Um algoritmo empírico regional para estimativa de clorofila-a na plataforma continental adjacente à Baixada Santista foi desenvolvido a partir de dados radiométricos e de concentração de clorofila-a, obtidos em 49 estações oceanográficas durante dois cruzeiros, em outubro de 2005 e março de 2006. Foram selecionadas aleatoriamente 32 estações para o desenvolvimento do algoritmo e 17 para avaliação do desempenho de modo a representar todos os intervalos de concentração de Cl-a nos dois subconjuntos de dados. O desempenho do algoritmo obtido foi superior (r2 = 0,8424 e EMQ= 0,0418) ao dos algoritmos globais dos sensores SeaWIFS, OC2v4 (r2=0,77; EMQ=0,07), OC4v4 (r2=0,78;EMQ=0,07) e MODIS, OC3 (r2=0,79;EMQ=0,09) para os dados radiométricos, e também superior (r2=0,68; EMQ = 0,028) ao algoritmo global OC3 (r2= 0,62; EMQ= 0,036) para os dados de refletância do sensor MODIS, e apresentou melhor desempenho quanto à influência dos demais componentes bio-ópticos da água nos desvios das estimativas. Com base em dados de dois outros cruzeiros (setembro de 2005 e março de 2006), foi feita uma caracterização oceanográfica da plataforma adjacente à Baixada Santista, que mostrou que a região apresenta acentuada variabilidade sazonal e pode ser caracterizada como oligotrófica em termos de disponibilidade de nutrientes e biomassa fitoplanctônica. / A regional empirical algorithm for chlorophyll-a estimative in the continental shelf adjacent to Baixada Santista was developed based on in situ data on spectral radiometric and chlorophyll-a concentration obtained in 49 oceanographic stations during two oceanographic cruisers, in October 2005 and March 2006. Data from 32 stations were randomly selected for algorithm development and the other 17 for algorithm evaluation, representing all intervals of chlorophyll-a concentration in the two data subset. The performance of the regional algorithm was superior (r2 = 0,8424; RMS = 0,0418) to the global algorithms of the SeaWiFS, OC2v4 (r2=0,77; RMS=0,07), OC4v4 (r2=0,78;RMS=0,07) and MODIS, OC3 (r2=0,79; RMS=0,09) for the radiometric data, and also superior (r2=0,68; RMS = 0,028) to the global algorithm OC3 (r2= 0,62; RMS= 0,036) for reflectance data acquired by MODIS sensor. Also, the regional algorithm presented better performance, while estimative errors, related to the influence of other biooptical components of seawater. Based on the data of two other cruisers (September 2005 and March 2006), the oceanographic characterization of the continental shelf adjacent to Baixada Santista was made, revealing the region presents accentuate seasonal variability and can be characterized as oligotrophic in terms of nutrient availability and phytoplankton biomass.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2008. / Härtill 6 uppsatser. Includes bibliographical references.

Presented is a radiometric sensor and associated electromagnetic propagation models, developed to facilitate non-invasive core body temperature extraction. The system has been designed as a close-proximity sensor to detect thermal emissions radiated from deep-seated tissue 1 cm – 3 cm inside the human body. The sensor is intended for close proximity health monitoring applications, with potential implications for deployment into the improved astronaut liquid cooling garment (LCG). The sensor is developed for high accuracy and resolution. Therefore, certain design issues that distort the close proximity measurement have been identified and resolved. An integrated cavity-backed slot antenna (CBSA) is designed to account for antenna performance degradation, which occurs in the near field of the human body. A mathematical Non-Contact Model (NCM) is subsequently used to correlate the observed brightness temperature to the subsurface temperature, while accounting for artifacts induced by the sensor’s remote positioning from the specimen. In addition a tissue propagation model (TPM) is derived to model incoherent propagation of thermal emissions through the human body, and accounts for dielectric mismatch and losses throughout the intervening tissue layers. The measurement test bed is comprised of layered phantoms configured to mimic the electromagnetic characteristics of a human stomach volume; hence defines the human core model (HCM). A drop in core body temperature is simulated via the HCM, as the sensor monitors the brightness temperature at an offset distance of approximately 7 mm. The data is processes through the NCM and TPM; yielding percent error values < 3%. This study demonstrates that radiometric sensors are indeed capable of subsurface tissue monitoring from the near field of the body. However, the following components are vital to achieving an accurate measurement, and are addressed in this work: 1) the antenna must be designed for optimum functionality in close proximity to biological media; 2) a multilayer phantom model is needed to accurately emulate the point of clinical diagnosis across the tissue depth; 3) certain parameters of the non-contact measurement must be known to a high degree of accuracy; and 4) a tissue propagation model is necessary to account for electromagnetic propagation effects through the stratified tissue.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2008. / Härtill 5 uppsatser.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2008. / Härtill 6 uppsatser.

Diss. (sammanfattning) Umeå : Umeå universitet, 2008. / Härtill 4 uppsatser.

Thesis--University of Oklahoma. / Bibliography: leaves 113-115.

Thesis--University of Oklahoma. / Bibliography: leaves 90-92.

Cette thèse de doctorat traite de la réalisation et la caractérisation métrologique d’un pyromètre à filtre accordable acousto-optique (AOTF). La première partie expérimentale de ce travail a été consacrée à l’étude du fonctionnement et de la caractérisation du filtre AOTF, la seconde, a été dédiée au développement et à l’optimisation du pyromètre AOTF.Contrairement aux pyromètres habituels dont la sélection spectrale est obtenue par un filtre interférentiel, le pyromètre accordable développé dans ce document utilise un filtre acousto-optique adapté à un étalonnage par laser. La longueur d’onde optique de mesure est imposée par la fréquence de l’onde radiofréquence appliquée au filtre acousto-optique, qui ne requiert aucun mouvement mécanique.En contrepartie, le spectre optique diffracté par ce type de filtres, présente d’importants lobes secondaires de diffraction qui dégradent le taux de réjection hors bande du pyromètre. Grace à un montage en double passage dans une configuration optique en œil de chat, les lobes secondaires de diffraction ont été fortement atténués. Le taux de diffusion optique du pyromètre est de l’ordre de 10-5 en valeur relative.La reproductibilité de sa sensibilité spectrale en longueur d’onde est de 0,01 nm et 0,1 % en amplitude sur une semaine. Ces caractéristiques, comparables à celles des meilleurs monochromateurs, permettent l'utilisation du pyromètre AOTF pour des applications métrologiques au meilleur niveau d’exactitude. L'instrument est accordable en longueur d'onde sur un domaine étendu, compris entre 600 nm et 950 nm. Il est également transportable car sa masse est inférieure à 20 kg et sa longueur inférieure à 1 m. Les performances et la caractérisation métrologique du pyromètre ont été validées par la mesure de la température thermodynamique du point du cuivre, en accord avec celle donnée dans l'EIT-90. / This PhD Thesis presents the work that has been done to design and build, along with the evaluation of the radiometric performance, of a radiation pyrometer based on acousto-optic tunable filter (AOTF). Part of this work has been given to the characterization of the acousto-optic tunable filter (AOTF); however, the other part has been dedicated to the development and the optimization of the radiation pyrometer.Unlike conventional pyrometers whose spectral selection is obtained an interference filters, the AOTF that has been used in this work enables direct calibration of the radiation pyrometer using laser sources without any interference effects. This in turns allows direct calibration of the pyrometer against the cryogenic radiometer or through trap detectors with lower uncertainty levels. The spectral range selected by the AOTF is adjusted by changing the frequency applied to the filter without any mechanical movement, which is an advantage compared to grating-based systems.One of the main limitations in using AOTF is the existence of diffraction lobes which appear beyond the in-band spectral range. These lobes result in significant deterioration in the blocking capabilities of the filter, and thus an increased out-of-band signal levels are obtained. However this has been solved by using a double-pass optical configuration, which has reduced these diffraction lobes and kept them within insignificant levels. The resultant out-of-band signal levels have been found within 10-5 of the in-band signal. The reproducibility of wavelength calibration is within 0.01 nm, yet with 0.1 % reproducibility in the amplitude of the in-band signal over a course of one week. The stability of wavelength is comparable to that found in high quality monochromators. This in turns allows the use of our pyrometer in metrological applications that require high level of accuracy. The instrument spectral coverage can be tuned over a wide spectral range, between 600 nm and 950 nm. The pyrometer is also transportable as its mass is less than 20 kg and with dimensions of 90 L x 20 H x 30 W cm. The performance and metrological characterization of the pyrometer have been validated by measuring the thermodynamic temperature of the freezing point of the copper, which was in a very good agreement with that value defined by the International Temperature Scale (ITS-90).

Cette thèse a pour sujet l'étude du régolithe développé sur les massifs ultrabasiques de Nouvelle-Calédonie. Dès l'Oligocène, la Nappe des Péridotites est soumise à l'altération supergène sous climat tropical humide. Le manteau d'altération (régolithe) qui se développe est le siège de phénomènes géologiques dont l'un des plus remarquables estl'enrichissement des teneurs en Ni et Co. Ce régolithe très particulier, que constituent les profils latéritiques sur rochesultrabasiques, a été largement étudié par le passé, surtout pour son intérêt économique. Une synthèse des connaissances a été réalisée. De nombreuses données acquises durant cette thèse permettent de mieux cerner l'évolution minéralogique, géochimique et géologique des profils d'altération. Un apport important sur la connaissance des saprolites fines (oulatérites), peu étudiées, a été réalisé. La cartographie des formations ultrabasiques et de leur manteau d'altération (1/ 50000) s'appuie sur des observations de terrain classiques, et fait appel à la géomorphologie, l'analyse structurale, l'altérologie, l'hydrogéologie, etc. Afin d'améliorer la couverture cartographique sur des zones difficiles d'accès, de nouveaux outils ont été évalués. Le premier outil, la télédetection hyperspectrale, a permis avec succès de cartographier des zones de sols nus, mais aussi de réaliser des cartes minéralogiques ayant un intérêt pour la prospection minière (carte de répartition des oxy-hydroxydes de fer, carte du taux de serpentinisation). La deuxième méthode utilise quant à elle la spectrométrie gamma au sol, pour cartographier le cortège d'intrusif de l'ophiolite. L'âge de formation des manteaux d'altération reste difficile à établir. Le recours à une méthode de datation par paléomagnétisme a permis pour la première fois d' attribuer un âge aux cuirasses sommitales des profil s. Les âges les plus anciens obtenus (25 Ma) montrent que l'altération a débuté dès l'Oligocène supérieur à Thiébaghi et Goro, aux deux extrémités de la Grande Terre, mais qu'elle s'est interrompue à Thiébagi et qu'elle s'est pours uivie jusqu'à la période actuelle dans le Sud du Massif du Sud (Goro). L'étude pétrographique et paléomagnétique des cuirasses des klippes de la côte ouest montrent la difficulté de retrouver des témoins de la surface oligocène sur ces massifs. Les observations géomorphologiques témoignent d'un démantèlement avancé de ces massifs sous l'effet de mouvements verticaux importants. Une vision globale des évènements« post-abduction » peut-être proposée par l'étude complémentaire des (i) sédiments post-abd uction [Népoui principalement) et des (ii) granitoïdes oligocènes. En effet, la découverte récente d'un calcaire d'âge Miocène inférieur sous le conglomérat de Pindaï (Groupe de Népoui) permet de réévaluer précisément l'âge de dépôt de ce conglomérat torrentiel, constitué principalement d'éléments des profils d'altération oligocènes. L'âge obtenu est très proche de de celui du granite de Koum ayant subi une exhumation rapide (données traces de fissions sur apatite). L'ensemble des donnéesconvergent vers une cause tectonique plutôt qu'eustatique pour expliquer les mouvements verticaux importants responsables de la géomorphologie actuelle de la Ride de Norfolk. La rupture de la plaque plongeante, responsable de l'abduction, a permis la mise en place du granitoïde de Koum et le soulèvement de la Ride, à la faveur de l'ouverture d'une fenêtre asthénosphérique permettant la remontée de manteau.Le taux de surrection différent entre le Nord et le Sud de la Grande Terre est responsable de la configuration actuelle des massifs de péridotite. Dans le Nord du Massif duSud, la côte ouest et le Nord, les massifs sont montagneux et les gisements de nickel sont de type silicaté saprolitique (quelques plateaux présentent des latérites). Dans l'extrémité méridionale du Massif du Sud, les paysages sont des bassins et les gisements de nickel sont du type oxydé latéritique. / This work deals with regolith development on ultramafic rocks in New Caledonia. From the Oligocene on, the peridotite Nappe is subject to supergene weathering under wet tropical climate. The weathering mantle (regolith) that develops, led to geological phenomena of which the most remarkable are economie concentrations of Ni and Co. This particular regolith developed on ultramafic rocks, has been extensively studied in the past, especially for its economie interest. A lmowledge synthesis is presented. Data acquired during this work helps identifying the mineralogical, geochemical and geologicalevolution of weathering profiles. An important contribution to the knowledge of the Jess known fine saprolite (or laterite), has been done. Mapping ultramafic units and their weathering mantle (1/50, 000) is based on usual field observations, geomorphology, structural analysis, alterology, hydrogeology, etc. To improve mapping in remote areas, new tools were assessed. The first tool, hyperspectral remote sensing, has been successful used on areas of bare sail, but also to performmineralogical mapping having an interest in mineral exploration (mapping of distribution of iron oxy-hydroxides and of serpentinisation grade). The second method used is the gamma spectrometry to map the late-intrusive dyke network of the ophiolite. The age of formation of the regolith remains difficult to establish. The use of an indirect method by paleomagnetic dating allows for the first time to assign an age to the top-most ferricrete of the weathering profiles. The oldest age obtained (25 Ma) shows that weathering began during Late Oligocene at Thiébaghi and Goro, at both ends of the Grande Terre, butceased at Thiébagi while continuing up to the present period in the south of Massif du Sud (Goro). The paleomagnetic and petrographie study of ferricretes from the West Coast klippen, show the difficulty of finding remnants of the Oligocene surface on these units. Geomorphological observations show evidences of an early dismantling of the regolith onthese units due to large vertical movements. An overview of "post-abduction" events may be proposed by the further study of (i) post-abduction Oligocene sediments (Népoui series) and (ii) Late Oligocene granitoids. The recent discovery of an Early Miocene limestone unit of younger age below the Pindaï conglomerate (Népoui Group) allows to reassess precisely the time of deposition of this torrential conglomerate, consisting mainly of Oligocene regolith elements. Age obtained is very close to that of the Koum granite that has undergone a rapid exhumation (new apatite fission tracks data). A tectonic rather than eustatic cause explains better the large vertical movements responsible for the present geomorphology of the Norfolk Ridge. Slab break off of the overridden plate, responsible for the abduction, allowed the intrusion of Koum granitoid and the uplift of the ridge, du ring the opening of an asthenospheric window. The different rate of uplift between the North and the South of Grande Terre is responsible for the present configuration of peridotite massifs. In the northern part of Massif du Sud, the West Coast and the North of Grande Terre, the ultramafic units are in a mountainous context and nickel deposits are of the saproiite silicate type (a few plateaus have also laterite deposits). In the southern part of Massif du Sud, in a context of basins, nickel deposits are of the oxide lateritic type.