REMOTE SENSING DATA ANALYSIS FOR ENVIRONMENTAL AND HUMANITARIAN PURPOSES. The automation of information extraction from free satellite data.

This work is aimed at investigating technical possibilities to provide information on environmental parameters that can be used for risk management. The World food Program (WFP) is the United Nations Agency which is involved in risk management for fighting hunger in least-developed and low-income countries, where victims of natural and manmade disasters, refugees, displaced people and the hungry poor suffer from severe food shortages. Risk management includes three different phases (pre-disaster, response and post disaster) to be managed through different activities and actions. Pre disaster activities are meant to develop and deliver risk assessment, establish prevention actions and prepare the operative structures for managing an eventual emergency or disaster. In response and post disaster phase actions planned in the pre-disaster phase are executed focusing on saving lives and secondly, on social economic recovery. In order to optimally manage its operations in the response and post disaster phases, WFP needs to know, in order to estimate the impact an event will have on future food security as soon as possible, the areas affected by the natural disaster, the number of affected people, and the effects that the event can cause to vegetation. For this, providing easy-to-consult thematic maps about the affected areas and population, with adequate spatial resolution, time frequency and regular updating can result determining. Satellite remote sensed data have increasingly been used in the last decades in order to provide updated information about land surface with an acceptable time frequency. Furthermore, satellite images can be managed by automatic procedures in order to extract synthetic information about the ground condition in a very short time and can be easily shared in the web. The work of thesis, focused on the analysis and processing of satellite data, was carried out in cooperation with the association ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action), a center of research which works in cooperation with the WFP in order to provide IT products and tools for the management of food emergencies caused by natural disasters. These products should be able to facilitate the forecasting of the effects of catastrophic events, the estimation of the extension and location of the areas hit by the event, of the affected population and thereby the planning of interventions on the area that could be affected by food insecurity. The requested features of the instruments are: • Regular updating • Spatial resolution suitable for a synoptic analysis • Low cost • Easy consultation Ithaca is developing different activities to provide georeferenced thematic data to WFP users, such a spatial data infrastructure for storing, querying and manipulating large amounts of global geographic information, and for sharing it between a large and differentiated community; a system of early warning for floods, a drought monitoring tool, procedures for rapid mapping in the response phase in a case of natural disaster, web GIS tools to distribute and share georeferenced information, that can be consulted only by means of a web browser. The work of thesis is aimed at providing applications for the automatic production of base georeferenced thematic data, by using free global satellite data, which have characteristics suitable for analysis at a regional scale. In particular the main themes of the applications are water bodies and vegetation phenology. The first application aims at providing procedures for the automatic extraction of water bodies and will lead to the creation and update of an historical archive, which can be analyzed in order to catch the seasonality of water bodies and delineate scenarios of historical flooded areas. The automatic extraction of phenological parameters from satellite data will allow to integrate the existing drought monitoring system with information on vegetation seasonality and to provide further information for the evaluation of food insecurity in the post disaster phase. In the thesis are described the activities carried on for the development of procedures for the automatic processing of free satellite data in order to produce customized layers according to the exigencies in format and distribution of the final users. The main activities, which focused on the development of an automated procedure for the extraction of flooded areas, include the research of an algorithm for the classification of water bodies from satellite data, an important theme in the field of management of the emergencies due to flood events. Two main technologies are generally used: active sensors (radar) and passive sensors (optical data). Advantages for active sensors include the ability to obtain measurements anytime, regardless of the time of day or season, while passive sensors can only be used in the daytime cloud free conditions. Even if with radar technologies is possible to get information on the ground in all weather conditions, it is not possible to use radar data to obtain a continuous archive of flooded areas, because of the lack of a predetermined frequency in the acquisition of the images. For this reason the choice of the dataset went in favor of MODIS (Moderate Resolution Imaging Spectroradiometer), optical data with a daily frequency, a spatial resolution of 250 meters and an historical archive of 10 years. The presence of cloud coverage prevents from the acquisition of the earth surface, and the shadows due to clouds can be wrongly classified as water bodies because of the spectral response very similar to the one of water. After an analysis of the state of the art of the algorithms of automated classification of water bodies in images derived from optical sensors, the author developed an algorithm that allows to classify the data of reflectivity and to temporally composite them in order to obtain flooded areas scenarios for each event. This procedure was tested in the Bangladesh areas, providing encouraging classification accuracies. For the vegetation theme, the main activities performed, here described, include the review of the existing methodologies for phenological studies and the automation of the data flow between inputs and outputs with the use of different global free satellite datasets. In literature, many studies demonstrated the utility of the NDVI (Normalized Difference Vegetation Index) indices for the monitoring of vegetation dynamics, in the study of cultivations, and for the survey of the vegetation water stress. The author developed a procedure for creating layers of phenological parameters which integrates the TIMESAT software, produced by Lars Eklundh and Per Jönsson, for processing NDVI indices derived from different satellite sensors: MODIS (Moderate Resolution Imaging Spectroradiometer), AVHRR (Advanced Very High Resolution Radiometer) AND SPOT (Système Pour l'Observation de la Terre) VEGETATION. The automated procedure starts from data downloading, calls in a batch mode the software and provides customized layers of phenological parameters such as the starting of the season or length of the season and many others

Development of automated tools for detailed monitoring of mussel and oyster beds using satellite data: spatial, temporal and vertical development

The main focus of this report is to develop the application of a novel technique in mapping of mussel and oyster beds using remote sensing, which can be combined with regular field monitoring to obtain an optimal monitoring strategy

Design of a generic end-to-end mission performance simulator and application to the performance analysis of the FLEX/Sentinel-3 mission

La Observación de la Tierra mediante técnicas de teledetección con instrumentos ópticos en satélite tiene como objetivo monitorizar los procesos bio-geofísicos en la superficie y atmósfera terrestre, adquiriendo datos a diferentes longitudes de onda del espectro electromagnético. Con el fin de asegurar el mantenimiento de las observaciones y las capacidades para entender el sistema Tierra, nuevas misiones satelitales están siendo desarrolladas por agencias espaciales nacionales e internacionales así como organizaciones de investigación. En este contexto, los simuladores de misiones espaciales (E2ES por sus siglas en inglés, End-to-End Mission Performance Simulator) ofrecen a los científicos e ingenieros un marco único para entender el impacto de la configuración del instrumento en los productos finales de la misión y, por tanto, acelerar el desarrollo de una misión desde la fase conceptual hasta el lanzamiento. Al mismo tiempo, estas herramientas permiten definir una metodología para la consolidación de los requisitos y la evaluación de la actuación de estas misiones satelitales, estableciendo criterios para la selección de una misión por las diferentes agencias espaciales. Mientras que el concepto de un E2ES es simple, el diseño de nuevos E2ES y la evolución de los ya existentes tienen una falta de guias y metodología estandarizadas, lo cual se traduce en un caro y complejo proceso de re-ingeniería. Esta tesis cubre dos objetivos principales. Por un lado, se pretende armonizar el trabajo hecho en el campo de los E2ES durante las últimas décadas y proponer una serie de guias y metodologías para desarrollas E2ES para misiones satelitales futuras con instrumentos ópticos pasivos. El primer objetivo es por tanto "Diseñar un simulador de misión genérico que pueda ser fácilmente adaptado para reproducir la mayoría de misiones satelitales, presentes y futuras, con sensores ópticos pasivos". Por otro lado, la misión FLEX/Sentinel-3 de la ESA se usa para validar, a través de la implementación de su propio E2ES, el diseño de la arquitectura genérica tratada en el punto anterior. De este modo, el E2ES para la misión FLEX permite evaluar la actuación de la misión para la obtención de la fluorescencia inducida por radiación solar emitida por la vegetación terrestre. La misión FLEX/Sentinel-3 es una candidata óptima para esta tarea de validación dada la complejidad de la misión (p.ej. vuelo en tandem, multi-plataforma/-instrumento, múltiples rangos y resoluciones espectrales, observaciones multi-angulares, sinergia de productos). El segundo objetivo de esta tesis es por tanto "Evaluar la misión FLEX para la la observación de la emisión de fluorescencia emitida por la vegetación usando un E2ES desarrollado de acuerdo con una arquitectura genérica". La razón fundamental tras esta Tesis es promocionar el uso de una arquitectura genérica común para los E2ES que permita comparar misiones satelitales en procesos de selección competitiva como los Earth Explorer de la ESA así como acelerar el análisis de los requisitos técnicos y el rendimiento de la misión a nivel científico. Particularmente, esto se muestra mediante la implementación de esta arquitectura genérica para el caso específico de la misión FLEX/Sentinel-3 demostrando que: (1) la misión es capaz de obtener con la precisión requerida la emisión de fluorescencia por la vegetación ; y (2) el concepto de esta arquitectura genérica es apto para reproducir la complejidad de la misión FLEX/Sentinel-3 y por tanto se espera que esta metodología pueda ser también aplicable para un gran abanico de misiones ópticas pasivas. Esta base lógica se consigue a partir de una categorización de varias misiones satelitales y la identificación y análisis de los elementos principales que afectan en el rendimiento de la misión e impactan en la arquitectura de un simulador de misión. La arquitectura genérica para E2ES propuesta se valida mediante la implementación del E2ES de la misión FLEX/Sentinel-3 de la ESA teniendo en cuenta ambos satélites, sus instrumentos, y evaluando con este E2ES el rendimiento de la misión FLEX. En esta Tesis, los capítulos 1 y 2 introducen los principales temas de esta Tesis y definen los conceptos básicos. Los capítulos 3 al 5 describe el diseño de la arquitectura genérica para los E2ES en misiones ópticas pasivas. Finalmente, el capítulo 6 resume los principales resultados y las conclusiones derivadas de esta Tesis.Earth observation by satellite optical remote sensing aims to monitor bio-geophysical processes happening in the Earth surface and the atmosphere by acquiring data at different wavelengths of the electromagnetic spectrum. In order to ensure sustained observations and capabilities to fill scientific gaps in our current understanding of the Earth system, new satellite missions are being developed by national and international space agencies and research organisations. In this context, End-to-End Mission Performance Simulator (E2ES) tools offer scientists and engineers a unique framework to understand the impact of instrument configuration in the final mission products and to accelerate the mission development from concept to deployment. At the same time, these cost-effective and flexible tools are capable of defining a methodology for the consolidation of requirements and performance assessment of these new satellite missions, setting the criteria for mission selection by the various space agencies’ programme boards. While the concept of an E2ES is simple, the design of new E2ES and the evolution of existing ones lack from a standard methodology and guidelines, which translates into a complex and costly re-engineering process. This Thesis covers two main objectives. On the one hand, it aims to harmonize the work done in the field of E2ES during the last decades and to propose a set of guidelines or methodology to develop E2ES for future remote sensing satellite passive optical missions. The first main objective, therefore, is: ’To design a generic end-to-end mission performance simulator that can be easily adapted to reproduce most present or future passive optical spaceborne instruments’. On the other hand, the ESA’s FLEX/Sentinel-3 tandem mission is used to validate, through the implementation of its E2ES, the designed generic E2ES architecture and to evaluate the performance of the FLEX mission for the retrieval of Sun-induced fluorescence. The FLEX/Sentinel- 3 mission is optimally suitable for this validation task due to the complexity of the mission (e.g. tandem flight, multi-platform/-instrument mission, multiple spectral ranges and resolutions, multi-angular observations, synergy of products). The second main objective, therefore, is: ’To evaluate the FLEX mission for Sun-induced fluorescence retrievals using a newly developed E2ES in agreement with the designed generic E2ES architecture.’. The rationale behind this Thesis is promoting the use of a common generic E2ES architecture that allows comparing missions in competitive selection process (e.g., ESA’s Earth Explorers) and speeding-up the analysis of the mission technical requirements and scientific performances. Particularly, this is shown by implementing this generic E2ES architecture for the specific case of FLEX/Sentinel-3 mission demonstrating that: (1) the mission is capable of retrieving Sun-induced fluorescence within the required accuracy; and (2) the conceptual generic E2ES architecture is suitable toreproduce the complexity of the FLEX/Sentinel-3 tandem mission and thus it is expected to be also applicable for a wide range of passive optical missions. This rationale is achieved by categorising several satellite missions to identify and analyse the main elements that affect the mission performance and impact the simulator architecture. The proposed generic E2ES architecture is validated by implementing the ESA’s FLEX/Sentinel-3 E2ES, both satellites and their instruments, and testing it through the performance assessment of the FLEX mission products. In this Thesis, Chapters 1 and 2 introduce the main research questions and sets the background concepts. Then Chapters 3–5 describe the design of a generic E2ES architecture for passive optical missions. Finally, Chapter 6 summarizes the main results and conclusions derived in this Thesis

Remote Sensing

This dual conception of remote sensing brought us to the idea of preparing two different books; in addition to the first book which displays recent advances in remote sensing applications, this book is devoted to new techniques for data processing, sensors and platforms. We do not intend this book to cover all aspects of remote sensing techniques and platforms, since it would be an impossible task for a single volume. Instead, we have collected a number of high-quality, original and representative contributions in those areas

REMOTE SENSING DATA ANALYSIS FOR ENVIRONMENTAL AND HUMANITARIAN PURPOSES. The automation of information extraction from free satellite data

This work is aimed at investigating technical possibilities to provide information on environmental parameters that can be used for risk management. The World food Program (WFP) is the United Nations Agency which is involved in risk management for fighting hunger in least-developed and low-income countries, where victims of natural and manmade disasters, refugees, displaced people and the hungry poor suffer from severe food shortages. Risk management includes three different phases (pre-disaster, response and post disaster) to be managed through different activities and actions. Pre disaster activities are meant to develop and deliver risk assessment, establish prevention actions and prepare the operative structures for managing an eventual emergency or disaster. In response and post disaster phase actions planned in the pre-disaster phase are executed focusing on saving lives and secondly, on social economic recovery. In order to optimally manage its operations in the response and post disaster phases, WFP needs to know, in order to estimate the impact an event will have on future food security as soon as possible, the areas affected by the natural disaster, the number of affected people, and the effects that the event can cause to vegetation. For this, providing easy-to-consult thematic maps about the affected areas and population, with adequate spatial resolution, time frequency and regular updating can result determining. Satellite remote sensed data have increasingly been used in the last decades in order to provide updated information about land surface with an acceptable time frequency. Furthermore, satellite images can be managed by automatic procedures in order to extract synthetic information about the ground condition in a very short time and can be easily shared in the web. The work of thesis, focused on the analysis and processing of satellite data, was carried out in cooperation with the association ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action), a center of research which works in cooperation with the WFP in order to provide IT products and tools for the management of food emergencies caused by natural disasters. These products should be able to facilitate the forecasting of the effects of catastrophic events, the estimation of the extension and location of the areas hit by the event, of the affected population and thereby the planning of interventions on the area that could be affected by food insecurity. The requested features of the instruments are: • Regular updating • Spatial resolution suitable for a synoptic analysis • Low cost • Easy consultation Ithaca is developing different activities to provide georeferenced thematic data to WFP users, such a spatial data infrastructure for storing, querying and manipulating large amounts of global geographic information, and for sharing it between a large and differentiated community; a system of early warning for floods, a drought monitoring tool, procedures for rapid mapping in the response phase in a case of natural disaster, web GIS tools to distribute and share georeferenced information, that can be consulted only by means of a web browser. The work of thesis is aimed at providing applications for the automatic production of base georeferenced thematic data, by using free global satellite data, which have characteristics suitable for analysis at a regional scale. In particular the main themes of the applications are water bodies and vegetation phenology. The first application aims at providing procedures for the automatic extraction of water bodies and will lead to the creation and update of an historical archive, which can be analyzed in order to catch the seasonality of water bodies and delineate scenarios of historical flooded areas. The automatic extraction of phenological parameters from satellite data will allow to integrate the existing drought monitoring system with information on vegetation seasonality and to provide further information for the evaluation of food insecurity in the post disaster phase. In the thesis are described the activities carried on for the development of procedures for the automatic processing of free satellite data in order to produce customized layers according to the exigencies in format and distribution of the final users. The main activities, which focused on the development of an automated procedure for the extraction of flooded areas, include the research of an algorithm for the classification of water bodies from satellite data, an important theme in the field of management of the emergencies due to flood events. Two main technologies are generally used: active sensors (radar) and passive sensors (optical data). Advantages for active sensors include the ability to obtain measurements anytime, regardless of the time of day or season, while passive sensors can only be used in the daytime cloud free conditions. Even if with radar technologies is possible to get information on the ground in all weather conditions, it is not possible to use radar data to obtain a continuous archive of flooded areas, because of the lack of a predetermined frequency in the acquisition of the images. For this reason the choice of the dataset went in favor of MODIS (Moderate Resolution Imaging Spectroradiometer), optical data with a daily frequency, a spatial resolution of 250 meters and an historical archive of 10 years. The presence of cloud coverage prevents from the acquisition of the earth surface, and the shadows due to clouds can be wrongly classified as water bodies because of the spectral response very similar to the one of water. After an analysis of the state of the art of the algorithms of automated classification of water bodies in images derived from optical sensors, the author developed an algorithm that allows to classify the data of reflectivity and to temporally composite them in order to obtain flooded areas scenarios for each event. This procedure was tested in the Bangladesh areas, providing encouraging classification accuracies. For the vegetation theme, the main activities performed, here described, include the review of the existing methodologies for phenological studies and the automation of the data flow between inputs and outputs with the use of different global free satellite datasets. In literature, many studies demonstrated the utility of the NDVI (Normalized Difference Vegetation Index) indices for the monitoring of vegetation dynamics, in the study of cultivations, and for the survey of the vegetation water stress. The author developed a procedure for creating layers of phenological parameters which integrates the TIMESAT software, produced by Lars Eklundh and Per Jönsson, for processing NDVI indices derived from different satellite sensors: MODIS (Moderate Resolution Imaging Spectroradiometer), AVHRR (Advanced Very High Resolution Radiometer) AND SPOT (Système Pour l'Observation de la Terre) VEGETATION. The automated procedure starts from data downloading, calls in a batch mode the software and provides customized layers of phenological parameters such as the starting of the season or length of the season and many other