Space-borne application of GNSS reflectometry for global sea state monitoring

This research focuses on modelling the relationship between wind conditions, sea roughness and GNSS reflections received from Low Earth Orbit (LEO). The motivation for this study lies in the recent development of a GNSS reflections receiver platform for the UK-DMC satellite and the numerous advantages proposed GNSS Reflectometry can provide in Earth Observation and global disaster monitoring. The fIrst part of the thesis focuses on the simulation procedure of received GPS-R Delay-Doppler Map (DDM). Airborne GPS-R scatterometric model has been adapted into this space-borne application research. Aft~r deriving DDM simulations according to reflection scenario, the results of two-dimensional data-model fItting are presented and analysed. The sensitivity discussion of current GPS-R model suggests some limitations of the modelling method, especially under medium and high wind speed ranges. In the second part, we investigate the inversion scheme of DDMs for the purpose of extracting a statistical wave model empirically. The similar model structure of DDM simulation is used but the processing order is turned over. After deconvolution, DDMs are inversed back to spatial energy maps and spatial slope probability maps. Three inversion algorithms are developed and compared. Preliminary synthetic and real data experiments give evidence of the feasibility of the inversion methodology. Finally, in the third part of this research, a new geometric wave slope statistical model is discussed in the context of wave fIeld simulations. The sensitivity of obtained statistical model is discussed in terms of wind speed, wave direction and observing incident angle. This provides an alternative view point to look into the wave slope probability properties and compensate the traditional theoretic and empirical wave modelling methods. Key words: GNSS-Reflectometry, Delay-Doppler Map inversion, wind conditions, sea surface roughness, slope probability density function, statistical wave slope model.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Proceedings of the Third International Mobile Satellite Conference (IMSC 1993)

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial cellular communications services. While the first and second International Mobile Satellite Conferences (IMSC) mostly concentrated on technical advances, this Third IMSC also focuses on the increasing worldwide commercial activities in Mobile Satellite Services. Because of the large service areas provided by such systems, it is important to consider political and regulatory issues in addition to technical and user requirements issues. Topics covered include: the direct broadcast of audio programming from satellites; spacecraft technology; regulatory and policy considerations; advanced system concepts and analysis; propagation; and user requirements and applications

Advances in approximate Bayesian computation and trans-dimensional sampling methodology

Bayesian statistical models continue to grow in complexity, driven in part by a few key factors: the massive computational resources now available to statisticians; the substantial gains made in sampling methodology and algorithms such as Markov chain Monte Carlo (MCMC), trans-dimensional MCMC (TDMCMC), sequential Monte Carlo (SMC), adaptive algorithms and stochastic approximation methods and approximate Bayesian computation (ABC); and development of more realistic models for real world phenomena as demonstrated in this thesis for financial models and telecommunications engineering. Sophisticated statistical models are increasingly proposed for practical solutions to real world problems in order to better capture salient features of increasingly more complex data. With sophistication comes a parallel requirement for more advanced and automated statistical computational methodologies. The key focus of this thesis revolves around innovation related to the following three significant Bayesian research questions. 1. How can one develop practically useful Bayesian models and corresponding computationally efficient sampling methodology, when the likelihood model is intractable? 2. How can one develop methodology in order to automate Markov chain Monte Carlo sampling approaches to efficiently explore the support of a posterior distribution, defined across multiple Bayesian statistical models? 3. How can these sophisticated Bayesian modelling frameworks and sampling methodologies be utilized to solve practically relevant and important problems in the research fields of financial risk modeling and telecommunications engineering ? This thesis is split into three bodies of work represented in three parts. Each part contains journal papers with novel statistical model and sampling methodological development. The coherent link between each part involves the novel sampling methodologies developed in Part I and utilized in Part II and Part III. Papers contained in each part make progress at addressing the core research questions posed. Part I of this thesis presents generally applicable key statistical sampling methodologies that will be utilized and extended in the subsequent two parts. In particular it presents novel developments in statistical methodology pertaining to likelihood-free or ABC and TDMCMC methodology. The TDMCMC methodology focuses on several aspects of automation in the between model proposal construction, including approximation of the optimal between model proposal kernel via a conditional path sampling density estimator. Then this methodology is explored for several novel Bayesian model selection applications including cointegrated vector autoregressions (CVAR) models and mixture models in which there is an unknown number of mixture components. The second area relates to development of ABC methodology with particular focus on SMC Samplers methodology in an ABC context via Partial Rejection Control (PRC). In addition to novel algorithmic development, key theoretical properties are also studied for the classes of algorithms developed. Then this methodology is developed for a highly challenging practically significant application relating to multivariate Bayesian $\alpha$-stable models. Then Part II focuses on novel statistical model development in the areas of financial risk and non-life insurance claims reserving. In each of the papers in this part the focus is on two aspects: foremost the development of novel statistical models to improve the modeling of risk and insurance; and then the associated problem of how to fit and sample from such statistical models efficiently. In particular novel statistical models are developed for Operational Risk (OpRisk) under a Loss Distributional Approach (LDA) and for claims reserving in Actuarial non-life insurance modelling. In each case the models developed include an additional level of complexity which adds flexibility to the model in order to better capture salient features observed in real data. The consequence of the additional complexity comes at the cost that standard fitting and sampling methodologies are generally not applicable, as a result one is required to develop and apply the methodology from Part I. Part III focuses on novel statistical model development in the area of statistical signal processing for wireless communications engineering. Statistical models will be developed or extended for two general classes of wireless communications problem: the first relates to detection of transmitted symbols and joint channel estimation in Multiple Input Multiple Output (MIMO) systems coupled with Orthogonal Frequency Division Multiplexing (OFDM); the second relates to co-operative wireless communications relay systems in which the key focus is on detection of transmitted symbols. Both these areas will require advanced sampling methodology developed in Part I to find solutions to these real world engineering problems

Ocean Remote Sensing with Synthetic Aperture Radar

The ocean covers approximately 71% of the Earth’s surface, 90% of the biosphere and contains 97% of Earth’s water. The Synthetic Aperture Radar (SAR) can image the ocean surface in all weather conditions and day or night. SAR remote sensing on ocean and coastal monitoring has become a research hotspot in geoscience and remote sensing. This book—Progress in SAR Oceanography—provides an update of the current state of the science on ocean remote sensing with SAR. Overall, the book presents a variety of marine applications, such as, oceanic surface and internal waves, wind, bathymetry, oil spill, coastline and intertidal zone classification, ship and other man-made objects’ detection, as well as remotely sensed data assimilation. The book is aimed at a wide audience, ranging from graduate students, university teachers and working scientists to policy makers and managers. Efforts have been made to highlight general principles as well as the state-of-the-art technologies in the field of SAR Oceanography

Statistical methods for sparse functional object data: elastic curves, shapes and densities

Many applications naturally yield data that can be viewed as elements in non-linear spaces. Consequently, there is a need for non-standard statistical methods capable of handling such data. The work presented here deals with the analysis of data in complex spaces derived from functional L2-spaces as quotient spaces (or subsets of such spaces). These data types include elastic curves represented as d-dimensional functions modulo re-parametrization, planar shapes represented as 2-dimensional functions modulo rotation, scaling and translation, and elastic planar shapes combining all of these invariances. Moreover, also probability densities can be thought of as non-negative functions modulo scaling. Since these functional object data spaces lack a natural Hilbert space structure, this work proposes specialized methods that integrate techniques from functional data analysis with those for metric and manifold data. In particular, but not exclusively, novel regression methods for specific metric quotient spaces are discussed. Special attention is given to handling discrete observations, since in practice curves and shapes are typically observed only as a discrete (often sparse or irregular) set of points. Similarly, density functions are usually not directly observed, but a (small) sample from the corresponding probability distribution is available. Overall, this work comprises six contributions that propose new methods for sparse functional object data and apply them to relevant real-world datasets, predominantly in a biomedical context

Abstracts on Radio Direction Finding (1899 - 1995)

The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography). Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM. The contents of these files are: 1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format]; 2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format]; 3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion

Paleoamerican origins and behavior: a multidisciplinary study of the archaeological record from Lagoa Santa region (east-central Brazil)

By the very end of the Pleistocene the exploratory phase of the settlement of the Americas was over and by the beginning of the Holocene most landscapes were occupied by human populations well-adapted to their local environments. This is a crucial period in the process of cultural and biological differentiation of human groups in the continent and is the focus of the present dissertation. Using multivariate statistics and craniometric data the first two studies presented here investigate the debated hypothesis that those groups were not directly ancestral to recent Amerindians. Results of the first study indicate that during early Holocene the magnitude of morphological variation was not higher than observed among extant populations as was previously proposed. Therefore, in loco differentiation by drift is unlikely to be the major micro-evolutionary agent explaining modern patterns of variation in South America. Results of the second study confirm the century-old hypothesis that the Botocudo Indians (east-central Brazil) have strong morphological affinities with early Holocene groups from Lagoa Santa region constituting a potential case of late survival. The previously reported presence of Polynesian DNA in Botocudo is suggested to reflect the mixing of museum collections. The remaining three studies focus on the early Holocene archaeological record of Lapa do Santo (east-central Brazil) aiming to characterize life style and ritual practices. The third study establishes a formation process model for the site identifying an expressive component of anthropogenic sediments produced after repeated combustion activities accumulating at extremely high rates. The fourth study presents the excavation protocol, chronological Bayesian model and the overall archaeological record with emphasis on the human burials. Accordingly, lithic technology, zooarchaeology, and multi-isotopic analyses indicate foraging groups with low mobility and a subsistence strategy focused on gathering plant foods and hunting small and mid-sized animals. Lapa do Santo was first occupied between 11.7-12.7 cal kyBP and its use as an interment ground started between 10.3-10.6 cal kyBP with primary burials. Between 9.4-9.6 cal kyBP the reduction of the body by means of mutilation, decapitation, defleshing, tooth removal, exposure to fire and possibly cannibalism, followed by the secondary burial of the remains according to strict rules, became a central element in the treatment of the dead. In the absence of monumental architecture or grave goods, these groups were using parts of fresh corpses to elaborate their rituals, showing this practice was not restricted to the Andean region at the beginning of the Holocene as previously thought. Between 8.2-8.6 cal kyBP another change occurred whereby pits were instead filled with disarticulated bones of a single individual without signs of body manipulation. Those changes show that during the early Holocene Lagoa Santa was a region inhabited by dynamic groups that were in constant transformation over a period of centuries. In the fifth study the oldest case of decapitation in the New World is investigated. Confocal microscopy confirms the presence of flake induced cut-marks and strontium isotope analysis indicates the individual was a local member of the group. It is proposed that this decapitation does not reflect punishment or war trophy but instead veneration as part of funerary rituals. In conclusion, this dissertation supports that the groups inhabiting Lagoa Santa during the early Holocene are not the direct ancestral to the majority of the Native Americans. Nevertheless, cases of late survival such as the Botocudo do exist. Future studies based on aDNA will allow testing if these propositions are correct. The archaeological record of Lapa do Santo depicts with unprecedented detail the life of the groups inhabiting east-central Brazil during this period. Sophisticated funerary rituals, high reliance on vegetable items, reduced mobility, dynamic transformations through time, ample cultural diversity and early ethnogenesis are now new hallmarks characterizing those who were among the first to systematically occupy the savannah-like landscapes of east-central Brazil.Im auslaufenden Pleistozän endete die erkundende Phase der Besiedlung Amerikas und zu Beginn des Holozäns wurden die meisten Landschaften von menschlichen Populationen besiedelt, die gut an ihre lokale Umwelt angepasst waren. Dies stellt einen entscheidend wichtigen Zeitraum für den Prozess kultureller und biologischer Differenzierung von Menschengruppen auf diesem Kontinent und den Schwerpunkt der vorliegenden Dissertation dar. Die ersten beiden hier vorgelegten Studien untersuchen durch den Einsatz multivariater Statistik und kraniometrischer Daten die umstrittene Hypothese, dass diese Gruppen nicht die direkten Vorfahren rezenter indigener Völker Amerikas. Die Ergebnisse der ersten Studie weisen darauf hin, dass die Magnitude morphologischer Variation im frühen Holozän nicht höher war als unter bestehenden Populationen beobachtet wurde, wie zuvor vorgeschlagen. Daher erscheint eine in loco Differenzierung durch Drift unwahrscheinlich als mikroevolutionäre Hauptursache um moderne Variationsmuster in Südamerika zu erklären. Die Resultate der zweiten Studie bestätigen die jahrhundertalte Hypothese, dass die Botokuden (Ost-Zentralbrasilien) starke morphologische Ähnlichkeiten mit frühholozänen Gruppen aus der Region Lagoa Santa haben, wodurch ein potenzieller Fall von Spätüberleben konstituiert wird. Es wird darauf hingedeutet, dass das zuvor berichtete Vorkommen polynesischer DNS in Botokuden eine Vermischung von Museumssammlungen wiederspiegelt. Die übrigen drei Studien befassen sich mit den frühholozänen archäologischen Zeugnissen von Lapa do Santo (Ost-Zentralbrasilien) mit dem Ziel die Lebensweise und rituellen Praktiken zu beschreiben. Die dritte Untersuchung erarbeitet ein Modell zur Fundstellengenese um die expressive Komponente der anthropogenen Sedimente, die durch wiederholte, durch extrem hohe Frequenz akkumulierende Verbrennungstätigkeiten fabriziert wurden, zu ermitteln. Die vierte Studie stellt die Grabungsmethodik, das chronologische Bayes’sche-Model und die archäologische Daten allgemein mit besonderer Hervorhebung der menschlichen Bestattungen vor. Dementsprechend zeigen die Steintechnologie, die Zooarchäologie und die Multiisotopenanalysen an, dass es sich um Jäger- und Sammlergruppen mit geringer Mobilität und einer Subsistenzstrategie, die auf dem Sammeln pflanzlicher Nahrung und dem Jagen kleiner und mittelgroßer Tiere beruht, handelt. Lapa do Santo wurde zuerst zwischen 11.7-12.7 ka kal. BP besiedelt und die Nutzung als Bestattungsgelände begann zwischen 10.3-10.6 ka kal. BP mit den Primärbestattungen. Zwischen 9.4-9.6 ka kal. BP wurde die Reduzierung des Körpers mittels Verstümmelung, Dekapitation, Dekarnation, Zahnentfernung, Feuereinwirkung und möglicherweise Kannibalismus, gefolgt von der Sekundärbestattung der Überreste gemäß strikter Regeln, ein zentrales Element in der Totenbehandlung. Diese Gruppen nutzten mangels monumentaler Architektur oder Grabbeigaben Teile der frischen Leichen um ihre Rituale sorgfältig auszuführen, womit belegt wird, dass diese Vorgehensweise am Beginn des Holozäns nicht auf die Andenregion beschränkt ist, wie zuvor angenommen wurde. Zwischen 8.2-8.6 ka kal. BP trat eine andere Veränderung auf, wobei stattdessen Gruben mit disartikulierten Knochen von einzelnen Individuen ohne Anzeichen auf Körpermanipulation gefüllt wurden. Diese Änderungen deuten darauf hin, dass während des frühen Holozäns Lagoa Santa eine Region darstellt, die von dynamischen Gruppen, die in konstantem Wandel über einen Zeitraum von Jahrhunderten war, bevölkert wurde. In der fünften Studie wird der älteste Beleg für eine Dekapitation in der Neuen Welt untersucht. Konfokale Mikroskopie bestätigt die Präsenz von durch Abschläge verursachte Schnittspuren und Strontiumisotopenanalyse weist darauf hin, dass das Individuum ein lokales Mitglied der Gruppe war. Es wird davon ausgegangen, dass die Enthauptung keine Bestrafung wiederspiegelt oder eine Trophäe war, sondern stattdessen Verehrung als Teil des Totenrituals. Zusammenfassend untermauert diese Dissertation, dass die Gruppen, die Lagoa Santa während des frühen Holozäns besiedelten, nicht die direkten Vorfahren der Mehrheit der indigenen Völker Amerikas sind. Dennoch existieren Fälle, die ein Spätüberleben belegen, wie die Botokuden. Zukünftige auf alter DNS basierend Untersuchungen werden es ermöglichen zu testen, ob diese Aussagen korrekt sind. Die archäologischen Zeugnisse von Lapa do Santo beschreiben mit beispielloser Detailliertheit das Leben der in diesem Zeitraum in Ost-Zentralbrasilien lebenden Gruppen. Komplexe Bestattungsriten, ausgeprägte Abhängigkeit von pflanzlichen Produkten, reduzierte Mobilität, dynamischer Wandel durch die Zeit hindurch, reichliche kulturelle Diversität und frühe Ethnogenese sind nun neue Merkmale, die diejenigen charakterisieren, die unter den ersten waren, welche systematisch die savannengleiche Landschaft von Ost-Zentralbrasilien besiedelte

Rural Health

Rural health is the study of healthcare systems in rural settings. This book presents a comprehensive overview of rural health care and addresses such topics as human resources, maternal mortality in developing countries, safety of healthcare workers, zoonotic and veterinary diseases, and much more. Chapters include case studies and research in the field of rural health