La mission spatiale Euclid a pour but d'apporter des réponses quant à la nature de l'accélération de l'expansion de l'Univers. Afin de déterminer les propriétés de cette accélération, la mission spatiale Euclid va effectuer un relevé de galaxies sur 15 000 deg² de champ en imagerie (instrument VIS) et en spectroscopie (instrument NISP) qui requiert un contrôle des précisions instrumentales, notamment sur le système de détection. L'étude faite pendant la thèse se résume en plusieurs étapes: la première étant d'évaluer les performances du NISP à partir de la définition du rapport signal sur bruit et d'en tirer des spécifications sur le système de détection. La seconde consiste en l'étude du besoin de la caractérisation du système de détection de l'instrument, les détecteurs H2RG. À partir de cette étude, on montrera les performances d'un détecteur sur un banc de test. La troisième étape consiste en l'étude de la détection de rayons cosmiques en vol ainsi que la réalisation d'un outil pour isoler les pixels impactés lors du traitement de données au sol. Après avoir évalué les performances de l'algorithme, on montrera les résultats de l'analyse de données. La dernière partie est l'étude de l'effet de persistance affectant les détecteurs H2RG: à partir de l'impact de ce signal sur les observations du NISP, on définira le besoin de mesures de cet effet. On décrira la campagne de prise de données, accompagnée de leur analyse et de l'interprétation physique de la persistance. Ces analyses permettant de comprendre les problématiques de l'effet de persistance et ont servi à l'élaboration d'une modélisation de cet effet pour estimer quantitativement l'impact sur la mission Euclid. / The Euclid space mission aims to provide answers about the nature of the accelerating expansion of the Universe. To determine the properties of this acceleration, the Euclid space mission will conduct a survey of galaxies on a field of 15,000 deg² field of view. Each field will be studied through imaging (VIS instrument) and spectroscopy (NISP instrument) that requires control of instrumental errors, and particularly the detection system. The study made for the thesis can be summarized in several stages: the first is to assess the performance of NISP starting from the definition of the signal to noise ratio and to derive specifications on the detection system. The second is the study of the need for characterization of the detection system of the instrument, the H2RG infrared detectors. From this study, we show the performance of a detector on a dedicated test bench. The third step is the study of the detection of cosmic rays in flight as well as the realization of a tool to isolate the pixels affected using ground data processing. After evaluating the performance of the algorithm, we will show the results of the data analysis. The last part is the study of the persistence effect affecting H2RG detectors: from the impact of the signal on the observations of NISP, we will define the necessary measures for this purpose. We will describe the data acquisition campaign, accompanied by the analysis and physical interpretation of persistence. These analyzes helped to understand the issues of the persistence effect and were used to develop a model of the effect to quantitatively estimate the impact on the Euclid mission.

Euclid is a medium class mission designed to study the geometry of dark universe. It will work in the visible and near infrared imaging & spectroscopy for a lifetime of 6 years down to the magnitude of mAB = 24.5 with Visible Imager Instrument (VIS) and mAB = 24 with Near Infrared Spectrometer and Photometer instrument in Y, J & H broadband filters. The current survey design will avoid ecliptic latitudes below 15 degrees, but the observation pattern in repeated sequences of four blocks with four broad-band filter seems well-adapted to Solar System object detection. The aim of this thesis is to simulate the Solar System Objects (SSOs) for Near Infrared Spectrometer and Photometer (NISP) instrument and measure the flux/magnitude & position of these moving objects. The simulation of Solar System Objects is implemented in with simulator Imagem using the sky position, velocity, direction of movement and magnitude with respect to band of the objects. The length of the trail is determined using exposure time and after that the sky position is evolved for each band filter. The output images showed the trail of objects which is 2 to 10 pixels long in case of Near Infrared Spectrometer and Photometer instrument. To find out the flux distribution in the trail, the differential photometry is performed. The variation in magnitude was observed at least of 1% to 3% of the magnitude which may also implies that variation in brightness of objects can be observed with the velocity. To detect the moving objects, differential astrometry is also performed, which provides the catalogue with the information of position and proper motion of the objects as well as an image is also generated which showed the detected and undetected objects from all bands in one image.

Focussing on Archaeozoological faunal analysis, this dissertation aims to investigate the animal food utilization practices of the Ndzundza Ndebele by combining archaeozoologcial methods, archaeological data, ethnographic and historic information. The Ndzundza Ndebele inhabited three different sites in the Steelpoort River Valley during c. 1700 AD – 1900 AD. They were forced to relocate from KwaMaza and Esikhunjini to KoNomtjarhelo as a result of continual fighting between themselves and contemporary Iron Age/Historic communities, the British and the Boers during this period. I aim to identify the animal species utilized by the Ndzundza Ndebele in addition to whether or not the hostile and politically unstable period had any effect on Ndzundza animal food procurement, use and discard. Additionally I investigate whether the faunal remains recovered from the three sites can be used to identify ethnic affiliations, gender roles and ritual use with regards to animals and/or animal parts. Ultimately, I aim to demonstrate that faunal remains cannot be fully understood and interpreted without incorporating relevant ethnographic and/or historic information and as comprehensive an archaeological context as possible. Copyright / Dissertation (MA)--University of Pretoria, 2009. / Anthropology and Archaeology / unrestricted

Culture types in Pacific Northwest archaeology are characteristic artifact assemblages distinguishing different prehistoric periods. Assemblages indicate a culture type transition during the 2,630 BP–270 BP occupation of Willows Beach (DcRt-10), southeastern Vancouver Island. Faunal remains could reveal links to subsistence patterns, following Croes’s theory that culture type change reflects subsistence intensification. Five dated DcRt-10 faunal assemblages underwent taxonomic and size classification, weighing and MNI calculation. Vertebrate weight and NISP percentages were compared between stratigraphic units associated with the later Gulf of Georgia and earlier Locarno Beach culture types. The youngest assemblage contains a smaller proportion of land mammal bone, suggesting increased sea mammal, fish, and bird procurement. Faunal remains also suggest a greater variety of taxa exploited over time. Faunal assemblages suggest that culture type change at DcRt-10 is the product of subsistence change, increasing knowledge of the culture historic sequence of this region.