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Resumen La interferometría diferencial con radar de apertura sintética (SAR) es una técnica conocida en teledetección por sus aplicaciones en la generación de modelos digitales del terreno y el monitoreo de deformaciones de la corteza terrestre. Esta técnica se basa en la fase, un parámetro presente en las imágenes SAR y sensible a la topografía del terreno. Las diferencias de fase se relacionan con cambios de elevación ocurridos entre dos barridos del satélite sobre un mismo espacio. Para la obtención de información topográfica se requiere un modelo digital del terreno y la diferencia de fase permite realizar estimaciones de desplazamiento vertical del terreno con precisiones superiores a 1 centímetro. El presente trabajo permitió estimar la deformación superficial experimentada en la ladera oeste del cráter del volcán Turrialba tras la erupción del 1 de agosto de 2020. Para ello se utilizaron varias imágenes captadas por el sensor Sentinel 1A, de la Agencia Espacial Europea. Abstract Differential synthetic aperture radar interferometry (SAR) is a technique known in remote sensing for its applications in the generation of digital terrain models and the monitoring of deformations of the earth’s crust. This technique is based on the phase, a parameter present in SAR images and sensitive to terrain topography. Phase differences are related to elevation changes that occur between two satellite scans over the same space. To obtain topographic information, a digital terrain model is required and thus, phase differences provide information for estimating vertical terrain displacement to an accuracy greater than 1 centimeter. In the present work it was possible to estimate the surface deformation that occurred on the western slope of the crater of the Turrialba volcano after the eruption of August 1, 2020. For this purpose, several images captured by the Sentinel-1A sensor of the European Space Agency were used.

[EN] Sentinel-1 interferometric time-series allow for the accurate retrieval of the target’s temporal decorrelation and, therefore, the inversion of land cover information and its temporal monitoring. This paper describes the development of an observation scenario for monitoring monthly deforestation over the Amazon rainforest, which relies on the use of radar for overcoming the physical limitations of optical sensors caused by the presence of cloud coverage. Specifically, we implement a classification scheme that exploits multi-temporal SAR features, such as backscatter, spatial textures, and interferometric parameters, to map forested areas. Distinct forest maps are generated for consecutive months and further processed to detect deforestation phenomena and map clear-cuts evolution. The obtained results are validated by selecting cloud-free Sentinel-2 multispectral data on the selected area and acquired during the same observation time., [ES] Las series temporales interferométricas Sentinel-1 permiten la estimación precisa de la decorrelación temporal de la muestra y, por tanto, la recuperación de información acerca de la cobertura terrestre y su seguimiento temporal. Este artículo describe el desarrollo de un escenario de observación para el seguimiento de la deforestación mensual sobre la selva amazónica, basándose en el uso de datos radar para superar las limitaciones físicas propias de los sensores ópticos debido a la presencia de cobertura nubosa. En particular, se ha implementado un esquema de clasificación que explota las características multitemporales SAR, como la retrodispersión, texturas espaciales y parámetros interferométricos, para identificar áreas de bosque. Distintos mapas de bosque para meses consecutivos fueron generados y procesados para detectar fenómenos de deforestación y su evolución. Los resultados obtenidos fueron validados a partir de imágenes Sentinel-2 libres de nubes adquiridas sobre la misma zona y hora de observación., The performed work has been partially financed through the HI-FIVE project, granted by the ESA Living Planet Fellowship 2018. The authors gratefully acknowledge the Sentinel-1 mission management, in the person of Luca Martino and Pierre Potin, for providing an additional acquisition scheduling over the state of Rondonia.

Trabajo de Fin de Máster del Máster en Geotecnologías cartográficas en ingeniería y arquitectura, curso..., [ES] La plataforma de tipo radar de apertura sintética o SAR se ha convertido en una tecnología fundamental en la actualidad. Su capacidad de trabajo las 24 horas del día y sin verse afectados por las condiciones meteorológicas de nubosidad o precipitaciones permiten la obtención de imágenes de la superficie terrestre en cualquier momento. A lo largo de este trabajo se utilizan la metodología SAR de las plataformas satelitales Sentinel 1-A y1-B, cuyo modo de operación es muy útil para la monitorización de la superficie terrestre. La línea de transmisión de doble circuito Transchile Charrúa-Cautín, en Chile, permite que multitud de comunas y ciudades tengan energía. Sin embargo, Chile es un país completamente geológico que se ve afectado por multitud de estructuras capaces de producir algún evento que conlleve a generar un riesgo geológico. Por este motivo, es importante poder tener un monitoreo de la zona de estudio y ver cómo elementos o estructuras geológicas pueden afectar a nuestro área de interés. La teledetección permite estudiar estos elementos o estructuras desde el punto de vista satelital a través de imágenes de la superficie terrestre. Cualquier cambio que pueda verse en esas imágenes afectará de manera más o menos directa al terreno y, por tanto, a la zona de estudio. A través del procesamiento de las imágenes con uso de un software especializado se pueden resolver los objetivos propuestos con el fin de obtener unas conclusiones lo más precisas posibles.

El objetivo principal de esta iniciativa es realizar un análisis de subsidencia en la periferia de Bogotá, donde el crecimiento urbano en el tiempo ha aumentado, debido al desplazamiento forzado desde otras regiones de Colombia o incluso desde afuera de esta, lo cual ha sobrecargado el suelo, aumentado las construcciones, cambiando el curso normal de las escorrentías y cambiando sustancialmente la composición del mismo, para lo cual se obtienen mapas de desplazamiento diferenciales que muestran el desplazamiento del subsuelo a través de los años y permite ver su comportamiento originado en el crecimiento urbano que supera la capacidad portante del suelo. The main objective of this initiative is to carry out a subsidence analysis in the periphery of Bogotá, where urban growth over time has increased, due to displacemen forced from other regions of Colombia or even from outside it, which hasoverloaded the ground, increased the constructions, changing the normal course of therunoff and substantially changing its composition, for which we obtain differential displacement maps showing the displacement of the subsurface through over the years and allows us to see its behavior originated in urban growth that exceeds the bearing capacity of the soil.

Carajás Mineral Province, Amazon region, is the most important one in Brazil. Vale S.A. Company has the right to operate in the area of the N5E mine. The work is conducted on rock alteration products of low geomechanical quality related to sandstones, siltstones, and a lateritic cover. In order to monitor ground deformation, 33 TerraSAR-X images covering the period of March 2012-April 2013 were used in the investigation. An interferometric synthetic aperture radar (InSAR) approach based on permanent scatterer interferometry (PSI) using an interferometric point target analysis algorithm was applied. Results demonstrated that most of the area was considered stable during the time span of the image acquisition. However, persistent scatterers (PSs) with high deformation rates were mapped over a landfill probably related to settlements. To validate the PSI data, graphs were generated with the displaced information based on topographic measurements in the field. The graphs showed that the surface deformations during TSX-1 runway coverage are within the miner’s safety threshold and do not present a risk of major problems. The PSI data provided a synoptic and detailed view of the deformation process that affects the mining complex without the need of field campaign or instrumentation.

The aim of Geostationary Synthetic Aperture Radar (GeoSAR) missions is to obtain daily images of events that take place over the Earth's surface. Some of them are critical to monitor (e.g. land stability control, natural risks prevention or accurate numerical weather prediction models from water vapour atmospheric mapping) since their fast evolution is not observable with current Low Earth Orbit (LEO) based systems. Thus, the fixed location of a geostationary satellite with respect to the Earth's surface may be used to permanent monitor the evolution of this kind of events. The term fixed is in quotation marks due to the geostationary satellite does not remain still. Some perturbations such as the forces exerted by the Earth's equatorial bulge, third bodies (e.g. the Moon or the Sun), etc., degrade the geostationary Earth orbit (GEO) enabling the satellite to describe an elliptical movement. Such path can consequently be used to form the Synthetic Aperture needed to obtain the Synthetic Aperture Radar (SAR) images. The recent analysis of GeoSAR missions shows that the range history of every point of the scene during echo acquisitions must be known precisely in order to obtain focused images of the Earth's surface. Therefore, the orbit of the geostationary satellite must be known in an unprecedented precision (cm), which is far from typical repositioning of satellites in GEO orbits. In order to determine the satellite orbit precisely, two systems are presently being under research in GeoSAR missions: a group of Active Radar Calibrators (ARCs), and a ground-based interferometer system. This project will focus on the latter. The ground-based interferometer system makes use of the transmissions of present communication satellites located in GEO orbits to provide interferometric phase observations. Such observations can be used to calculate the satellite orbit with a certain precision. This project will discuss the precision outcome that two differential correction techniques ideally suited for orbit determination offer when using the interferometric phase observations. Such techniques are the Least Squares (LS) technique, and the extended Kalman filters (EKF). The performance of both techniques will be evaluated in different situations in order to obtain a complete overview of their precision outcome. Then, the error results of both techniques will be compared in order to determine the best technique to be used for orbit determination when a ground-based interferometer system is considered. Finally, this project will also address the absolute phase ambiguity resolution. Such issue is of special importance when dealing with interferometer systems since the LS and EKF techniques do not achieve convergence unless the absolute phase cycles of the transmitted signals are taken into account. Thus, the last chapter of this project will be devoted to explain a method to overcome the absolute phase ambiguity.

The final publication is available at link.springer.com via http://dx.doi.org/10.1007/s11432-016-9052-y Future GeoSAR missions are expected to provide higher resolution radar images featuring shorter revisit times by locating a radar payload on-board of a geostationary satellite. One of the main challenges in GeoSAR processing is accurately determining the satellite orbit to obtain a precise phase history, in order to properly focus the retrieved data. To tackle this challenge, a multiple baseline ground-based interferometer is proposed as a compact and reliable method to achieve an unprecedented accuracy. As a proof of concept, this paper presents the results obtained from a single baseline prototype, whose results can be extrapolated to a larger system, able to be used in future missions.

Carajás Mineral Province, Amazon region, is the most important one in Brazil. Vale S.A. Company has the right to operate in the area of the N5E mine. The work is conducted on rock alteration products of low geomechanical quality related to sandstones, siltstones, and a lateritic cover. In order to monitor ground deformation, 33 TerraSAR-X images covering the period of March 2012-April 2013 were used in the investigation. An interferometric synthetic aperture radar (InSAR) approach based on permanent scatterer interferometry (PSI) using an interferometric point target analysis algorithm was applied. Results demonstrated that most of the area was considered stable during the time span of the image acquisition. However, persistent scatterers (PSs) with high deformation rates were mapped over a landfill probably related to settlements. To validate the PSI data, graphs were generated with the displaced information based on topographic measurements in the field. The graphs showed that the surface deformations during TSX-1 runway coverage are within the miner’s safety threshold and do not present a risk of major problems. The PSI data provided a synoptic and detailed view of the deformation process that affects the mining complex without the need of field campaign or instrumentation. RESUMO: A Província Mineral de Carajás, região amazônica, é a mais importante do Brasil. A Vale S.A. tem o direito de operar na área da mina N5E, que é conduzida em produtos de alteração de rochas de baixa qualidade geomecânica relacionados a arenitos, siltitos e uma cobertura laterítica. Para monitorar a deformação do solo, foram utilizadas 33 imagens de TerraSAR-X cobrindo o período de março de 2012 a abril de 2013. Foi aplicada uma abordagem interferométrica de radar de abertura sintética (InSAR) baseada em interferometria de espalhadores persistentes (PSI) utilizando um algoritmo de análise de alvo pontual. Os resultados mostraram que a maior parte da área foi considerada estável durante o período de aquisição de imagens, entretanto os espalhadores persistentes (PSs) com altas taxas de deformação foram mapeados em aterro, provavelmente relacionado a assentamentos. Para validar os dados PSI, foram gerados gráficos com os dados de deslocamento medidos em campo. Os gráficos mostraram que as deformações superficiais durante a cobertura das imagens TSX-1 estão conforme o limiar de segurança do minerador e não apresentam risco de problemas maiores. Os dados PSI forneceram uma visão sinóptica e detalhada do processo de deformação que afeta o complexo de mineração sem a necessidade de campanha de campo ou instrumentação.

La ciudad de Antofagasta, como otras ciudades de las regiones costeras Chilenas, se ha visto afectada por la ocurrencia de diferentes movimientos sísmicos a lo largo de los últimos años, causando con esto diferentes desplazamientos en sus bloques costeros. Por lo tanto, soportado con nuevas tecnologías y metodologías de adquisición remota de información, se han desarrollado diferentes proyectos de investigación en los cuales el uso de imágenes de RADAR permiten la generación de interferogramas que registran los desplazamientos producidos por los sismos de mayor magnitud luego de elaborar un análisis multitemporal. Dicho esto, el presente proyecto contempla la descripción, análisis y presentación de resultados para un proyecto que relacione la implementación de esta tecnología y sus respectivas metodologías. Universidad Distrital Francisco Jose de Caldas Universidad de Antofagasta The Antofagasta city, like other cities of the Chilean coastal regions, has been affected by the occurrence of various earthquakes over the years, causing this different offsets in their coastal blocks. Therefore, compatible with new technologies and methodologies for remote data acquisition, have developed different research projects in which the use of images of RADAR allow generation of interferograms that record the displacements produced by earthquakes of greater magnitude after develop a multi-temporal analysis. That said this project includes the description, analysis and presentation of results for a project that relates the implementation of this technology and their respective methodologies.

The first three of a series of new generation satellites operating at L-band microwave frequencies have been launch in the last decade. L-band is particularly sensitive to the presence of water content in the scene under observation, being considered the optimal bandwidth for measuring the Earth's global surface soil moisture (SM) over land and sea surface salinity (SSS) over oceans. Monitoring these two essential climate variables is needed to further improve our understanding of the Earth's water and energy cycles. Additionally, remote sensing at L-band has been proved useful for monitoring the stability in ice sheets and measuring sea ice thickness. The ESA's Soil Moisture and Ocean Salinity (SMOS, 2009-2017) is the first mission specifically launched to monitor SM and SSS. It carries on-board a novel synthetic aperture radiometer with multi-angular and full-polarization capabilities. NASA's Aquarius (2011-2015) was the second mission, devoted to SSS monitoring with a combined real aperture radiometer/scatterometer system that allows correcting for sea surface roughness. NASA's Soil Moisture Active Passive (SMAP, 2015-2018) is the second mission dedicated to measure SM. It carries on-board a real aperture full-polarimetric radiometer and a synthetic aperture radar (SAR) for enhanced spatial resolution and freeze/thaw detection. This Ph.D. Thesis is focused on analyzing the geophysical information that can be obtained from L-band SMOS, Aquarius and SMAP observations. The research activities are structured as follows: -Inter-comparison of radiometer brightness temperatures at selected targets. A novel methodology to measure the consistency between SMOS and Aquarius radiometric data over the entire dynamic range of observations (land, ice and ocean) is proposed. It allows detecting spatial/temporal differences or biases without latitudinal limitations neither cross-overs. This is a necessary step to combine observations from different instruments in a long term dataset for environmental, meteorological, hydrological or climatological studies. -Ice thickness effects on passive remote sensing of Antarctic continental ice. The relationship between Antarctic ice thickness spatial variations and changes detected by SMOS and Aquarius measurements is explored. The emissivity of Antarctica is analyzed to disentangle the role of the geophysical contributions (snow layers at different depths and subglacial lakes) to the observed signal. The stability of the L-band signal in the East Antarctic Plateau, calibration/validation site for microwave satellite missions, is assessed. -Microwave/optical synergy for multi-scale soil moisture sensing. The relationship of SM and land surface temperature (LST) dynamics is evaluated to better understand the fundamental SM-LST link through evapotranspiration and thermal inertia physical processes. A new approach to measure the critical soil moisture from time-series of spaceborne SM and LST is proposed. The synergistic use of SMOS SM and remotely sensed LST for refining SM disaggregation algorithms is also analyzed. -Comparison of passive and active microwave vegetation parameters. Recent research has shown that microwave vegetation opacity, sensitive to biomass and water content, and albedo, related to canopy structure, can be retrieved from passive L-band observations. The relationships between these two parameters and radar-derived vegetation descriptors have been explored using airborne observations from the SMAP Validation Experiment 2012 (SMAPVEX12). The obtained relations could allow for improved SM retrievals in active-passive systems, and also to estimate the vegetation properties at high resolution using SAR observations. The Ph.D. Thesis has been developed within the activities of the Barcelona Expert Centre (BEC). The presented results contribute to the use of L-band remote sensing in different scientific disciplines such as climate, cryosphere, hydrology and ecology., Els primers tres d'una sèrie de satèl·lits de nova generació funcionant a la banda L han sigut llançats a l'última dècada. La banda L es molt sensible a la presència d'aigua a l'escena observada, sent considerada òptima per mesurar la humitat del sòl (SM) i la salinitat del mar (SSS) de manera global a la superfície de la Terra. Monitoritzar aquestes dues variables climàtiques essencials es necessari per millorar el nostre coneixement dels cicles de l'aigua i l'energia. La teledetecció a banda L també ha sigut útil per monitoritzar l'estabilitat de les capes de gel i mesurar el gruix de gel marí. La missió Soil Moisture and Ocean Salinity (SMOS, 2009-2017) de l'ESA és la primera específicament llançada per monitoritzar SM i SSS. Porta un nou radiòmetre d'apertura sintètica amb capacitat multiangular i polarització completa. La missió Aquarius (2011-2015) de la NASA va ser la segona, dedicada a monitoritzar SSS amb un sistema de radiòmetre/escateròmetre d’apertura real que permet corregir la rugositat de la superfície del mar. La missió Soil Moisture Active Passive (SMAP, 2015-2018) de la NASA és la segona dedicada a mesurar SM. Porta un radiòmetre d'apertura real i polarització completa i un radar d'apertura sintètica (SAR) per una millor resolució espaial i detecció de congelació/descongelació. Aquesta tesi està enfocada en analitzar la informació geofísica que pot obtenir-se de les observacions a banda L d'SMOS, Aquarius i SMAP. La seva investigació està estructurada com: -Intercomparació de temperatures de brillantor en zones seleccionades. Es proposa un nou mètode per mesurar la consistència entre les dades radiomètriques d'SMOS i Aquarius sobre el rang dinàmic complet d'observacions (terra, gel, oceà). Això permet detectar diferències espaials/temporals o biaixos sense limitacions latitudinals ni creuaments. Aquest pas es necessari per combinar observacions de diferents instruments en un llarg conjunt de dades per estudis mediambientals, hidrològics o climatològics. -Efecte de gruix de gel en teledetecció de gel continental a l'Antàrtida. S'explora la relació entre les variacions espaials del gruix de gel antàrtic i els canvis detectats a les mesures d'SMOS i Aquarius. L'emissivitat de l'Antàrtida es analitzada per discernir el rol de les contribucions geofísiques (capes de gel a diferents profunditats i llacs subglacials) al senyal observat. S'avalua l'estabilitat del senyal a banda L sobre la zona est de l'altiplà antàrtic, lloc per calibratge/validació de satèl·lits de microones. -Sinèrgia de microones/òptic per teledetecció de SM multiescala. S'avalua la correlació entre la SM i la temperatura de la superfície del sòl (LST) per entendre millor la relació SM-LST a través de processos físics d'evapotranspiració i inèrcia tèrmica. Es proposa un nou mètode per mesurar la humitat crítica utilitzant sèries temporals de SM i LST de satèl·lit. S'analitza l'ús de la SM de SMOS amb la LST de teledetecció per refinar algorismes de desagregació de SM. -Comparació de paràmetres passius i actius de microones relatius a la vegetació. Recent investigació ha mostrat que l'opacitat, sensible a la biomassa i el contingut d'aigua, i l'albedo, relacionat amb l'estructura, poden ser recuperats d'observacions passives a banda L. S'exploren les relacions entre aquests dos paràmetres i estimadors de vegetació derivats de radar utilitzant les observacions d'avió de l'experiment de validació d'SMAP 2012 (SMAPVEX12). Les relacions obtingudes podrien permetre millors recuperacions de SM en sistemes actius/passius i estimar les propietats de la vegetació a alta resolució utilitzant mesures de SAR. La tesi s'ha desenvolupat dins les activitats del Barcelona Expert Centre (BEC). Els resultats presentats contribueixen a l'ús de la banda L a diferents disciplines científiques com la climatologia, la criosfera, la hidrologia i l'ecologia.

Future geostationary radar systems will require the satellite orbit modeling with precisions in the order of the radar wavelength. Using interferometric techniques it is possible to determine satellite angular observables along time which can be used for precise orbit determination. The development of a first compact interferometer has been proposed as a proof of concept. En el futuro, los radares geostacionarios requeriran de un modelage orbital conuna precisión en el orden de la longitud de onda usada. Utilitzando tècnicas interferométriques podemos obtener observables orbitales de alta precisión que pueden ser usados para determinación orbital. Este proyecto sirve como a demostración experimental de este concepto. En el futur, els radars geostacionaris requeriran d'un modelatge orbital amb una precisió en l'ordre de la longitud d'ona utilitzada. Utilitzant tècniques interferomètriques podem obtenir observables orbitals d'alta precisió que poden ser usats per a determinació orbital. Aquest projecte serveix com a demostració experimental d'aquest concepte.

El acuífero terciario detrítico de Madrid (ATDM) refuerza el suministro de agua a parte de la Comunidad Autónoma de Madrid, incluyendo Madrid, la ciudad más poblada de España (3.2 millones de habitantes en el área metropolitana). Entre 1992 y 2011 el acuífero experimentó cinco ciclos de extracción asociados a varios periodos de sequía. En este trabajo se analiza la deformación del terreno producida por la extracción de agua y su posterior recuperación utilizando para ello la técnica de interferometría de radar (InSAR). Para ello se han analizado series temporales InSAR y datos piezométricos en 19 pozos de extracción durante el periodo 1997-2010. La correlación entre la deformación del terreno y la piezometría en los pozos analizados es superior al 85%, siendo pues posible modelizar esta relación asumiendo un comportamiento elástico del acuífero. Para construir los modelos elásticos, primero se estima el coeficiente de almacenamiento elástico (Ske) para cada pozo, que muestra un gradiente N-S correlacionado con un cambio litológico gradual en el acuífero. Este coeficiente es utilizado después para predecir la deformación del terreno y el nivel piezométrico en cada pozo durante el periodo de estudio. Por último, se discute la posibilidad de extender este análisis a todo el ATDM para crear mapas piezométricos y estimar variaciones en el volumen de agua almacenada en el acuífero.

O objetivo deste trabalho foi estabelecer as relações entre os parâmetros dendométricos de florestas e a resposta da radiometria e da interferometria obtidas por sensores SAR (Synthetic Aperture Radar), utilizando técnicas de regressão multivariada. Uma área de povoamento de Eucalyptus grandis, com 6,1 anos de plantio, foi selecionada para estudo. Os resultados indicaram que o volume das parcelas foi altamente correlacionado com o logaritmo da altura interferométrica (LogHint) obtida pela diferença entre os modelos interferométricos nas bandas X e P, enquanto que o DAP (Diâmetro à Altura do Peito) apresentou melhor relação com a combinação da coerência interferométrica na banda PVV (CohPVV) e o LogHint. A altura comercial da vegetação, similarmente ao DAP, foi melhor explicada com a combinação da CohPvv e o LogHint. Os resultados obtidos demonstraram que, devido ao povoamento ser constituído de indivíduos cuja estrutura era predominantemente cilíndrica de orientação vertical, houve uma maior interação com a polarização VV. Os resultados indicaram também que a resposta radiométrica na banda P, de maior comprimento de onda, não foi tão eficaz quanto a interferometria (CohPvv e o LogHint) para estimativa dos parâmetros dendométricos estudados, obtendo índices de determinação de 84 a 88% em relação ao inventário florestal das áreas.Abstract The main goal of this paper was to establish the relationship between the forest dendrometric parameters and the interferometric and radiometric image response, obtained from a SAR sensor (Synthetic Aperture Radar), using multivariable regression techniques. A 6.1-year-old Eucalyptus grandis stand area was selected for this study. The results pointed out that the stand volume was highly correlated with the interferometric height logarithm (LogHint), obtained by the difference between interferometric models in X and P bands, whereas the DBH presented better relationship with the combination of VV coherence (CohPvv) and the LogHint. The commercial vegetation height, similar to the DBH, was better explained by the combination of CohPvv and LogHint. The results showed that due to the fact that the population of individuals whose structure was predominantly cylindrical and vertically oriented, caused a higher interaction with the vertical polarization. The higher wavelength P band radiometry efficacy wasn’t as good as the interferometry (CohPvv and LogHint) to estimate the dendometric parameters studied, which obtained 84 to 88% of determination coefficient in relation to the area forest inventory.

Aplicació de diverses tècniques de detecció i localització per detectar moviments amb un radar C2-FM que opera en banda W. [ANGLÈS] Integration of a SAR adquisition system using a FM-CW 94 GHz radar and test the system by different measurement campaigns with the aim of detecting micrometic displacements using a phase analysis of the recived signal [CASTELLÀ[ Integración de un sistema de adquisición SAR mediante el uso de un radar FM-CW a 94 GHz y probar la validez del mencionado sistema a partir de diferentes campañas de medidas con el objetivo de detectar desplazamientos de carácter micrométrico a partir de un análisis de la fase de la señal recibida. [CATALÀ] Integració d' un sistema d' adquisició SAR mitjançant un radar FM-CW a 94 GHz y provar la validesa del sistema a partir de diferents campanyes de mesures amb l'objetiu de detectar desplaçaments de caràcter micromètric a partir d' un anàlisi de la fase de la señal rebuda.

Orientador: Max Henrique Machado Costa Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação Resumo: Dois problemas importantes na interferometria SAR (Synthetic Aperture Radar) são a estimação da fase absoluta e das linhas de base. O conhecimento preciso da fase absoluta e das linhas de base são fundamentais para a geração de modelos digitais de superfície ou terreno com alta precisão planimétrica e altimétrica. A estimação de fase absoluta consiste de duas etapas. A primeira etapa efetua o desdobramento da fase, o qual recupera a fase absoluta com os correspondentes múltiplos de 2?. A segunda etapa consiste na estimação do deslocamento de fase, causada pela combinação de erros de sincronização no sistema de aquisição de dados com erros de processamento da Interferometria SAR (InSAR). A estimação de linha de base consiste na determinação da posição da antena escrava relativa à posição da antena mestre (ou antena de referência). As contribuições desta tese consistem na concepção e na implementação de três métodos que se valem de múltiplas antenas (múltiplos interferogramas) para resolver esses dois problemas, como se segue. O primeiro método efetua o método de desdobramento de fase pontual, através do desdobramento de fase iterativo dos interferogramas, seguido da fusão dos mesmos, usando máxima verossimilhança. O segundo método refina a estimação de fase absoluta através da estimação do deslocamento de fase usando múltiplas antenas não colineares. O método se baseia na minimização da distorção geométrica (ou erro relativo) induzida pelo processamento com a presença de deslocamentos de fase com valores diferentes do verdadeiro. Uma das vantagens do método é que ele dispensa a instalação de refletores de canto na região imageada. Por último, um algoritmo do tipo Monte Carlo foi desenvolvido para a determinação das posições relativas das antenas escravas em relação à antena mestre. O método utiliza refletores de canto, cujas posições em campo são conhecidas, para reduzir o erro quadrático médio Abstract: Two important issues in SAR interferometry (InSAR) are absolute phase and baseline estimation. The precise knowledge of these parameters is essential for the production of digital elevation models with high accuracy. The absolute phase estimation can be done in two steps. The first step performs the unwrapping of the phase, which retrieves the 2? multiples of the phase. The second step estimates the phase offset caused by a combination of errors in the acquisition system and in SAR interferometry (InSAR) processing. The baseline estimation determines the relative position of the slave antenna with respect to the master antenna (reference antenna). The contributions of this thesis consist in the design and implementation of three methods that use multiple antennas to address the above issues. The first method performs the unwrapping of the phase in a pixel based fashion, by iteratively unfolding the phase corresponding to each interferograma, followed by maximum likelihood fusion of the unwrapped phases. The second method refines the absolute phase estimation of the first step by incorporating a phase offset estimation based on multiple, noncollinear, antennas. This is achieved by minimizing the geometrical distortion (relative error) in the reconstructed digital elevation model induced by erroneous phase offsets in the interferograms. One advantage of this method is that it does not require the deployment of corner reflector in the area to be imaged. Lastly, the third method deals with baselines estimation. A baseline is determined by the relative positions of the slave and master antennas. The estimation is performed with a greedy stochastic algorithm of Monte Carlo type which uses corner reflectors with precisely known positions. A new position for the slave antenna is accepted when the mean square error of the corner reflector positions is reduced Doutorado Telecomunicações e Telemática Doutor em Engenharia Elétrica

Proyecto basado en la aplicación de diferentes estrategias de procesado mediante la técnica interferométrica. El objetivo es el de obtener una mayor cantidad de puntos de medida en zonas no urbanas donde la decorrelación temporal es muy alta. [ANGLÈS] Project based on the application of different processing strategies using the interferometric technique. The objective is to obtain a greater number of measuring points in non-urban areas where the temporal decorrelation is very high. [CASTELLÀ] Proyecto basado en la aplicación de diferentes estrategias de procesado mediante la técnica interferométrica. El objetivo es el de obtener una mayor cantidad de puntos de medida en zonas no urbanas donde la decorrelación temporal es muy alta. [CATALÀ] Projecte fonamentat en l'aplicació de diferents estratègies de processament mijançant la tècnica interferomètrica. L'objectiu és el d'obtenir una major quantitat de punts de mesura en zones on la decorrelació temporal és molt alta.

Se basa en el análisis de medidas procesadas de distintos datos de imágenes SAR de diferentes frecuencias. [ANGLÈS] In recent years many new developments have been made in the field of SAR image analysis. The diversity of available SAR imagery allows a wider range of applications to be covered in the domain of risk management and hazard mapping. The work proposed is based on the analysis of differences in ground deformation measurements extracted from the processing of data stacks acquired at different frequencies. The aim of the project is the definition of criteria that could assist in the selection of the most appropriate SAR mission according to the type of regions of interest. Key factors are geographic localization and land cover. In order to achieve the criteria definition, new methodologies had to be developed and included in the processing chain. [CASTELLÀ] En años recientes, se han hecho muchos avances en el campo de análisis de imágenes SAR. La diversidad de imágenes disponibles permite tener un amplio rango de aplicaciones a cubrir en el campo de gestión de riesgos y mapeo de zonas peligrosas. El trabajo propuesto está basado en el análisis de las diferencias de medidas de deformación del terreno a partir del procesado de imágenes adquiridas a diferentes frecuencias. El objetivo del proyecto es definir un criterio que ayude en la selección de la misión SAR más apropiada de acuerdo al tipo de región. Factores importantes son la localización geográfica y el tipo de cobertura de la superficie. Para poder lograr esto, nuevas metodologías tuvieron que ser desarrolladas e incluidas en la cadena de procesado. [CATALÀ] En anys recents, s'han fet molts avenços en el camp de l'anàlisi d'imatges SAR. La diversitat d'imatges disponibles permet tenir un ampli rang d'aplicacions a cobrir en el camp de la gestió de riscos i mapeig de zones perilloses. El treball proposat està basat en l'anàlisi de les diferències de mesures de deformació del terreny a partir del processat d'imatges adquirides a diferents freqüències. L'objectiu del projecte és definir un criteri que ajudi en la selecció de la missió SAR més apropiada d'acord al tipus de regió. Factors importants són la localització geogràfica i el tipus de cobertura de la superfície. Per poder aconseguir això, noves metodologies van haver de ser desenvolupades i incloses a la cadena de processament.

A topografia evidencia-se como um fator imprescindível no entendimento da dinâmica hidrológica e ambiental. Assim, torna-se fundamental a validação de dados altimétricos obtidos por sensoriamento remoto. Os dados SRTM de elevação são resultado de uma missão orbital por RADAR interferométrico que corresponde à topografia da superfície da Terra, considerando inclusive a influência da vegetação no retorno do sinal. O objetivo deste trabalho é validar os dados SRTM para as condições do semi-árido brasileiro. Para isto foram elaboradas comparações e análise estatística de dados obtidos no campo com GPS diferencial e outras bases de dados referenciais existentes, cartas planialtimétricas DSG/ SUDENE e dados de RN do IBGE em pontos localizados na bacia do rio Jaguaribe situada no semi-árido cearense. Os resultados apresentaram erro altimétrico de aproximadamente 7,0 m com relação aos RNs da bacia. Com uso do DGPS em um relevo plano com baixa declividade e com vegetação de porte baixo os resultados apontam um erro altimétrico de aproximadamente 1,7 m. Conclui-se que, apesar da influência da cobertura vegetal na variação altimétrica, os dados SRTM apresentam-se confiáveis para regiões com vegetação típica do semi-árido. Topography is a major factor for understanding hydrological and environmental dynamics. Therefore, validation of the altimetric data obtained by remote sensing is required. SRTM data are a result of an orbital mission by interferometer RADAR, corresponding to the Earth surface topography, also considering the influence of vegetation in the signal. The objective of this work is to validate SRTM data for the semi-arid conditions in Northeast Brazil. The methodology used consists in the comparison and statistical analysis of field data obtained with a differential GPS (DGPS) and other existing data bases such as the DSG/SUDENE topographic maps and level reference points from IBGE in the Jaguaribe basin, located in the semi-arid region of Ceará Federal State. Results present an elevation error of approximately 7 m in relation to the level reference points in the basin. The use of DGPS on a plan relief with very low slopes and vegetation with low height, resulted on an elevation error of approximately 1.7 m. It can be concluded that, despite the influence of the vegetation cover on the altimetric variation, SRTM data are reliable for regions with vegetation type typical of semi-arid regions.

Aquest projecte està emmarcat en el camp de la interferometria, una aplicació que permet tenir informació al llarg de l’eix d’observació d’una escena. La informació d’alçada s’extreu a partir del que s’anomena interferograma, que no és res més que una combinació de la informació d’una mateixa zona vista des de dos punts de vista diferents. De fet es pot anar més enllà, ja que el terreny no té perquè ser inamovible i pot deformar-se. Per tant es pot eliminar la component immòbil del terreny i restar només la informació de deformació. Així s’haurà creat l’anomenat interferograma diferencial.

A coherence optimization method, which makes use of polarimetry to enhance the quality of the interferograms, has been experimentally tested under laboratory conditions in an anechoic chamber. The experiments have proved the remarkable contribution that this technique offers in two important applications: the improvement of digital elevation maps (DEM) generation and the estimation of the height of vegetation targets

La interferometría con imágenes de radar de apertura sintética (SAR: Synthetic Aperture Radar) desde satélite es una técnica que permite obtener información altimétrica del relieve terrestre, siendo especialmente útil en áreas remotas. Este trabajo muestra una aplicación de esta técnica en las islas Shetland del Sur (Antártida). Para ello se han utilizado imágenes SAR obtenidas por los satélites ERS (European Remote Sensing) de la Agencia Espacial Europea (ESA: European Space Agency) y un proceso interferométrico desarrollado entre el Departament de Geodinàmica i Geofísica de la Universitat de Barcelona y el Institut Cartogràfic de Catalunya . En este documento se describen el proceso, los datos y la generación de un Modelo Numérico de Elevaciones (MNE) de la Isla Decepción., Satellite Synthetic Aperture Radar (SAR) interferometry is a technique that allows the generation of altimetric information. The technique is higly useful in remote areas and this paper shows an application of SAR interferometry in the South Shetland Islands (Antarctica). SAR images obtained by the ERS (European Remote Sensing) satellites of the European Space Agency (ESA) have been processed with an interferometric processor developed by the Departament de Geodinàmica i Geofísica of the Universitat de Barcelona in collaboration with the Institut Cartogràfic de Catalunya.

Ascending-descending orbit combination for DEM generation is very promising technique which can be used to fill in ome gaps in the DEMs caused by the geometric deformations or SAR images. The benefits from the combination over layover and foreshortening areas are evident thanks to the new data made available over these areas from the opposite pair. However, other areas in the image will also improve its quality because of the averaging between the ascending and the descending pass. This paper shows an ascending descending orbit combination using ERS data. Two ascending and descending DEMs have been calculated independently and a combined DEM has been obtained from them on a coherence basis. The obtained DEMs have been compared with a high accuracy DEM (2m height rms) available. Results show an error reduction in the combined DEM over the ascending and descending ones. Ascending-descending orbit combination SAR interferometry assessment (DEM).

SAR Interferometry allows the obtention of digital elevation models (DEM) by combination of two synthetic aperture radar images acquired from slightly different viewpoints. ERS-1 SAR interferometry has already been validated over small areas. When processing wider areas, new adaptative filtering algorithms such as the short time Fourier transform are required. However, phase unwrapping is still the critical step. LMS an weighted LMS are two phase unwrapping algorithms which overcome some disadvantages of traditional residue based methods. Some results are shown obtained from ERS-1 images from Tarragona.

In the past we proposed a multidimensional speckle noise model to which we now include systematic phase variation effects. This extension makes it possible to define what is believed to be a novel coherence model able to identify the different sources of bias when coherence is estimated on multidimensional synthetic radar aperture (SAR) data. On the one hand, low coherence biases are basically due to the complex additive speckle noise component of the Hermitian product of two SAR images. On the other hand, the availability of the coherence model permits us to quantify the bias due to topography when multilook filtering is considered, permitting us to establish the conditions upon which information may be estimated independently of topography. Based on the coherence model, two coherence estimation approaches, aiming to reduce the different biases, are proposed. Results with simulated and experimental polarimetric and interferometric SAR data illustrate and validate both, the coherence model and the coherence estimation algorithms.

Aquest treball consisteix en l'anàlisi i interpretació de mesures de deformació amb interferometria Radar (GBSAR) dutes a terme durant un assaig a llarg termini a escala real. L'element monitoritzat és una llosa experimental que s'està monitoritzant al llarg d'un any per veure la seva retracció amb el pas del temps i la seva dilatació per causes climàtiques (canvi de temperatura).

This paper is concerned with the radiometric sensitivity computation of an aperture synthesis interferometric radiometer devoted to Earth observation. The impact of system parameters and the use of simultaneous redundant measurements are analyzed. The interferometric radiometer uncertainty principle is presented; it quantifies the relationship between radiometric sensitivity and angular resolution.

Persistent Scatterers Interferometry (PSI) represents one of the most powerful techniques for Earth's surface deformation processes' monitoring, especially for long-term evolution phenomena. In this work, a dataset of 34 TerraSAR-X StripMap images (October 2013–October 2014) has been processed by two PSI techniques - Coherent Pixel Technique-Temporal Sublook Coherence (CPT-TSC) and Small Baseline Subset (SBAS) - in order to study the evolution of a slow-moving landslide which occurred on February 23, 2012 in the Papanice hamlet (Crotone municipality, southern Italy) and induced by a significant rainfall event (185 mm in three days). The mass movement caused structural damage (buildings' collapse), and destruction of utility lines (gas, water and electricity) and roads. The results showed analogous displacement rates (30–40 mm/yr along the Line of Sight – LOS-of the satellite) with respect to the pre-failure phase (2008–2010) analyzed in previous works. Both approaches allowed detect the landslide-affected area, however the higher density of targets identified by means of CPT-TSC enabled to analyze in detail the slope behavior in order to design possible mitigation interventions. For this aim, a slope stability analysis has been carried out, considering the comparison between groundwater oscillations and time-series of displacement. Hence, the crucial role of the interaction between rainfall and groundwater level has been inferred for the landslide triggering. In conclusion, we showed that the integration of geotechnical and remote sensing approaches can be seen as the best practice to support stakeholders to design remedial works.

The project is focused on the interferometric techniques applied to precise satellite positioning. These techniques are required in future Earth Observation radar satellites based on geostationary platforms. The industry of remote sensing has nowadays strongly developed systems, which are versatile and adaptable, however they are not optimal for certain applications. With more than enough reason from it, a new technology of remote sensing technique is being developed, specifically the technology of Synthetic Aperture Radars (SAR) mounted in Geostationary satellites. This paper does briefly explain the theory behind radars, and it does more specifically about SAR technology. It takes an informative view about their characteristics of the many different systems developed up to date and based on recently published analyses justifies the necessity of the GEOSAR, and attempts to validate and surmount the most important of its intrinsic flaws: the precise orbit determination. To fight these uncertainties, it studies the possibility to predict precisely its position with the help of an interferometer, an angle measurement system, which with correct configuration could reach the orbit precision required. The construction of this interferometer, is done through the profiting of a pre-existent Xband receiver, a commercial DVBSatellite television receiver, properly modified to fetch the signal in baseband and process the signal to acquire the phase from it. Although the system had not acquired the phase as it was expected due to several increasing complications within the system devices, this has has open a way for possible a future development of the research and with it achieve a low cost interferometer which could not only validate the GEOSAR orbit precision, but also can improve existing satellite tracking systems. La industria de la teledetección tiene a día de hoy sistemas fuertemente desarrollados, versátiles y adaptables, sin embargo, no son óptimos para ciertas aplicaciones A partir de ello, una nueva tecnología de teledetección está siendo desarrollada, específicamente la tecnología de radares de apertura sintética (SAR) en satélites geoestacionarios. Este trabajo explica brevemente la teoría de los radares, i lo hace más específicamente sobre los de tecnología SAR. El trabajo toma una posición informativa sobre sus características de los diferentes sistemas desarrollados a día de hoy i basado en estudios recientes justifica la necesidad del GEOSAR, además de intentar validar y superar el más importante de sus retos : poder determinar la posición orbital. Para luchar contra estas incertezas, estudia la posibilidad de predecir con precisión su posición con la ayuda de un interferómetro, un sistema medidor de ángulos, el cual con la configuración correcta puede lograr la precisión requerida. La construcción de este interferómetro, se hace a través del aprovechamiento de un receptor ya existente de banda X, un receptor de televisión satelital comercial apropiadamente modificado para obtener la diferencia de fases. Aunque el sistema no ha podido obtener la fase como era esperado debido a crecientes complicaciones con los dispositivos, ha abierto una nueva vía de desarrollo para los SAR y conseguir a través de un sistema interferométrico sencillo no solamente predecir orbitas precisas para satélites GEOSAR, sino para todos los sistemas de seguimiento satelital L'industria de la teledetecció té a dia d'avui sistemes fortament desenvolupats, versàtils i adaptables, malgrat això no són òptims per certes aplicacions. A partir d'això, una nova tecnologia de teledetecció està sent desenvolupada, específicament la tecnologia de radars d'apertura sintètica (SAR) en satèl·lits geoestacionaris. Aquest treball explica breument la teoria dels radars, i ho fa més específicament de la tecnologia SAR. El treball toma una posició informativa sobre les seves característiques dels diferents sistemes desenvolupades a dia d'avui i basat en estudis recents justifica la necessitat del GEOSAR, a més d'intentar validar i superar la més important dels seus reptes: poder determinar la posició orbital. Per lluitar contra aquestes incerteses, estudia la possibilitat de predir amb cura la seva posició amb l'ajuda d'un interferòmetre, un sistema mesurador d'angles, el qual amb la configuració correcta pot assolir la precisió requerida. La construcció d'aquest interferòmetre, es fa a través de l'aprofitament d'un receptor ja existent de banda X, un receptor de televisió satel·lital comercial apropiadament modificat per tal d'obtenir la fase. Malgrat que el sistema no ha pogut obtenir la fase com era esperat degut a creixents complicacions amb els dispositius, ha obert una nova via de desenvolupament dels SAR i aconseguir a través d'un sistema interferomètric senzill no solament per predir òrbites acurades per satèl·lits GEOSAR, sinó per tots els sistemes de seguiment satel·lital

This paper presents a flexible simulator for Ground Moving Target Indication (GMTI) in the frame of spaceborne Synthetic Aperture Radar (SAR) over maritime scenarios. The simulation tool provides GMTI performance metric in terms of probability of detection, extracted from an off-line database generated through intensive Monte Carlo (MC) simulations, overlaid on top of synthetic SAR-GMTI processed images. Different system configurations have been evaluated considering Along-Track Interferometry (ATI), Displaced Phase Center Antenna (DPCA) and Extended DPCA (EDPCA) GMTI techniques