossen angesehen. Für die Enden Chr 4S und Chr 9S war der Abstand zwischen BAC und terminaler Sonde zu groß, um ihn durch Fiber-FISH zu ermitteln. Für sie sind weitere distal zu positionierende Marker wahrscheinlich. Weiterhin wurden bioinformatische Analysen an der verfügbaren B.-vulgaris-Genomsequenz RefBeet 1.0 durchgeführt. Scaffolds, welche die genetischen terminalen Marker enthalten, wurden bioinformatisch identifiziert und auf ihren Gehalt subtelomerischer und telomerischer Sequenzen untersucht. Vorhandene terminale Sequenzen sind ein Nachweis für eine terminale Lokalisierung der in-silico-Chromosomenabschnitte. Für drei Scaffolds mit zuvor ungeklärter Lage wurde dadurch das in-silico-Chromosom ermittelt beziehungsweise die nördliche oder südliche Position auf dem Chromosom dargestellt. Durch die Lokalisierung dieser Bereiche innerhalb der Sequenz in Bezug zum genetischen Marker und unter Berücksichtigung der Ergebnisse der Pachytän-FISH wurde die Strangorientierung von 16 Scaffolds ermittelt. Auf 14 Scaffolds wurden die Abstände der Marker zu den terminalen Sequenzen bestimmt. Der Median betrug etwa 196 kb. Für alle Kopplungsgruppenenden außer dem Norden von LG 2 und LG 4 ist das Vorhandensein weiterer distaler genetischer Marker wahrscheinlich. Satelliten-DNA ist innerhalb einer Art meist homogen, kann jedoch chromosomenspezifische Varianten ausbilden. Auf dem BAC-Marker für Chr 2N wurde durch Southern-Hybridisierung die subtelomerische Sequenzfamilie pAv34 detektiert. Von dem betreffenden BAC wurde eine Subklonbank erstellt. Durch Southern-Hybridisierung wurde der pAv34-Gehalt der Subklone analysiert. Positive Klone wurden sequenziert. Dabei wurden vier verschiedene vollständige pAv34-2N-Monomere detektiert. Im Vergleich mit pAv34-Volllängenmotiven aus der RefBeet 1.0 und dem Datensatz der nicht assemblierten Sequenzen der RefBeet 0.2 bilden die pAv34-2N-Einheiten mit pAv34-Kopien, die verschiedenen in-silico-Chromosomen und Contigs zugeordnet sind, eine Subfamilie. Aus den Sequenzen der Subklone wurden zwei Subklon-Contigs gebildet, die im in-silico-Chromosomenabschnitt von Chr 2N (Bvchr2.un.sca001) positioniert wurden. Dadurch wurden Regionen bisher unbekannter Sequenz entschlüsselt. Abweichungen zwischen den assemblierten Daten und den Subklonsequenzen deuten auf Assemblierungsfehler der Genomsequenz in repetitiven Bereichen hin. Die in dieser Arbeit erzielten Ergebnisse ermöglichen erstmalig die eindeutige Identifizierung aller B.-vulgaris-Chromosomen unabhängig vom Zellzyklusstadium und im Einklang mit genetischen Informationen. Zytogenetische sind jetzt mit molekularen Daten integrierbar und können verwendet werden, um den chromosomenspezifischen Satelliten-DNA-Gehalt aufzudecken und mögliche chromosomenspezifische Subfamilien zu identifizieren. Sie erlauben, physikalische Abstände zwischen Markern zu ermitteln und die Abdeckung von Kopplungsgruppen im terminalen Bereich zu untersuchen. Die Ergebnisse tragen dazu bei, Marker und nicht zugeordnete Contigs und Scaffolds zu kartieren, Ursachen für Lücken aufzudecken und damit die Sequenzdaten des Zuckerrübengenoms zu einer fortlaufenden, hochqualitativen Sequenz zu assemblieren. Die zytogenetischen Daten bilden zudem die Basis für zukünftige Untersuchungen struktureller Umbauten von Chromosomen, die während der Genomevolution stattfanden
The correlation of genetic, physical and cytological data is crucial for interdisciplinary genome and chromosome analyses. Beta vulgaris (2n = 18) is an important crop and an object of basic research. Although it is an intensely analysed species, its genetic linkage groups (LG) have not been assigned to chromosomes. Additionally, sugar beet chromosomes lack distinct morphological features and could therefore not be identified and classified individually. Consequently, results generated by cytogenetic methods can not be readily applied to genetic and physical maps. Cytogenetic approaches enable analysing structural chromosomal changes, identifying and localizing repetitive DNA, and mapping of markers which are difficult to place within linkage maps. Therefore, the main objective of this work has been the development of a FISH (fluorescence in situ hybridization) procedure that correlates LGs with chromosomes of sugar beet and that allows the microscopic identification of individual chromosome arms. In this work a FISH reference karyotype for sugar beet has been established. A set of 18 BACs (bacterial artificial chromosome) allows the unequivocal identification of each sugar beet chromosome and assigns them to the southern and northern ends of LGs. Hence, the chromosomes are numbered in accordance with the genetic map. The arm-specific BACs and the satellite DNA families pBV and pBV VI or pEV and pAv34 have been hybridized simultaneously to assign the distribution patterns of the highly abundant sequence families to chromosomes. Simultaneous hybridization of the four repetitive probes revealed a chromosome-specific pattern of subtelomeric, intercalary and centromeric signals. Thus, each of the sugar beet chromosomes can be identified in a single FISH experiment. Furthermore, chromosomes with a high content of repetitive DNA have been identified and chromosomal regions that may hinder the correct sequence assembly have been localized. The BAC set as well as the pooled satellite DNA probes discriminate the somatic chromosomes for the first time independently from trisomic lines. Since the chromosomes are differentially labelled with the satellite DNA probes their physical distances could be determined and correlated with genetic distances of the corresponding LGs. A LG-specific recombination frequency from 0.73 to 1.14 Mb/cM has been disclosed. BACs and subtelomeric or telomeric sequences have been hybridized simultaneously on pachytene chromosomes to estimate distances between BACs plus the markers they contain and the physical chromosome ends. Five BACs showed substantial distances to the physical chromosome ends; the corresponding LGs could thus be extended by additional markers. Furthermore, three BACs showing only minor distances to chromosome ends have been investigated in detail by fiber-FISH. One of these BACs was localized closely adjacent to the telomere. For this chromosome end (Chr 2N) it is unlikely that the LG could be extended distally by additional markers and is therefore considered to be closed. The BACs for the chromosome ends Chr 4S and Chr 9S have been too distant from the terminal probe to be bridged by fiber-FISH. For them it is likely that further markers can be placed distally. Furthermore, the B. vulgaris genomic sequence RefBeet 1.0 has been investigated. Scaffolds containing terminal genetic markers have been identified bioinformatically and analysed for the content of subtelomeric and telomeric sequences. The occurrence of terminal sequences confirms the terminal localization of in silico chromosome segments. Three scaffolds with an initially unknown position could thus be allocated to in silico chromosomes and to the northern or southern position on the chromosome. The strand orientation of 16 scaffolds has been determined based on the localization of terminal sequences in relation to the genetic marker considering the results of FISH on pachytene chromosomes. The distance between markers and terminal sequences has been determined for 14 scaffolds. The median is 196 kb. It is likely that further markers can be placed distally from all LG ends except for the north of LG 2 and LG 4. Satellite DNA is usually homogenous within one species; however, it can form chromosome-specific variants. Southern hybridization revealed that the BAC marker for Chr 2N contains the subtelomeric sequence family pAv34. The BAC has been subcloned and the pAv34 content of the subclones has been analysed by Southern hybridization. Positive clones have been sequenced. Thereby, four pAv34-2N monomeres have been detected. Compared to full-length pAv34 motives derived from the RefBeet 1.0 and from unassembled sequence data of the RefBeet 0.2 the pAv34-2N units form a subfamily together with pAv34 copies assigned to different in silico chromosomes and contigs. The subclone sequences have been assembled to two subclone contigs, which have been positioned within the in silico chromosome segment of Chr 2N (Bvchr2.un.sca001). Thereby, regions of unknown sequence have been decoded and probable misassemblies in repetitive regions within the RefBeet 1.0 have been disclosed. The results obtained in this work enable the identification of all sugar beet chromosomes independently from their stage of cell division and in accordance with genetic information. Cytogenetic data are integrated with molecular data and can be used for identifying the chromosome-specific distribution of repeats and chromosome-specific repeat variants. They enable determining physical distances between markers and investigating the terminal coverage of LGs. The results support the correct mapping of markers and unassigned contigs, uncover reasons for gaps within maps and sequence assemblies, and thus contribute to assembling data into a continuous high quality genome sequence of sugar beet. Moreover, the cytogenetic data represent the basis for future investigations of structural chromosomal changes that took place during evolution

Cette these presente une recherche qui aboutit a une methode permettant la detection et la localisation du changement de l'occupation du sol en milieu periurbain, par traitement d'images numeriques spot hrv integrees dans un systeme d'information geographique (sig). Il s'agit d'une procedure qui, au travers de la mise en relation des donnees multisources (images-satellite et cartes d'occupation du sol), permet de determiner de facon systematique des changements d'affectation des zones en milieu periurbain. La technique retenue utilise le traitement par zone en considerant six indices : le canal panchromatique, l'indice de vegetation, l'indice de brillance, l'ecart type local, l'indice de mineralisation recente et l'indice +non-eau;. Pour chaque indice des bornes de stabilite sont definies en fonction des parametres statistiques de chaque poste de la legende consideree. Le resultat final se traduit par une carte de changements d'affectation des zones
This thesis presents a investigation which lead to a methodology proposal to locate and detect land cover changes in the urban fringe through the combination of spot hrv satellite image processing in a geographic information system (gis). Using multi-source data (satellite images and land cover maps) the discussed procedure allows to systematically determinate affectation zone changes in the urban fringe. The chosen technique relies on zone analysis applying six indexes: the panchromatic band, the vegetation index, the brightness index, the standard deviation, the recent mineralization index and the +nonwater; index. For each one of these indexes a stability limit was defined regarding the statistical parameters of the considered classes. The final result is materialised on a zone affectation change map

L'observation satellite offre l'opportunité unique d'une couverture globale et d'un suivi temporel continu en météorologie et climatologie. On rencontre toutefois de nombreuses difficultés dans leur exploitation, ce qui requiert l'utilisation de techniques d'optimisation dans les diverses étapes de leur traitement. On traitera dans cette thèse deux questions : (1) au niveau du traitement des données satellite, en amont de la chaîne de restitution, et (2) en aval, pour l'intégration des multiples produits satellites disponibles. On propose ainsi une nouvelle approche de compression/sélection de canaux (les « Bottlenecks Channels ») pour réduire la dimension des données hyper-spectrales (dans l'infrarouge avec l'instrument IASI et dans les microondes pour un nouveau concept de sondeur). On développe également un nouveau schéma d'intégration de multiples produits satellites pour l'étude du cycle de l'eau (surface, océan et atmosphère). Cette approche d'intégration permet de rendre plus cohérentes les composantes du cycle de l'eau. Elle est présentée ici dans le contexte du cycle de l'eau méditerranéen
Satellite observation offers the unique opportunity for global coverage and continuous temporal monitoring in meteorology and climatology. However, there are many difficulties in their exploitation, which requires the use of optimization techniques at the different steps of their processing. This thesis will deal with two questions: (1) the processing of satellite data before the restitution, and (2) the integration of the multiple satellite products available. A new approach for channel compression/selection (Bottlenecks Channels) is proposed to reduce the dimension of hyperspectral data (in the infrared with the IASI instrument and in microwaves for a new sounder concept). A new scheme is also developed to integrate multiple satellite products for the study of the water cycle (surface, ocean and atmosphere). This integration approach makes the components of the water cycle more coherent to each other. It is presented here in the context of the Mediterranean water cycle

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada
The Central Control Unit (CCU) for a decentralised on-board base-band telemetry system is designed for use in launch vehicle missions of the Indian Space Research Organisation (ISRO). This new design is a highly improved and miniaturised version of an earlier design. The major design highlights are as follows: usage of CMOS Field Programmable Gate Array (FPGA) devices in place of LS TTL devices, high level user programmability of TM format using EEPROMs, usage of high density memory for on-board data storage and delayed data transmission, HMC based pre-modulation filter and final output driver etc. The entire system is realised on a single 6 layer MLB and is packaged on a stackable modular frame. This design has resulted in a 1:4 reduction in weight, 1:4 reduction in volume, 1:5 reduction in power consumption and 1:3 reduction in height in addition to drastic reduction of part diversity and solder joints and thus greatly increased reliability. This paper discusses the design approach, implementation details, tools used, simulations carried out and the results of detailed qualification tests done on the realised qualification model.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada
Lunar Prospector’s project engineering staff selected a Windows PC platform as the RF test console for the Lunar Prospector spacecraft. The spacecraft test team chose the PCbased RF test console because the PC provides a low-cost, common platform with a graphical user interface. The PC provides point-and-click, menu-driven windows that are common throughout the satellite factory. The PC RF test console is being used to exercise the Lunar Prospector spacecraft RF link for RF commanding, telemetry, and ranging signals during factory test, including thermal vacuum chamber testing. For spacecraft command and control at the factory, the PC-based RF test console is networked to a UNIX workstation over RS-422. The PC RF test console and spacecraft interface are controlled through a coax switch residing in a test rack next to the workstation. The PC RF test console is connected directly to the Lunar Prospector spacecraft using coax cable through the spacecraft Telemetry, Commanding, & Ranging (TC&R) RF antenna hat for both transmit and receive functions. The PC RF test console is also connected hard-line to the spacecraft transponder through the transponder RS-422 connection. This connection provides the ability for spacecraft telemetry to be received at the PC at RF or baseband. The same hard-line spacecraft telemetry data is provided to the UNIX workstation for comparison. NASA’s Lunar Prospector project is the first of the Discovery series of “faster, better, cheaper” missions to be competitively awarded. Lunar Prospector project funding was capped by NASA to ensure that no overruns would occur. The mission was funded to support the scientific community’s desire to verify the presence of ice on the moon and collect environmental data to understand the dynamics that may have led to polar ice deposits. The Lunar Prospector mission received funding in 1996 with a launch planned for September 1997

Soil attributes directly influence on its surface temperature. Although there are several studies using soil spectra obtained from satellites, soil evaluation through Land Surface Temperature (LST) is still scarce. The broad availability of satellite thermal data and the development of algorithms to retrieve LST facilitated its use in soil studies. The objective of this study was to evaluate soil LST variations due to its composition and verify the potential of using LST on soil attributes quantification, also integrated with reflectance spectra and elevation data. The study area (198 ha) is located in Sao Paulo state, Brazil, and had plowed bare soil during the satellite image acquisition date. Soil samples were collected in a regular grid of 100 x 100 m (depths: 0-0.2 m and 0.8- 1.0 m); soil granulometry, organic matter (OM) and iron oxides were determined by wet chemistry analysis. In this study, an image of Landsat 5 was used for extracting LST using the inversion of Planck\'s function in band 6 (10,400 - 12,500 nm), and land surface emissivity was estimated using Normalized Difference Vegetation Index threshold method. Reflectance values were extracted from bands 1, 2, 3, 4, 5 and 7. Models for soil attributes quantification were performed using Linear Regression (LR), with samples from 62 auger points distributed in 14 toposequences. Simple LR was applied for generating prediction models based on LST and on elevation data (extracted from a Digital Elevation Model). Multiple LR was applied in order to generate prediction models using atmospherically corrected spectral reflectance from Visible, Near-Infrared and Shortwave infrared (Vis-NIR-SWIR) bands as predictors, and also for the prediction of soil attributes using simultaneously Vis-NIR-SWIR, LST and elevation data, and only significant variables identified by T-tests were used. Predictive performance of models was assessed based on adjusted coefficient of determination (R2adj), Root Mean Squared Error (RMSE, g kg-1) and Ratio of Performance to Interquartile Range (RPIQ) obtained in validation. Ordinary kriging was also performed and the resulted interpolated surfaces were compared to the maps obtained from the best LR model. There was significant correlation between soil attributes and reflectance, LST and elevation data, and soils with clay texture were differentiated from sandy soils based on LST mean values. For all soil attributes, models using only elevation presented the worst performance; models using only LST, moderate performance; and using Vis-NIR-SWIR bands, good predictive performance. For clay, the best model obtained had bands 4-7, LST and elevation as predictors; for sand and iron oxides, the best model had bands 4-7 and LST; for OM, band 4, band 7 and LST. The use of LST for estimating soil attributes increases the predictive performance of multiple LR models when associated with other variables obtained through remote sensing, particularly surface reflectance data, improving the validation of models reaching high R2adj, high RPIQ and low RMSE values. Maps for sand, OM and iron oxides obtained through ordinary kriging outperformed those obtained for the same attributes using LR models based on RS co-variables, and for clay, both approaches reached the same accuracy level. Mapping of soil clay, sand, OM and iron oxides contents through multiple LR models using Landsat 5 products is a simple and easy to reproduce technique, appropriate for soil attributes mapping in bare soil agricultural areas.
Os atributos do solo influenciam diretamente na sua temperatura de superfície. Apesar de existir vários estudos utilizando espectros de solos obtidos de satélite, a avaliação do solo por meio da Temperatura de Superfície Terrestre (em inglês Land Surface Temperature, LST) ainda é escassa. A ampla disponibilidade de dados termais de satélite e o desenvolvimento de algoritmos para derivar a LST facilitou o seu uso em estudos de solos. O objetivo desse trabalho foi avaliar variações da LST do solo devidas à sua composição e verificar o potencial de uso da LST na quantificação de atributos do solo, também integrada com dados de espectros de reflectância e elevação. A área de estudo (198 ha) está localizada no estado de São Paulo, Brasil, e estava com solo exposto e arado na data de aquisição da imagem de satélite. Amostras de solo foram coletadas em um grid regular de 100 x 100 m (profundidades: 0.02 m e 0.8-1.0 m); a granulometria do solo, matéria orgânica (MO) e óxidos de ferro foram determinados via análises físicas e químicas laboratoriais. Neste estudo, uma imagem do Landsat 5 foi utilizada para extrair a temperatura de superfície usando a inversão da função da Lei de Planck na banda 6 (10.400 - 12.500 nm), e a emissividade de superfície foi estimada utilizando o método do limiar do Índice de Vegetação da Diferença Normalizada. Valores de reflectância das bandas 1, 2, 3, 4, 5 e 7 foram extraídos. Modelos para quantificação de atributos do solo foram feitos usando Regressão Linear (RL), com amostras de 62 pontos de tradagem distribuídos em 14 topossequências. A RL simples foi aplicada para gerar modelos de predição baseados na LST e também na elevação (extraída de um modelo digital de elevação). A RL múltipla foi aplicada para gerar modelos de predição usando os espectros de reflectância com correção atmosférica das bandas do Visível, Infravermelho próximo e Infravermelho de ondas curtas (Vis-NIR-SWIR) como preditores; também foi aplicada para predição de atributos do solo usando simultaneamente dados do Vis-NIR-SWIR, LST e elevação, e apenas variáveis significativas identificadas por teste T foram usadas. A performance preditiva dos modelos foi avaliada baseada no coeficiente de determinação ajustado (R2adj), raiz do erro quadrático médio (RMSE, g kg-1) e razão de desempenho do intervalo interquartil (RPIQ) obtidos na validação. A krigagem ordinária também foi feita e as superfícies interpoladas resultantes foram comparadas com o melhor modelo de RL. Houve correlação significativa entre os atributos do solo e dados de reflectância, LST e elevação, e solos com textura argilosa foram diferenciados de solos arenosos com base em valores médios de LST. Para todos os atributos do solo, os modelos usando apenas elevação apresentaram a pior performance, modelos usando somente LST, performance moderada, e usando as bandas do Vis-NIR-SWIR, boa performance preditiva. Para argila, o melhor modelo obtido teve as bandas 4-7, LST e elevação como preditores; para areia e óxidos de ferro, o melhor modelo teve as bandas 4-7 e LST; para MO, banda 4, banda 7 e LST. O uso da LST para estimar atributos do solo aumenta a performance preditiva de modelos de RL múltipla quando associada a outras variáveis obtidas via sensoriamento remoto (SR), particularmente dados de reflectância de superfície, melhorando a validação dos modelos atingindo altos valores de R2adj e RPIQ e baixos valores de RMSE. Os mapas para areia, MO e óxidos de ferro obtidos via krigagem ordinária superaram aqueles obtidos para os mesmos atributos usando modelos de RL baseados em co-variáveis obtidas via SR, e para argila, ambas abordagens atingiram o mesmo nível de acurácia. O mapeamento dos conteúdos de argila, areia, matéria orgânica e óxidos de ferro do solo via modelos de RL múltipla utilizando produtos do Landsat 5 é uma técnica simples e fácil de reproduzir, apropriada para o mapeamento de atributos do solo em áreas de agricultura com solo exposto.

Ce travail de thèse s’inscrit dans le contexte actuel d’une très forte augmentation de la densité d’intégration des systèmes électroniques pour les équipements de communications, de localisation ou de surveillance. Le déploiement de ces systèmes doit aussi répondre à une demande croissante de flexibilité en termes de fréquences, de puissance ou de couverture. La flexibilité en fréquence peut être simultanée avec des dispositifs multi-bandes ou sélective par reconfiguration de la bande de fréquence. La flexibilité en puissance permet de minimiser la consommation du système et la flexibilité de couverture d’orienter le faisceau vers la cible afin d’optimiser le bilan de liaison ou au contraire se protéger d’une source de bruit. L’augmentation de l’efficacité et de la compacité passe par le regroupement de fonctions élémentaires (LNA/filtre/antenne) qui permet de réduire les étages d’interconnexion et de prendre en compte les interactions entre les différents éléments. L’objectif premier de ce projet est donc de développer une méthodologie de conception conjointe de l’antenne et des circuits associés (filtres et LNA) pour atteindre des performances (rayonnement, efficacité, etc.) optimales avec un dispositif intégré et compact
This work takesplace in the context of developingelectronic systems for communications equipment, localization or monitoringequipment with a high integration density. The deployment of these systems must also meet a growing demand for flexibility in terms of frequencies, power or coverage. The frequency flexibility can be simultaneous with multiband devices or selective by reconfiguring the frequency band. The power flexibility enables to minimize consumption of the system and the coverage flexibility to direct the beam to the target to optimize the budget link or otherwise protect a source of noise. The increase in efficiency and compactness passes through the combination of elementary functions (LNA / filter / antenna) that reduces interconnect floors and considering the interactions between the different elements. The primary objective of this project is to develop a co-design methodology of the antenna with the associated circuits (filters and LNA) to achieve optimal performances (radiation,efficiency, ...) with an integrated and compact device

Thesis (M.S. in Systems Technology (Command, Control, and Communication (C3)) and M.S. in Space Systems Operations)--Naval Postgraduate School, June 2009.
Thesis Advisor(s): Newman, James H. "June 2009." Description based on title screen as viewed on 13 July 2009. Author(s) subject terms: Satellite, CubeSat, NPS-SCAT, solar cell tester, communications, antenna patch, dipole antenna, beacon, TT&C, frequency coordination, Navy-Marine Corps Spectrum Center Includes bibliographical references (p. 197-201). Also available in print.

L’émergence des satellites très haut débit pour la couverture des zones rurales s’accompagne de nombreuses contraintes technologiques. Dans le cadre du plan France très haut débit, le projet THD-sat proposé par le CNES se base sur l’utilisation des bandes Q et V pour assurer les liaisons avec les stations au sol et libérer de la ressource sur la bande Ka communément utilisée par les satellites ancienne génération. Avec la montée en fréquence, les besoins en termes de filtrage deviennent très stricts nécessitant des considérations particulières. Le premier chapitre reprend le contexte de l’étude et expose les différents éléments permettant de justifier le choix de la technologie SIW qui profite à la fois des bons facteurs de qualité des modes volumiques se propageant dans le substrat et de l’aisance du procédé technologique et de l’intégration des structures planaires. Les performances des cavités SIW restent néanmoins intimement liées à l’épaisseur de substrat qui doit être augmentée pour atteindre de meilleurs facteurs de qualité. L’augmentation de l’épaisseur de substrat s’accompagne de deux principales limitations : le rallongement des fils de « bonding » utilisés pour le câblage du filtre à son environnement MIC d’épaisseur 254 μm et l’élargissement de la ligne d’accès 50 Ω induisant des problèmes de discontinuités et d’excitations de modes parasites. L’approche suivie consiste à considérer des formes 3D permettant l’adaptation de mode et d’épaisseur entre une ligne microruban sur substrat de 254 μm d’épaisseur et le SIW d’épaisseur plus importante. Une nouvelle transition 3D est dès lors imaginée. Le chapitre II reprend les différents procédés technologiques utilisés pour la mise en forme et la métallisation des substrats 3D. Les substrats considérés sont l’alumine et la silice fondue mis en forme par ablation laser et le thermoplastique COP mis en forme par moulage. La principale limitation de l’ablation laser concerne les épaisseurs de substrat accessibles. Nous nous limitons à 635 μm dans le cas de l’alumine et à 500 μm dans le cas de la silice fondue. Le moulage polymère permet de s’affranchir de cette limitation et de viser des substrats plus épais (2 mm pour la solution COP).Le chapitre III reprend les étapes de conception des différentes solutions de filtrage avec la nouvelle transition 3D. Des résultats de mesures de différents prototypes réalisés sont par ailleurs présentés. Ces résultats sont globalement encourageants mais nécessitent d’être davantage développés pour être mieux exploitables
The emergence of satellite high-speed internet for the coverage of rural zones is accompanied by numerous technological constraints. The current trend is to use higher frequency bands to release the satellite capacity for users. The increasing frequency requires new considerations especially for filtering needs which become notably strict in terms of performance and integration in small integrated circuits. This work introduces filtering solutions based on high quality factor Substrate Integrated Waveguides (SIW) using a novel 3D transition for a better integration in widely planar Hybrid ICs.The first chapter introduces the study’s context and the different elements justifying the use of the SIW technology.In fact, these structures profit from both the good quality factors of TE-modes propagating in the substrate and the easy fabrication process and integration of planar circuits. However, to increase the SIW quality factor, the substrate’s height should be increased which induces interconnection limitations such as long bond wires with high parasitic effects and large microstrip access lines with discontinuity problems and the propagation of parasitic modes. The adopted approach consists in imagining 3D shapes providing both mode and thickness matching between a microstrip line etched on a thin substrate and a high substrate SIW.The second chapter introduces the different manufacturing processes used for the substrate’s shaping and metallization. Three substrates are considered: Alumina, fused Silica and Cyclo Olefin Polymer COC. Alumina is widely used in space applications and has a well-mastered process. For equivalent dielectric losses, fused silica has a lower permittivity for bigger structures with less manufacturing tolerance sensitivity. Both Alumina and fused silica substrates are shaped using a laser ablation. The reachable substrate’s height using this machining method is relatively low. The polymer solution (COP) is elaborated using a molding process allowing higher substrates heights.The last chapter outlines the design steps of the different solutions and the measurement results of the first prototypes. These results are on the whole encouraging but require further development

Les systèmes de navigation par satellite (GNSS) font partie de notre quotidien. On peut présentement les trouver dans un ensemble d’applications. Avec les nouveaux besoins, des nouveaux enjeux sont aussi apparus : le traitement du signal dans les environnements urbains est extrêmement complexe. Dans cette thèse, le traitement des signaux GNSS à faible puissance est abordé, en particulier dans la première phase du traitement, nommé acquisition de signal. Le premier axe de rechercheporte sur l’analyse et la compensation de l’effet Doppler dans l’acquisition. Le décalage Doppler perçu par l’utilisateur est un des paramètres principaux pour la configuration du module d’acquisition. Dans cette étude, des solutions sont proposées pour trouver le meilleur compromis sensibilité-complexité propre à l’acquisition. En deuxième axe, la caractérisation des détecteurs différentiels est abordée, en particulier la quantification de sa sensibilité. Pour l’acquisition des signaux faibles, après une première phase d’intégration cohérente, il faut passer par une intégration «postcohérente» (noncohérente ou différentielle.) L’analyse exécutée ici permet de meilleur identifier le meilleur choix entre les deux possibilités. Le troisième axe de recherche est consacré à la méthode de Détection Collective (CD), une innovation qui fait l’acquisition simultanée de tous les signaux visible par le récepteur. Plusieurs analyses sont réalisées incluant l’amélioration de la procédure de recherche de la CD, et l’hybridisation avec l’acquisition standard. Enfin on effectuel’analyse de la CD dans un contexte multi-constellation, en utilisant simultanément des vrais signaux GPS et Galileo
Satellite navigation (GNSS) is a constant in our days. The number of applications that depend on it is already remarkable and is constantly increasing. With new applications, new challenges have also risen: much of the new demand for signals comes from urban areas where GNSS signal processing is highly complex. In this thesis the issue of weak GNSS signal processing is addressed, in particular at the first phase of the receiver processing, known as signal acquisition. The first axe of research pursued deals with the analysis and compensation of the Doppler effect in acquisition. The Doppler shift that is experienced by a user is one of the main design drivers for the acquisitionmodule and solutions are proposed to improve the sensitivity-complexity trade-off typical of the acquisition process. The second axe of research deals with the characterization of differential GNSS detectors. After a first step of coherent integration, transition to post coherent (noncoherent or differential) integration is required for acquiring weak signals. The quantification of the sensitivity of differential detectors was not found in literature and is the objective of this part of the research. Finally, the third axe of research is devoted to multi-constellation Collective Detection (CD). CD is an innovative approach for the simultaneous processing of all signals in view. Severalissues related to CD are addressed, including the improvement of the CD search process and the hybridization with standard acquisition. Finally, the application of this methodology in the context of a multi-constellation receiver is also addressed, by processing simultaneously real GPS and Galileo signals

Approved for public release; distribution is unlimited
The open sea is an area where numerous legal activities occur such as trade, transportation, and scientific research; but it is also a place that attracts persons with illegal, criminal, and terrorist intentions. Naval nations, often acting in alliance, conduct operations to stop this illegal activity. Maritime-interdiction operations (MIO) are the usual type of operation employed, and, because of their nature, require robust communications and uninterrupted flow of information. Establishing communications and networks in the open seas via terrestrial means is possible only in certain areas and it is not feasible around the clock. Therefore, the distribution of the data and information needed for maritime-interdiction operations is significantly limited as to speed, accuracy and efficiency. This thesis examines how small satellites in general can be integrated in MIO ad hoc networks and how their advantages and disadvantages affect the flow of information among the nodes.

Thesis (M.S.)--Missouri University of Science and Technology, 2010.
Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 21, 2010) Includes bibliographical references (p. 146-149).

Chapter 1 The mating systems of two annually-reproducing hammerhead sharks (scalloped hammerhead Sphyrna lewini, bonnethead Sphyrna tiburo) were investigated by genetically-profiling 82 litters (902 embryos). Unlike three biennially-reproducing shark species previously studied that are polygynandrous, genetic monogamy was common in females of both of these hammerheads (S. lewini [70.6 % of litters], S.tiburo [85.4-62.5%]), suggesting a polygynous mating system overall. These mating system characteristics suggest that hammerheads may have lower ratios of effective to census population sizes than polygynandrous sharks, adding to conservation concerns for these species. Results suggest that female mating behavior may play a more limited role in determining the population-level of multiple paternity than currently envisioned in sharks, with the interplay between male mating tactics and female reproductive periodicity (biennial or annual) perhaps being more influential. Two lines of evidence infer that multiple paternity is associated with larger females in S. tiburo: mothers of multi-sired litters are significantly larger than mothers of single paternity litters in West Florida and the frequency of multiple paternity is significantly higher in South Carolina, where females are larger. Large females may therefore produce larger, more genetically-diverse litters in some shark species and could contribute disproportionately to recruitment and population genetic diversity, increasing their importance from a conservation perspective. Chapter 2 Although most shark species have relatively small body-sizes as adults (<100 cm total length), little is known about the genetic population structure and lineage diversification of small sharks. Mitochondrial control region and nuclear internal transcribed spacer 2 sequences combined with three independent microsatellite loci all concordantly show that the diminutive hammerhead shark Sphyrna tiburo (bonnethead) consists of two highly divergent lineages from South Carolina, U.S.A. to Belize, a coastal distance of less than 6000 km. One lineage was restricted to Belize, while the other was almost completely restricted to five North American sampling sites (pairwise CR ΦST = 0.891-0.915, microsatellite Fst=0.277-0.319). This represents the highest degree of population structure recorded concordantly at both mitochondrial and nuclear loci in a shark along a continuous coastline. Regional measures of population structure and genetic divergence in this diminutive hammerhead shark mirror but exceed values obtained for larger shark species over the same sampling range and are comparable to those observed in a larger congener on a global scale. Direct evidence of interbreeding between these lineages indicates that speciation has not yet occurred. Gene-flow was generally high among North American populations, but there was evidence that female-mediated gene flow is moderately restricted between subtropical Florida Bay and higher latitude populations, suggesting that changes in latitude and climate regime may help drive population genetic differentiation in this species. This study is the second to reveal unexpectedly high lineage diversification within Atlantic hammerhead sharks, which suggests that further genetic surveys are required to fully understand and conserve hammerhead shark biodiversity in this region. Chapter 3 Dried fins from the scalloped hammerhead shark (Sphyrna lewini) are highly-valued for utilization in the Asian delicacy shark-fin soup. While global landings of this species annually measure in the millions to supply this market, Western Atlantic populations have collapsed and are now considered to be endangered. This study reveals that Western Atlantic S. lewini comprise at least three distinct management units that will be reliant on intrinsic reproduction rather than immigration for rebuilding (MU’s: U.S.A., Central American Caribbean and Brazil; overall ΦST=0.64). These MU’s are sufficiently differentiated from each other, eastern Atlantic and Indo-Pacific stocks to use mixed-stock analysis (MSA) to better understand the impact of the fin trade on sharks of this region. Stock of origin was determined for 57 Hong Kong market-derived S. lewini dried fins, revealing that contemporary trade is globally-sourced with a substantial presence of fins from imperiled Western Atlantic stocks. Results are used to formulate regional management recommendations and to develop monitoring strategies for the Asian fin trade that could dramatically improve global conservation of S. lewini and serve as a template for other sharks impacted by this trade. Chapter 4 Longline sampling (83 sets) supplemented with 6 pop-off archival tag (PAT) deployments were used to characterize vertical habitat use by Caribbean reef sharks, Carcharhinus perezi, at Glover’s reef atoll, Belize. Longline CPUE in two shallow reef habitats (lagoon < 18m depth, fore-reef < 40 m depth) underwent significant nocturnal increases for sharks larger than 110 cm total length (TL) but not for smaller sharks. Nocturnal CPUE of small sharks increased in the lagoon and decreased on the fore-reef, suggesting movements to avoid larger conspecifics. PAT deployments (7-20 days) indicate that large C. perezi generally increased the amount of time they spent in the upper 40 m of the water column during the night and have a much wider depth and temperature range than previously thought (0 to 356 m, 31-12.4oC). The wide vertical range of this top-predator reveals ecological coupling of deep and shallow reef habitats and has implications for place-based conservation. Chapter 5 Marine Protected Areas (MPAs) are increasingly advocated for the restoration and conservation of coral reef ecosystems, yet given the typically small size of most no-take MPAs it remains unknown how effective this strategy will be for roving, top-level predators such as sharks. Movement patterns of Caribbean reef sharks, Carcharhinus perezi, tagged with coded acoustic transmitters were monitored with an array of up to 22 underwater receivers from May 2004 to October 2006 at Glover’s Reef Marine Reserve, a zoned MPA in Belize. Thirty one tagged sharks ranged in size from 80-215 cm total length [TL], spanning young-of-the-year to mature specimens of both genders. Twenty five of these sharks provided data for more than one week after tagging. Individual sharks were detected within the array on from 5 to 464 days and all but four were predominantly detected on the receiver(s) nearest their original capture. Although daily movements of up to 20-50 km were documented by large sharks (>110 cm TL), most individuals were detected at Glover’s Reef on an almost daily basis throughout the year and appear to be residents of this reef system. Small sharks were documented to be residents for at least six months. The daily dispersal ranges and distribution of sharks tracked in this study suggest that typically small-sized no-take zones will be of limited value for reef shark conservation. However, the long-term residency and site-fidelity of large and small C. perezi to this reef system in its entirety indicates that nesting this no-take zone within a broader ocean zoning plan tailored to protect large roving predators achieves the scale necessary to provide meaningful protection for these ecologically important, threatened predators.

Thesis (Ph. D.) -- University of Maryland, College Park, 2008.
Thesis research directed by: Dept. of Geography. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

Decisions for the conservation of biodiversity and sustainable management of natural resources are typically related to large scales, i.e. the landscape level. However, understanding and predicting the effects of land use and climate change on scales relevant for decision-making requires to include both, large scale vegetation dynamics and small scale processes, such as soil-plant interactions. Integrating the results of multiple BIOTA subprojects enabled us to include necessary data of soil science, botany, socio-economics and remote sensing into a high resolution, process-based and spatially-explicit model. Using an example from a sustainably-used research farm and a communally used and degraded farming area in semiarid southern Namibia we show the power of simulation models as a tool to integrate processes across disciplines and scales.

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Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung
Workshop vom 9. - 10. Februar 2006.

O desenvolvimento de uma nova geração de sensores nos últimos 20 anos consolidou as imagens de sensoriamento remoto como uma importante fonte de dados para estudos ambientais e fenômenos geográficos em larga escala. É grande a variedade de resoluções (espacial, temporal e espectral) das imagens de sensoriamento remoto, desde pancromáticas até imagens polarimétricas. Apesar da grande experiência em coleta, armazenamento e distribuição de imagens e da diversidade de ferramentas computacionais para processamento e análise, ainda é difícil de se encontrar sistemas que apresentem um ambiente integrado para transformar imagens multi-temporais e de diversas resoluções em informação útil. Tendo em vista este panorama, a contribuição desta tese é dupla. Em primeiro lugar, propomos e implementamos uma nova ferramenta, seguindo os padrões de código-fonte aberto (\textit{Free and Open Source Software - FOSS}) , para integrar métodos de análise de imagens com técnicas de mineração de dados, visando produzir um ambiente computacional extensível e focado no usuário, aplicado à extração de informações e à descoberta de conhecimento em grandes bases de dados geométricos. Esta ferramenta é chamada GeoDMA - \textit{Geographic Data Mining Analyst} (mineração de dados geográficos). GeoDMA integra técnicas de sementação de imagens, extração e seleção de atributos, classificação, métricas da ecologia da paisagem, métodos de análise multi-temporal para detecção de mudanças e classificação por métodos de árvores de decisão adaptados à mineração de dados espaciais. O sistema agrega imagens de sensoriamento remoto com outros tipos de dados geográficos através do acesso a bancos de dados locais ou remotos. GeoDMA também provê métodos de simulação para avaliar a acurácia dos modelos, e ferramentas para análise espaço-temporal, incluindo um esquema de visuação de perfis temporais que auxilia os usuários a descrever padrões em eventos cíclicos. Em segundo lugar, desenvolvemos um novo método para analizar dados espaço-temporais baseados na transformação dos perfis em coordenadas polares, o que permite a geração de um novo conjunto de atributos que aumenta a acurácia da classificação de imagens multi-temporais. O sistema GeoDMA foi construído como uma extensão do SIG Terra View, e por isso mapas temáticos e demais resultados são produzidos rapidamente, aproveitando-se das funcionalidades deste SIG. Para demonstrar as ferramentas do GeoDMA, cinco (5) casos de estudo, aplicados em diferentes contextos de detecção de uso e cobertura da terra, foram realizados usando dados de diferentes domínios. A avaliação destes experimentos, do ponto de vista do usuário, mostrou que a ferramenta obteve os resultados com um nível de integração não encontrado em sistemas semelhantes.
The deployment of a new generation of sensors over the last 20 years has made satellite remotely sensed imagery a very important source of spatial data available for environmental studies of large-scale geographic phenomena. The variety of spatial, temporal and spectral resolutions for remote sensing images is large, ranging from panchromatic images to polarimetric radar images. Despite the great experience in image data gathering and distribution and a diversity of image processing and analysis toolboxes, it is still difficult to find image analysis systems that provide a straightforward fully integrated environment to transform multi-temporal and multiresolution satellite image data into meaningful information. Taking this into account, the contribution of this thesis is two-fold. Firstly, we propose and implement a new toolbox, developed under the Free and Open Source Software (FOSS) foundation, for integrating remote sensing imagery analysis methods with data mining techniques producing a user-centered, extensible, rich computational environment for information extraction and knowledge discovery over large geographic databases. The toolbox is called GeoDMA - Geographic Data Mining Analyst. It integrates techniques of segmentation, feature extraction, feature selection, classification, landscape metrics and multi-temporal methods for change detection and analysis with decision-tree based strategies adapted for spatial data mining. It gathers remotely sensed imagery with other geographic data types using access to local or remote databases. GeoDMA provides simulation methods to assess the accuracy of process mo dels as well as tools for spatio-temporal analysis, including a visualization scheme for temporal profiles that helps users to describe patterns in cyclic events. Secondly, we develop a new approach for analyzing spatio-temporal data based on a polar coordinates transformation that allows creating a new set of features which improves the classification accuracy of multi-temporal image databases. As GeoDMA was built on top of Terra View GIS, thematic maps and other results can be produced rapidly, taking advantage of the basic GIS functionalities. To demonstrate the features of GeoDMA toolbox, five (5) case studies, applied in contexts of land use and land cover change, were carried out in different application domains. Evaluations of these experiments pointed out that the GeoDMA toolbox achieved results with a level of integration, from a user perspective, that could not be found elsewhere.

The broad objective of this research was to develop a spatial model which provides both timely and quantitative regional maize yield estimates for real-time Early Warning Systems (EWS) by integrating satellite data with groundbased ancillary data. The Food and Agriculture Organization (FAO) Crop Specific Water Balance (CSWB) model was modified by using the real-time spatial data that include: dekad (ten-day) estimated rainfall (RFE) and Normalized Difference Vegetation Index (NDVI) composites derived from the METEOSAT and NOAA-AVHRR satellites, respectively; ground-based dekad potential evapo-transpiration (PET) data and seasonal estimated area-planted data provided by the Government of Kenya (GoK). A Geographical Information System (GIS) software was utilized to: drive the crop yield model; manage the spatial and temporal variability of the satellite images; interpolate between ground-based potential evapotranspiration and rainfall measurements; and import ancillary data such as soil maps, administrative boundaries, etc.. In addition, agro-ecological zones, length of growing season, and crop production functions, as defined by the FAO, were utilized to estimate quantitative maize yields. The GIS-based CSWB model was developed for three different resolutions: agro-ecological zone (AEZ) polygons; 7.6-kilometer pixels; and 1.1-kilometer pixels. The model was validated by comparing model production estimates from archived satellite and agro-meteorological data to historical district maize production reports from two Kenya government agencies, the Ministry of Agriculture (MoA) and the Department of Resource Surveys and Remote Sensing (DRSRS). For the AEZ analysis, comparison of model district maize production results and district maize production estimates from the MoA (1989-1997) and the DRSRS (1989-1993) revealed correlation coefficients of 0.94 and 0.93, respectively. The comparison for the 7.6-kilometer analysis showed correlation coefficients of 0.95 and 0.94, respectively. Comparison of results from the 1.1-kilometer model with district maize production data from the MoA (1993-1997) gave a correlation coefficient of 0.94. These results indicate the 7.6-kilometer pixel-by-pixel analysis is the most favorable method. Recommendations to improve the model are finer resolution images for area planted, soil moisture storage, and RFE maps; and measuring the actual length of growing season from a satellite-derived Growing Degree Day product.

Orientadores: João Mauricio Rosario, Francisco Carlos Parquet Bizarria.
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
Made available in DSpace on 2018-08-12T03:58:51Z (GMT). No. of bitstreams: 1 Barbosa_SilvanaAparecida_D.pdf: 3254271 bytes, checksum: dfd0e2d57b3560c893dad3675337cfe9 (MD5) Previous issue date: 2008
Resumo: A tarefa contínua de detecção de mudança de cenários em determinado ambiente pode ocasionar estresse físico e mental para o supervisor. Com o uso da visão computacional associada à automação é possível oferecer recursos para que essa tarefa seja executada de forma automatizada. Neste contexto, este trabalho apresenta uma proposta de arquitetura para um sistema detectar mudanças de cenários por meio da comparação sucessiva de imagens. Esse sistema de visão deverá possibilitar por meio da implementação de um algoritmo, utilizando recursos matemáticos específicos para a aplicação, a detecção de mudança no cenário e o registro das imagens relativas a essa situação. Para validar a referida proposta, com o enfoque na aplicação aeroespacial, é apresentado nesta tese o estudo de caso para aplicação de técnicas de Visão Artificial na Detecção de Mudança de Cenários em Plataforma de Integração de Veículos Espaciais. Esse estudo visa supervisionar áreas destinadas principalmente à integração e aos testes desse veículo espacial. A implementação desse algoritmo utiliza técnicas de processamento de imagens baseada em filtros espaciais, em especial convolução por filtro da média. Os resultados satisfatórios, obtidos nos ensaios práticos realizados em protótipo da Torre Móvel de Integração, indicam que o sistema é adequado para aplicação a qual se destina.
Abstract: The continuous task of detecting changes in scenarios can cause a mental and physical stress on supervisor. The associated use of computational vision and automation provides resources to execute this task in an automated way. This thesis presents an architectural proposal for a system to detect changes in the imaged scenes by comparing images successively. Through the development of algorithm using specific mathematical tools, this vision system detects and record changes in the imaged scenes. Focusing aerospace area to validate this proposal, Artificial Vision Applied in Detection of Change of Scenes, a Study of Case in Platform for Integration of Space Vehicles is presented in this thesis. The purpose of this research is supervising the designed areas for integration and tests of the space vehicle. Image processing techniques based on spatial filters, in particular convolution, are used for algorithm development. The results obtained through practical tests executed on a prototype of an Integration Mobile Tower, show the system is appropriate to this application.
Doutorado
Mecanica dos Sólidos e Projeto Mecanico
Doutor em Engenharia Mecânica

The CanX-4/-5 mission currently under development at the Space Flight Laboratory will demonstrate sub-metre formation control in four separate formations consisting of two nanosatellites. Formation maintenance is performed using a propulsion payload providing one axis of thrust, resulting in frequent slewing to meet thrust targets. Navigation is GPS dependent, with both satellites equipped with a receiver and antenna pair. Presented is a mission simulation developed for evaluating formation flying algorithm performance and the effects of frequent slewing on GPS coverage. CanX-4 and CanX-5 will be joined for commissioning prior to commencing formation flying via a mechanism, the Intersatellite Separation System. Details regarding the performance testing and troubleshooting of the system are described. Integration and testing of CanX-4/-5 flight hardware into a functional “FlatSat” is presented. Additionally, a description of satellite operations for two nanosatellites is given, with an emphasis on the relevance to the work performed for the CanX-4/-5 mission.

This thesis presents the design of a working and testable satellite with particular emphasis on the electrical, mechanical, and thermal modelling and performance issues for the ECOSat project in the framework of the Canadian Satellite Design Competition. In order of importance, based on the design challenges for the satellite structure were the dynamics modelling and analysis, thermal modeling and analysis, and assembly and integration modeling. Both the dynamics and thermal modeling of the satellite were completed using Finite Element Analysis (FEA) in NX with the NASTRAN solver. The dynamic analysis study was performed first since it has the primary design driver for the structure. These frequencies are of concern due to the 90 Hz or greater fundamental frequency requirement for each axis. The dynamic modes of the satellite structure had the largest influence not only on the design of the structure but also its interface to the electronic systems as these had to meet the required testing qualification levels. It was found that the first fundamental frequency appeared near 200 Hz in the XY plane of the structure. The second study performed was on the thermal modeling of the satellite both for extreme operating conditions in “Hot” and “Cold” cases. Operational limiting cases were identified for the batteries in the cold and hot case study, and the power amplifier for the transmitter was identified for the hot case study. For the batteries to perform satisfactorily for the cold and hot case problem, a metal bracket with an electric heater was added to the design. The heaters were added to the design as a resistive heating element, the additional thermal coupling from the bracket improved heat transfer during the hot case. A trade study analysis was conducted for the power amplifier. Here, a bi directional heat spreader made of pyrolytic graphite attached to a frame member with high thermal inertia was chosen as the optimal solution. Finally, the third study performed tested the interface and clearance requirements of the satellite. The synergistic integration of the electrical and mechanical systems required significant attention in order to ensure the successful assembly, integration, and testing of the two systems. The investigation focused on the cabling assemblies of the satellite. Several design iterations were required for the power regulation, transmitter, receiver, modem, and onboard computer systems. Detailed assembly drawings were created for the cabling assembly fabrication prior to the final integration of the electrical and mechanical systems. The performance simulations show that the satellite systems meet or exceed the required launch qualification tests as well as the thermal cycling requirements for all systems and their components to operate within the manufacturer specified values. Once completely assembled and launched into orbit, the satellite should be able to perform and within its operational and mission requirements in both a sun synchronous or polar orbit at a range of altitudes.
Graduate
0538
0544
0548
jtcurran@uvic.ca

碩士
國立成功大學
測量工程學系
85
In this study Lie series integration method is applied to solveequations of artificial Earth*s satellite orbital motions. The equations of motions are described in the Cartesian coordinates 、u parameters and KS elements , respectively. Different orbitalmotions effected by distinct perturbations are investigated. It is shown that the solutions of equations of motions described in u parameters or KS elements are superior to those of equations of motions described in Cartesian coordinates , especially for highly eccentric orbital motions . The terrestrial gravitational potential and the atmospheric drag are taken into consideration in this thesis . The perturbations caused by the terrestrial gravitation are expanded by the recursive method. The terrestrial gravitational potential model used in the study is OSU91a. The Jacchia 1977 atmospheric density model is used in studying the effects of the atmospheric drag on satellite motions . In the integration process , integration step sizes may be changed according to the Groebner model. Results show that the initial step size can increase rapidly to a reasonable value with the help of a smaller - value ,when it is too small . If the initial step size is too large ,it can be also fast modified to a suitable value by the Groebner model .The calculation efficiency with regard to the orders of the Lie series and different orbital motions is analyzed , too.

Submitted to the Information Technology (IT) Department in conformity with the requirements for the degree of Doctor of Philosophy in Information Technology, Durban University of Technology. Durban, South Africa, 2016.
This doctoral research introduces an integration of satellite systems and new stratospheric platforms for weather observation, imaging and transfer of meteorological data to the ground infrastructures. Terrestrial configuration and satellite communication subsystems represent well-established technologies that have been involved in global satellite sensing and weather observation area for years. However, in recent times, a new alternative has emerged based on quasi-stationary aerial platforms located in the Stratosphere called High Altitude Platform (HAP) or Stratospheric Communication Platforms (SCP). The SCP systems seem to represent a dream come true for communication engineers since they preserve most of the advantages of both terrestrial and satellite communication systems. Today, SCP systems are able to help, in a more cost effective way, developments of space Earth sensing and weather observation and weather sensing and observation. This new system can provide a number of forms ranging from a low altitude tethered balloon to a high altitude (18 – 25 km) fuel-powered piloted aircraft, solar-powered unmanned airplanes and solar-powered airship.

碩士
國立臺灣海洋大學
電機工程學系
97
As a result of the maturity and vigorous development of microelectronic technology, the microminiaturization of satellite system becomes the most important topic in development of the new generation of satellites. The using of small sized, moduled, and high efficient communication modules has become the basic requirement of micro-satellite systems. In this thesis, we designed and integrated the communication module based on the requests of the TUUSAT-1 micro-satellite communication sub-system. Besides, a low cost ground station of TUUSAT-1 was built to provide the operation, control, and data download of micro-satellite. In this thesis, two wireless communication modules were proposed. The first design is based on old-style analog communication system, which uses dual band handheld amateur transceiver and PK-96 packet controller. In order to reduce the cost, the volume, the weight, and the time of development, the second design is based on modifying the industrial low power short distance wireless data transmission module, such that it could be applied in satellite communication. By using the UHF/VHF wireless transceiver chip of Analog Device ADF702X series and the UHF power amplifier chip of Hittite Corp., the communication module is integrated and applied in TUUSAT-1 micro-satellite system successfully. The verification of communication performance was made via link budget, and the data transmission, telemetry, and control from ground station. According to the analysis data, comparisons between the two communication modules proposed in this thesis were presented.

碩士
中華大學
機械與航太工程研究所
91
Abstract In this thesis, both EigenStructure Assignment (ESA) and Linear Exponential Quadratic Gaussian and Loop Transfer Recovery (LEQG/LTR) techniques are unified and applied for the design of a spinning type satellite with Double Gimbals Single Rotor-Control Moment Gyro (DGSR-CMG). For a multivariable system, the response is characterized by both eigenvalues and eigenvector. In addition, the optimal control gain obtained by the LEQG/LTR method can take the covariance of both system and measurement noises into consideration, the proposed method is more robust. By the combination of both ESA and LEQG/LTR control design methods, the control system can simultaneously provide prescribed stability and optimal performance. This paper also derives the algorithms that can take all the time domain, frequency domain, and robust decoupling design techniques into a unified method. Finally, numerical results will show that the proposed method is more robust to disturbance, sensor noise, and parameter variations. In addition, the time domain responses are also better. Keywords: EigenStructure Assignment, Linear Exponential Quadratic Gaussian, Loop Transfer Recovery