Calibration Validation and Polarimetry in 2D Aperture Synthesis. Application to MIRAS

摘要: EnglishLa missio SMOS de l'Agencia Europea l'Espai (ESA) te com a objectiu mesurar la humitat del sol i salinitat dels oceans, parametres fonamentals per tal d'entendre el canvi climatic global. MIRAS (Radiometre microones generador d'imatges pel metode sintesi d'obertura) es un tipus d'instrument nou l'observacio terra l'unic instrument SMOS. Consisteix en agrupacio aprimada (thinned array) forma d'i grega amb 21 elements brac. Amb aquesta tecnica s'aconsegueixen grans obertures sintetiques una massa relativament reduida. Aquesta nova tecnologia ha estat triada SMOS, d'acomplir els criteris resolucio espacial (30-50km) temps revisita (3 dies). En camp radioastronomia ja fan servir instruments similars MIRAS, pero aquest cas les fonts observades tenen mida angular reduida (estrelles galaxies). font extensa que cobreix practicament tot visio manera tecniques calibracio desenvolupades no son valides tesi concentra principalment comprovar experimentalment diferents demostrar capacitat generar imatges. La segona part esta dedicada al mode polarimetric d'aquest millorar rendiment MIRAS. Aquest va iniciar l'any 2000 gracies beca dos anys (de l'estiu 2002) centre ESTEC als Paisos Baixos. Durant estada van realitzar primeres campanyes mesura metodes capacitats imatge aquests tests validacio d'imatge utilitzar primer prototipus realitzacio, planificacio, preparacio, execucio processament dades d'aquesta tesi. Aquelles indicant, mes quina direccio calia continuar treballant refinar-los. Tambe imatges,mitjancant seva resposta impulsional. se'n presenten resultats importants. l'estada tambe treball teoric simulacions sobre interferometria polarimetrica, contribuint formulacio funcio visibilitat polarimetrica definicio funcionament Laboratori Tecnologia Espacial (LST) Universitat Tecnologica Helsinki (HUT) durant tres mesos (agost 2002 octubre investigador convidat. Els coneixements adquirits previament contribuir desenvolupament HUT-2D, radiometre interferometric aerotransportat LST pensat demostrador emprada confirmant obtinguts previes ESTEC. El febrer 2003 l'Institut d'Estudis Espacials Catalunya (IEEC) contracte recerca ministeri d'Educacio Ciencia. Es estudiar l'efecte dela rotacio Faraday resultat proposta solucio compensar-la fent tram final s'ha fet l'electronica control (EGSE) d'un (SAM), l'ESA. permet fer us injeccio soroll dues temperatures, refinament anteriors presenta experimentals preliminars calibracio. ------------------------------------------------------------------------------------------------------------------------- EnglishThe mission of the European Space Agency (scheduled 2007) is devoted to measure Soil Moisture and Ocean Salinity, which are key parameters on understanding global climate change. The single this (Microwave Imaging Radiometer using Aperture Synthesis), new kind Earth observation. It thinned Y-shaped array with arm. With technique large synthetic aperture antenna relative low weight can be obtained. This novel has been selected for in order fulfil both criteria ground resolution (35-50km) revisit time days). Similar have already used radio astronomy but that case only sources narrow size (stars galaxies) were observed. In an extended source thermal radiation, almost fills up complete field view consequence it calibration techniques developed may not mission. thesis mainly focused experimentally test several prove imaging properties A second its capability improve performance. was started thanks two year grant (from summer at Netherlands. During first experimental campaigns aimed methods capabilities done. these so called image validation prototype used. planning, preparation, execution data processing different demonstrated, showing also direction further research should undertaken refine them. demonstrated measurement impulsional response. most important results presented here. At theoretical work simulations interferometry contributed formulation visibility function definition operation After years stage ESTEC, continued Laboratory Technology University three months (August October 2002), as invited researcher. There HUT-2D radiometer, airborne demonstrator being constructed. experience gained previous shared team tested instrument, confirming results. February Institut under contract Spanish ministry research. effect rotation studied. solution compensating proposed, making use polarimteric IEEC, designing manufacturing Electrical Ground Support Equipment known SAM (Small Airborne MIRAS). done ESA. implements scheme two-level noise injection, arefinement schemes prototypes. Preliminary thesis.