[pt] Objetivo. Fornecer confiabilidade às medições do LIDAR a partir: (i) do estabelecimento de padrões de configuração dos parâmetros do equipamento, na obtenção de sinais de fluorescência para medições de pigmentos em água; (ii) da avaliação de diferentes procedimentos para melhorar a relação sinal-ruído, preservando a integridade das bandas de interesse contidas no espectro de fluorescência; (iii) da verificação da repetitividade do equipamento para medições de comprimentos de onda associados aos máximos do espalhamento Raman da água, da banda de clorofila a, assim como, da banda de matéria orgânica dissolvida (MOD); (iv) e da avaliação da eficiência do processamento desenvolvido para obtenção de concentrações relativas da clorofila a quando comparadas aos resultados correlacionados à concentrações absolutas desse tipo de pigmento. Motivação. Contribuir para o desenvolvimento do monitoramento remoto utilizando um sistema LIDAR, fornecendo parâmetros que possibilitem maior confiabilidade às informações adquiridas pelo sistema. Contextualização. O monitoramento ambiental é uma prática adotada com maior freqüência por inúmeras empresas e instituições com o objetivo de minimizar impactos nocivos ao meio ambiente. O monitoramento remoto é uma ótima alternativa, pois, possibilita um levantamento prévio de possíveis vazamentos de diferentes tipos de poluição, sendo sensível à avaliação de sutis alterações no meio, possibilitando a identificação desses problemas antes mesmo de se tornarem aparentes. Metodologia. A prática adotada na obtenção de êxito dos objetivos apontados baseou-se: (i) na coleta de informação de diferentes modelos de monitoramento remoto, principalmente, utilizando um sistema LIDAR; (ii) na coleta de dados através da experimentação em laboratório e em campo e (iii) no desenvolvimento de processos que possibilitaram a análise das informações contidas nos sinais obtidos. Resultados. Na busca de um sinal-padrão de resposta do equipamento, o trabalho consiste em análises experimentais e no desenvolvimento de processos que auxiliem na análise das informações contidas nos sinais. Dentre os experimentos pode-se destacar duas abordagens: (i) a primeira, no laboratório, a partir de análise de amostras de água pura, que avalia as flutuações do sinal de fluorescência do espalhamento Raman da água para diferentes parâmetros do equipamento; (ii) e uma segunda análise, com dados in vivo, que avalia a concentração relativa de clorofila a para diferentes processos a fim de obter um processo padrão que diminui a sua incerteza na determinação desse quantitativo. Conclusões. O sensoriamento retomo é uma técnica útil para a investigação ambiental, porém, a implantação de práticas que contribuem para o aumento da confiabilidade dos dados fornecidos pelo sistema são igualmente indispensáveis. / [en] Aim. Providing reliability of LIDAR readings of fluorescence signals for measurements of pigments in ocean water by: (i) establishing configuration standards for equipment parameters. (ii) assessing different procedures to improve the signal-tonoise relationship. (iii) preserving the integrity of the wavelength bandwidth of the fluorescence spectrum. (iv) verifying the repeatability of wavelength measurements associated with local maxima of the Raman scattering curve of ocean water and chlorophyll a, as well as organic materials (dissolved in water) bandwidths. (v) and assessing the efficiency of the methodology developed for obtaining relative concentrations of chlorophyll a. Motivation. Contributing to the development of remote monitoring when using the LIDAR technique. This would bring about greater reliability. Context. Over the years environmental surveillance has been adopted by many companies and institutions as an effective practice to minimize harmful impacts on the environment. The remote monitoring is unquestionably a versatile alternative for detecting possible leaking of noxious substances before they become apparent. Methodology. The procedures included: (i) collecting information of different physical models of remote monitoring. (ii) collecting data from experiments carried out in the laboratory and in situ. (iii) and developing a procedure to analyze signal information. Results. Two approaches were adopted when carrying out the experiments: (i) in the laboratory, by evaluating fluorescence signal fluctuations of the Raman scattering in ocean water for different equipment parameters. (ii) and in situ, by measuring the relative concentration of chlorophyll a in ocean water for different schemes in order to choose the standard one. Conclusions. The remote monitoring is a useful tool to carry out environmental surveillance. But to increase the reliability of data collected by the optical-laser system apparatus the introduction of metrological assessment procedures is mandatory.

There is a range of detailed research on edge effects using field data at local scales. However, the scientific literature lacks studies that aim to understand its characteristics in forest fragments using larger scales. Also, few works have considered the influences that each fragment of the landscape imposes on its neighbour. Since biological processes linked to fragmentation and degradation commonly start at edges and influence the dynamics of forest communities, studies on edge effects are crucial for the development of management and conservation plans. Lidar technologies have been used in several studies on forest structure, but few have investigated edge effects. This dissertation presents two distinct applications of lidar for studying anthropogenic-caused edges in different scenarios and ecosystems. In the first study, edge effects in commercial Eucalyptus plantations and fragments of the Atlantic Forest, located in the State of São Paulo, were evaluated by quantifying the differences in height and understory density in the edge vegetation vs core. We also sought to understand the influences that each type of adjacent fragment (Eucalyptus, native forest or pasture) imposes on the neighbouring vegetation. Edge effects, regarding height and understory density, on fragments of native vegetation adjacent to Eucalyptus plantations and vice-versa were more attenuated than nearby pastures. The results indicated that the protection of native forests in silviculture areas besides favouring the maintenance of local ecosystem services (provision and maintenance of water flow, diversity of flora and fauna species, natural pest control, etc.) could help maintain the homogeneity of the stands due to their ability to minimise edge effects. This protection could favour the occurrence of border Eucalyptus more similar to the ones in the core. In the second study, edge effects caused by seismic lines, i.e. corridors cut through the forest during the process of exploration of gas and oil, in areas of Boreal Forest in the central region of Alberta is addressed. Besides quantifying the effects of distance from seismic lines over height and fractional cover on the neighbouring vegetation, the interactions between these variables and primary vegetation growth factors related to the topographic position, incident radiation and surface geology were evaluated. The results showed that significant changes in vegetation structure adjacent to forest edge occur close to seismic lines, including reduced tree height and cover. Random Forest analyses revealed that the distance from the seismic line, incident radiation and surface water accumulation potential (inferred from the topographic position index) are the most critical variables for height and fractional cover prediction. Overall, lidar proved to be a robust tool for assessing the spatial and ecological dimensions of edge effects in different scenarios. With this in mind, management and conservation strategies for fragmented areas could benefit from this technology to reduce the impact from edge effects on ecosystems. / Há uma gama de pesquisas detalhadas sobre efeitos de borda usando dados de campo em escalas locais. No entanto, a literatura científica carece de trabalhos que visem compreender suas características em fragmentos florestais utilizando escalas maiores. Além disso, poucos estudos levaram em conta as influências que cada fragmento da paisagem impõe sobre seu vizinho. Uma vez que processos biológicos ligados à fragmentação e degradação geralmente se iniciam pelas bordas e influenciam a dinâmica das comunidades florestais, estudos sobre efeitos de borda são cruciais para o desenvolvimento de planos de manejo e conservação. Tecnologias lidar têm sido usadas em diversos estudos sobre a estrutura de florestas, mas poucos trabalhos investigaram efeitos de borda. Esta dissertação apresenta duas aplicações distintas do lidar para o estudo de bordas criadas pelo homem em diferentes cenários e ecossistemas. No primeiro estudo, efeitos de borda em plantios comerciais de eucalipto e fragmentos de Mata Atlântica, no Estado de São Paulo, foram avaliados por meio da quantificação das diferenças na altura e densidade do sub-bosque na vegetação da borda vs. interior. Buscou-se também compreender as influências que cada tipo de fragmento adjacente (eucalipto, floresta nativa ou pasto) impõe sobre a vegetação vizinha. Os efeitos de borda, em termos de altura e densidade do sub-bosque, em fragmentos de vegetação nativa adjacentes aos plantios de eucalipto e vice-versa foram mais atenuados do que próximo às pastagens. Os resultados indicaram que a proteção de florestas nativas em áreas de silvicultura além de favorecer a manutenção de serviços ecossistêmicos locais (provisão e manutenção do fluxo de água, diversidade de espécies da flora e fauna, controle natural de pragas etc.) poderia ajudar a manter a homogeneidade dos talhões devido à sua capacidade de minimizar os efeitos de borda. Esta proteção poderia favorecer a ocorrência de eucaliptos de borda mais semelhantes aos de interior. No segundo estudo, foram abordados efeitos de borda causados pela abertura de linhas sísmicas durante o processo de exploração de gás e petróleo em áreas de Floresta Boreal, na região central de Alberta. Além da quantificação dos efeitos da distância das linhas sísmicas na altura e cobertura arbórea da vegetação vizinha, foram avaliadas as interações entre tais variáveis e fatores de crescimento primário da vegetação relacionados a posição topográfica, radiação e superfície geológica. Os resultados mostraram que variações significativas na estrutura da vegetação adjacente à borda da floresta ocorrem próximas às linhas sísmicas, incluindo altura e cobertura arbórea reduzidas. Análises por meio de florestas aleatórias (random forest) revelaram que a distância da linha sísmica, a radiação incidente e o potencial de acumulação de água superficial (inferida a partir do índice de posição topográfica) são as variáveis mais importantes para predição de altura e cobertura arbórea. No geral, o lidar se mostrou uma ferramenta robusta para avaliar as dimensões espaciais e ecológicas dos efeitos de borda em diferentes cenários. Com isso em mente, estratégias de manejo e conservação para áreas fragmentadas poderiam se beneficiar desta tecnologia para redução do impacto de efeitos de borda nos ecossistemas.

Sensors based on LiDAR (Light Detection and Ranging) technology have the potential to provide accurate 3D models of the trees retrieving information such as canopy volume and height. This information can be used for diagnostics and prescriptions of fertilizers and plant protection products on a site-specific basis. This research aimed to investigate the use of LiDAR sensors in orange crops. Orange is one of the most important tree crop in Brazil. So far, research have developed and tested LiDAR based systems for several tree crops. However, usually individual trees or small field plots have been used. Therefore, several aspects related to data acquisition and processing must still be developed for large-scale application. The first study reported in this document (Chapter 3) aimed to develop and test a mobile terrestrial laser scanner (MTLS) and new data processing methods in order to obtain 3D models of large commercial orange groves and spatial information about canopy geometry. A 2D laser sensor and a RTK-GNSS receiver (Real Time Kinematics - Global Navigation Satellite System) were mounted on a vehicle. The data processing was based on generating a georeferenced point cloud, followed by the filtering, classification and surface reconstruction steps. A 25 ha commercial orange grove was used for field validation. The developed data acquisition and processing system was able to produce a reliable point cloud of the grove, providing high resolution canopy volume and height information. The choice of the type of point cloud classification (by individual trees or by transversal sections of the row) and the surface reconstruction algorithm is discussed in this study. The second study (Chapter 4) aimed to characterize the spatial variability of canopy geometry in commercial orange groves. Understanding such variability allows sensor-based variable rate application of inputs (i.e, applying proportional rates of inputs based on the variability of canopy size) to be considered as a suitable strategy to optimize the use of fertilizers and plant protection products. Five commercial orange groves were scanned with the developed MTLS system. According to the variability of canopy volume found in those groves, the input savings as a result of implementing sensor-based variable rate technologies were estimated in about 40%. The second goal of this study was to understand the relationship between canopy geometry and several other relevant attributes of the groves. The canopy volume and height maps of three groves were analyzed against historical yield maps, elevation, soil electrical conductivity, organic matter and clay content maps. The correlations found between canopy geometry and yield or soil maps varied from poor to strong correlations, depending on the grove. When classifying the groves into three classes according to canopy size, the yield performance and soil features inside each class was found to be significantly different, indicating that canopy geometry is a suitable variable to guide management zones delineation in one grove. Overall results from this research show the potential of MTLS systems and subsequent data analysis in orange crops indicating how canopy geometry information can be used in site-specific management practices. / Sensores baseados em tecnologia LiDAR (Light Detection and Ranging) têm o potencial de fornecer modelos tridimensionais de árvores, provendo informações como o volume e altura de copa. Essas informações podem ser utilizadas em diagnósticos e recomendações localizadas de fertilizantes e defensivos agrícolas. Este estudo teve como objetivo investigar o uso de sensores LiDAR na cultura da laranja, uma das principais culturas de porte arbóreo no Brasil. Diversas pesquisas têm desenvolvido sistemas LiDAR para culturas arbóreas. Porém, normalmente tais sistemas são empregados em plantas individuais ou em pequenas áreas. Dessa forma, diversos aspectos da aquisição e processamento de dados ainda devem ser desenvolvidos para viabilizar a aplicação em larga escala. O primeiro estudo deste documento (Capítulo 3) focou no desenvolvimento de um sistema LiDAR (Mobile Terrestrial Laser Scanner - MTLS) e nova metodologia de processamento de dados para obtenção de informações acerca da geometria das copas em pomares comerciais de laranja. Um sensor a laser e um receptor RTK-GNSS (Real Time Kinematics - Global Navigation Satellite System) foram instalados em um veículo para leituras em campo. O processamento de dados foi baseado na geração de uma nuvem de pontos, seguida dos passos de filtragem, classificação e reconstrução da superfície das copas. Um pomar comercial de laranja de 25 ha foi utilizado para a validação. O sistema de aquisição e processamento de dados foi capaz de produzir uma nuvem de pontos representativa do pomar, fornecendo informação sobre geometria das plantas em alta resolução. A escolha sobre o tipo de classificação da nuvem de pontos (em plantas individuais ou em seções transversais das fileiras) e sobre o algoritmo de reconstrução de superfície, foi discutida nesse estudo. O segundo estudo (Capítulo 4) buscou caracterizar a variabilidade espacial da geometria de copa em pomares comerciais. Entender tal variabilidade permite avaliar se a aplicação em taxas variáveis de insumos baseada em sensores LiDAR (aplicar quantias de insumos proporcionais ao tamanho das copas) é uma estratégia adequada para otimizar o uso de insumos. Cinco pomares comerciais foram avaliados com o sistema MTLS. De acordo com a variabilidade encontrada, a economia de insumos pelo uso da taxa variável foi estimada em aproximadamente 40%. O segundo objetivo desse estudo foi avaliar a relação entre a geometria de copa e diversos outros parâmetros dos pomares. Os mapas de volume e altura de copa foram comparados aos mapas de produtividade, elevação, condutividade elétrica do solo, matéria orgânica e textura do solo. As correlações entre geometria de copa e produtividade ou fatores de solo variaram de fraca até forte, dependendo do pomar. Quando os pomares foram divididos entre três classes com diferentes tamanhos de copas, o desempenho em produtividade e as características do solo foram distintas entre as três zonas, indicando que parâmetros de geometria de copa são variáveis úteis para a delimitação de unidades de gestão diferenciada em um pomar. Os resultados gerais desta pesquisa mostraram o potencial de sistemas MTLS para pomares de laranja, indicando como a geometria de copa pode ser utilizada na gestão localizada de pomares de laranja.

No âmbito das mudanças climáticas globais, a quantificação do estoque de carbono em povoamentos florestais tem recebido mais atenção, principalmente pelo fato das florestas exercerem um papel fundamental no equilíbrio do estoque de carbono global. Com o objetivo de contribuir para esse processo, a parte investigativa deste trabalho foi desenvolvida em duas etapas. A primeira etapa objetivou o ajuste de modelos alométricos para a estimativa do estoque de carbono presente na biomassa total (Ctotal), no lenho comercial (Cleco) e parte residual (Crds) (casca, folhas e galhos) em plantações de Eucalyptus spp. em nível de árvores, através de uma amostragem destrutivas de árvores, análise elementar do carbono em laboratório e medidas convencionais de inventário. A medição do diâmetro à altura do peito (DAP) e altura total das árvores em parcelas amostradas instaladas nos talhões onde as árvores foram coletadas para determinação direta de carbono também foi realizada. A segunda parte, consistiu na avaliação do uso da tecnologia LiDAR (Light Detection and Ranging) aerotransportada (Airborne LASER scanning) como uma alternativa eficiente e versátil para a estimativa do estoque de carbono total (Ctotal), no lenho comercial de toras (Cleco) e no resíduo da árvore (Crds) em nível de parcelas em plantações de Eucalyptus spp usando como base o estoque de carbono estimado na primeira fase. Os resultados obtidos encontram-se resumidos em dois artigos científicos. O primeiro artigo mostra que os modelos baseados no logaritmo do diâmetro à altura do peito (DAP) e da altura total da árvore (Ht) oferecem boas precisão e exatidão para estimar o estoque de carbono em nível de árvore. O segundo artigo, permitiu a determinação das melhores métricas LiDAR para o cálculo do teor total de carbono, tanto no carbono total, lenho comercial e nas partes residuais da árvore em nível de plantação. Esses resultados, bem como os indicadores estatísticos utilizados para avaliar a qualidade dos ajustes, são o cerne desta dissertação. / In the context of global climate change, the quantification of the carbon content in forest plantations have received great attention. This is because vegetation play an important role in the global carbon budget. This master thesis was developed in two main parts. The first part was to adjust allometric equations for the estimation of the carbon content at a tree level. This was performed for the above ground section (Ctotal), in commercial logs (Cleco) and residuals ( Crds) (e.g. bark, leaves and branches/twigs). The experiment was based on the destructive model of individual trees harvested in commercial plantations of Eucaliptus spp. The experiment encompasses both forest inventory and laboratory analyses procedures. Additionally, in-situ measurements such as the diameter at the breast height (DBH) and the total tree height were also performed. These sample plots were located in homogeneous forest units and close to the areas were the trees have been harvested. The second part of this master thesis was the evaluation of the airborne LiDAR technology as a tool for the retrieval of the above ground biomass (Ctotal), the carbon present in the commercial logs (Cleco) and residuals. This procedure was performed at the sample plots level. This procedure was based on the information provided in the first part. The results are presented as two scientific manuscripts. The first manuscript shows that allometric equations based on the log of the variables diameter at the breast height (DBH) and total tree height (Ht) were good predictors for the retrieval of the total carbon content at a tree level. The second manuscript allow the selection of the best LiDAR derived metrics for the retrieval of the total carbon content, either at above ground level, commercial logs and residual parts of the tree at a sample plots level. These results, as well as the statistical indicators for the adjustment of several statistical models is the core of this master thesis.

Parce que les processus nuageux sont des processus complexes qui opèrent à des échelles spatiales très différentes, l'évolution de l'effet radiatif des nuages (CRE) dans un climat qui se réchauffe est incertaine. Afin de mieux comprendre l'évolution du CRE, il est utile de l'exprimer en fonction de propriétés nuageuses fondamentales et observables. Dans l'infrarouge (LW), l'altitude des nuages est une des propriétés fondamentales, ainsi que leur couverture et leur opacité. Les observations collectées par le lidar spatial CALIOP durant la dernière décennie nous ont permis d'exprimer le CRE LW en fonction de cinq propriétés nuageuses. Nous montrons que le CRE LW dépend linéairement de l'altitude des nuages. Cette linéarité permet de décomposer les variations du CRE LW en contributions dues aux cinq propriétés nuageuses. On observe ainsi que la couverture des nuages opaques a piloté les variations du CRE LW durant la dernière décennie. L'analyse de simulations climatiques suivant la même approche à l'aide d'un simulateur lidar montre que les variations du CRE LW dans le climat actuel sont pilotées par l'altitude des nuages opaques, en désaccord avec les observations. Lorsqu'on étend cette analyse aux rétroactions nuageuses LW simulées dans un climat futur, on remarque que celles-ci sont également pilotées par l'altitude des nuages opaques. Ces résultats suggèrent que les observations par lidar spatial apportent une forte contrainte observationnelle sur les rétroactions nuageuses LW, qui sont l'une des principales sources d'incertitude dans les prévisions d'évolution de la température moyenne globale dues aux activités humaines. / Because cloud processes are complex processes which operate at very different spatial scales, the evolution of the cloud radiative effect (CRE) in a warming climate is uncertain. To improve our understanding of the evolution of the CRE, it is useful to express it as a function of fundamental and observable cloud properties. In the infrared (LW), the altitude of clouds is one of the fundamental properties, together with their cover and opacity. The observations collected by the space-lidar CALIOP during the last decade allowed us to express the LW CRE using five cloud properties. We show that the LW CRE depends linearly on the cloud altitude. This linearity allows to decompose the variations of the LW CRE into contributions due to the five cloud properties. We observe that the cover of the opaque clouds drove the variations of the LW CRE during the last decade. The analysis of climate simulations performing the same approach by means of a lidar simulator shows that the variations of the LW CRE in the current climate are driven by the opaque cloud altitude, in disagreement with the observations. When we extend this analysis to the LW cloud feedback simulated in a future climate, we notice that they are also driven by the opaque cloud altitude. These results suggest that the space-lidar observations bring a strong observational constraint on the LW cloud feedbacks, which are one of the main sources of uncertainty in predicting future global average temperature evolution due to human activities.

Les systèmes de cartographie mobile sont de plus en plus utilisés pour la cartographie des scènes urbaines. La technologie de scan laser mobile (où le scanner est embarqué sur un véhicule) en particulier permet une cartographie précise de la voirie, la compréhension de la scène, la modélisation de façade, etc. Dans cette thèse, nous nous concentrons sur la détection de changement entre des nuages de points laser de cartographie mobile. Tout d'abord, nous étudions la détection des changements a partir de données RIEGL (scanner laser plan) pour la mise à jour de bases de données géographiques et l'identification d'objet temporaire. Nous présentons une méthode basée sur l'occupation de l'espace qui permet de surmonter les difficultés rencontrées par les méthodes classiques fondées sur la distance et qui ne sont pas robustes aux occultations et à l'échantillonnage anisotrope. Les zones occultées sont identifiées par la modélisation de l'état d'occupation de l'espace balayé par des faisceaux laser. Les écarts entre les points et les lignes de balayage sont interpolées en exploitant la géométrie du capteur dans laquelle la densité d'échantillonnage est isotrope. Malgré quelques limites dans le cas d'objets pénétrables comme des arbres ou des grilles, la méthode basée sur l'occupation est en mesure d'améliorer la méthode basée sur la distance point à triangle de façon significative. La méthode de détection de changement est ensuite appliquée à des données acquises par différents scanners laser et à différentes échelles temporelles afin de démontrer son large champs d'application. La géométrie d'acquisition est adaptée pour un scanner dynamique de type Velodyne. La méthode basée sur l'occupation permet alors la détection des objets en mouvement. Puisque la méthode détecte le changement en chaque point, les objets en mouvement sont détectés au niveau des points. Comme le scanner Velodyne scanne l'environnement de façon continue, les trajectoires des objets en mouvement peut être extraite. Un algorithme de détection et le suivi simultané est proposé afin de retrouver les trajectoires de piétons. Cela permet d'estimer avec précision la circulation des piétons des circulations douces dans les lieux publics. Les changements peuvent non seulement être détectés au niveau du point, mais aussi au niveau de l'objet. Ainsi nous avons pu étudier les changements entre des voitures stationnées dans les rues à différents moments de la journée afin d'en tirer des statistiques utiles aux gestionnaires du stationnement urbain. Dans ce cas, les voitures sont détectés en premier lieu, puis les voitures correspondantes sont comparées entre des passages à différents moments de la journée. Outre les changements de voitures, l'offre de stationnement et les types de voitures l'utilisant sont également des informations importantes pour la gestion du stationnement. Toutes ces informations sont extraites dans le cadre d'un apprentissage supervisé. En outre, une méthode de reconstruction de voiture sur la base d'un modèle déformable générique ajusté aux données est proposée afin de localiser précisément les voitures. Les paramètres du modèle sont également considérés comme caractéristiques de la voiture pour prendre de meilleures décisions. De plus, ces modèles géométriquement précis peuvent être utilisées à des fins de visualisation. Dans cette thèse, certains sujets liés à la détection des changements comme par exemple, suivi, la classification, et la modélisation sont étudiés et illustrés par des applications pratiques. Plus important encore, les méthodes de détection des changements sont appliquées à différentes géométries d'acquisition de données et à de multiples échelles temporelles et au travers de deux stratégies: “bottom-up” (en partant des points) et “top-down” (en partant des objets) / Mobile mapping systems are increasingly used for street environment mapping, especially mobile laser scanning technology enables precise street mapping, scene understanding, facade modelling, etc. In this research, the change detection from laser scanning point clouds is investigated. First of all, street environment change detection using RIEGL data is studied for the purpose of database updating and temporary object identification. An occupancy-based method is presented to overcome the challenges encountered by the conventional distance-based method, such as occlusion, anisotropic sampling. Occluded areas are identified by modelling the occupancy states within the laser scanning range. The gaps between points and scan lines are interpolated under the sensor reference framework, where the sampling density is isotropic. Even there are some conflicts on penetrable objects, e.g. trees, fences, the occupancy-based method is able to enhance the point-to-triangle distance-based method. The change detection method is also applied to data acquired by different laser scanners at different temporal-scales with the intention to have wider range of applications. The local sensor reference framework is adapted to Velodyne laser scanning geometry. The occupancy-based method is implemented to detection moving objects. Since the method detects the change of each point, moving objects are detect at point level. As the Velodyne scanner constantly scans the surroundings, the trajectories of moving objects can be detected. A simultaneous detection and tracking algorithm is proposed to recover the pedestrian trajectories in order to accurately estimate the traffic flow of pedestrian in public places. Changes can be detected not only at point level, but also at object level. The changes of cars parking on street sides at different times are detected to help regulate on-street car parking since the parking duration is limited. In this case, cars are detected in the first place, then they are compared with corresponding ones. Apart from car changes, parking positions and car types are also important information for parking management. All the processes are solved in a supervised learning framework. Furthermore, a model-based car reconstruction method is proposed to precisely locate cars. The model parameters are also treated as car features for better decision making. Moreover, the geometrically accurate models can be used for visualization purposes. Under the theme of change detection, related topics, e.g. tracking, classification, modelling, are also studied for the reason of practical applications. More importantly, the change detection methods are applied to different data acquisition geometries at multiple temporal-scales. Both bottom-up (point-based) and top-down (object-based) change detection strategies are investigated

As condições climáticas do Brasil aliadas ao desenvolvimento tecnológico favorecem a obtenção de sucessivos incrementos em produção florestal e estimulam a expansão de área cultivada com povoamentos voltados para a produção madeireira. Com o objetivo de contribuir para o processo de quantificação das florestas plantadas em uma escala regional, este estudo propõe utilizar informações combinadas de imagens de satélites e dados obtidos do LiDAR (Light Detecting and Ranging) para a construção de modelos determinísticos capazes de distinguir em duas categorias de idade agrupamentos de florestas plantadas no Vale do Paraíba, estado de São Paulo. A primeira etapa constitui utilizar informações de parcelas de campo como resposta para modelos gerados com variáveis de escaneamento a laser aeroembarcado (ALS) e extrapolar os parâmetros para toda a região da plantação; em um segundo momento, utilizar as informações extrapoladas para gerar um modelo composto por variáveis de índice de vegetação (IV) calculados das imagens de satélite. As informações LiDAR (Light Detecting and Ranging) foram obtidas de sete fazendas da região do Vale do Paraíba, estado de São Paulo, em 2012, mesmo ano em que foram coletados os dados das parcelas de campo dos inventários florestais e que as imagens foram obtidas pela constelação de satélites RapidEye. Como variáveis de dados ALS foram utilizados o cálculo de todos os pontos por célula de 5 x 5 m avaliados, alturas máxima, mínima, média, desvio padrão e percentis de altura, calculados pelo programa de análise de dados LASTools®. Foram incluídas também métricas de diferença de alturas do percentil 90 e o percentil 10 (p9010) e a medida dessa diferença relativa à altura do percentil 90 (p9010r). Na modelagem dos dados LiDAR para imagens de satélite foram utilizadas como variáveis, de forma individual ou conjuntamente, os índices NDVI, NDVI705, EVI, GNDVI, SAVI, Red-Green ratio e SRI. Os modelos foram avaliados quanto ao seu desempenho no coeficiente de determinação (R2) e na raíz do erro quadrático médio (RMSE) e em uma análise final predizendo as fazendas em categorias de idade jovem e maduro. O modelo com melhores estimativas (R2 e RMSE) para idade na primeira etapa foi o que possuía variáveis Hp90 e Hp9010r, com R2=0,85 e RMSE=11,736 meses, e para a segunda etapa foi o modelo contendo como variáveis os índices de vegetação NDVI705, Red-Green índex e SAVI, com R2=0,49 e RMSE=0,378 meses. Apesar dos resultados melhores, o modelo contendo índices de vegetação GNDVI e Red-Green índex foi o que melhor representou a distribuição das florestas quanto a sua maturidade. / Brazil\'s climate conditions combined with the technological development promote the obtaining of successive increments in forest production and stimulate the expansion of cultivated area with stands for timber production. In order to contribute to the process of quantification of planted forests at regional scale, this study proposes to use combined information from satellite images and data obtained from the LiDAR (Light Detecting and Ranging) for the construction of deterministic models able to distinguish two categories of age groupings of planted forests in the Paraíba Valley, State of São Paulo in Brazil. The first step is to use field plots information in response to models generated with airborne laser scanning (ALS) variables and extrapolate the parameters for the whole region of the plantation; in a second moment, use the information extrapolated to generate a model composed of vegetation index variables (IV) calculated from satellite images. The information LiDAR (Light Detecting and Ranging) were obtained from seven farms in the region of the Paraíba Valley, State of São Paulo, in 2012, the same year in which the data were collected from plots of field forest inventories and that the images were obtained by the RapidEye satellite constellation. As data variables ALS were used the calculation of all points by cell size of 5 x 5 m evaluated, maximum height, minimum, mean, standard deviation and height percentiles, calculated by the data analysis program called LASTools®. Also included height difference metrics 90th percentile and percentile 10th (p9010) and the extent of this difference relative of the 90th percentile (p9010r). In the modeling of data LiDAR data for satellite images were used as variables, individually or jointly, the NDVI index, NDVI705, EVI, GNDVI, SAVI, Red-Green index and SRI. The models were evaluated regarding their performance on the coefficient of determination (R2) and root mean square error (RMSE) and a final analysis predicting the farms into categories of age, young and mature. The model with best estimates (R2 and RMSE) for age at first stage was what possessed variables Hp90 and Hp9010r, with R2 = 0.85 and RMSE = 11.736 months, and the second stage was the model containing as variables the NDVI705 vegetation, Red-Green index and SAVI, with R2 = 0.49 and RMSE = 0.378 months. Despite the better results, the model containing GNDVI and Red-Green vegetation indices was the best represented distribution of forests about your maturity.

No âmbito das mudanças climáticas globais, a quantificação do estoque de carbono em povoamentos florestais tem recebido mais atenção, principalmente pelo fato das florestas exercerem um papel fundamental no equilíbrio do estoque de carbono global. Com o objetivo de contribuir para esse processo, a parte investigativa deste trabalho foi desenvolvida em duas etapas. A primeira etapa objetivou o ajuste de modelos alométricos para a estimativa do estoque de carbono presente na biomassa total (Ctotal), no lenho comercial (Cleco) e parte residual (Crds) (casca, folhas e galhos) em plantações de Eucalyptus spp. em nível de árvores, através de uma amostragem destrutivas de árvores, análise elementar do carbono em laboratório e medidas convencionais de inventário. A medição do diâmetro à altura do peito (DAP) e altura total das árvores em parcelas amostradas instaladas nos talhões onde as árvores foram coletadas para determinação direta de carbono também foi realizada. A segunda parte, consistiu na avaliação do uso da tecnologia LiDAR (Light Detection and Ranging) aerotransportada (Airborne LASER scanning) como uma alternativa eficiente e versátil para a estimativa do estoque de carbono total (Ctotal), no lenho comercial de toras (Cleco) e no resíduo da árvore (Crds) em nível de parcelas em plantações de Eucalyptus spp usando como base o estoque de carbono estimado na primeira fase. Os resultados obtidos encontram-se resumidos em dois artigos científicos. O primeiro artigo mostra que os modelos baseados no logaritmo do diâmetro à altura do peito (DAP) e da altura total da árvore (Ht) oferecem boas precisão e exatidão para estimar o estoque de carbono em nível de árvore. O segundo artigo, permitiu a determinação das melhores métricas LiDAR para o cálculo do teor total de carbono, tanto no carbono total, lenho comercial e nas partes residuais da árvore em nível de plantação. Esses resultados, bem como os indicadores estatísticos utilizados para avaliar a qualidade dos ajustes, são o cerne desta dissertação. / In the context of global climate change, the quantification of the carbon content in forest plantations have received great attention. This is because vegetation play an important role in the global carbon budget. This master thesis was developed in two main parts. The first part was to adjust allometric equations for the estimation of the carbon content at a tree level. This was performed for the above ground section (Ctotal), in commercial logs (Cleco) and residuals ( Crds) (e.g. bark, leaves and branches/twigs). The experiment was based on the destructive model of individual trees harvested in commercial plantations of Eucaliptus spp. The experiment encompasses both forest inventory and laboratory analyses procedures. Additionally, in-situ measurements such as the diameter at the breast height (DBH) and the total tree height were also performed. These sample plots were located in homogeneous forest units and close to the areas were the trees have been harvested. The second part of this master thesis was the evaluation of the airborne LiDAR technology as a tool for the retrieval of the above ground biomass (Ctotal), the carbon present in the commercial logs (Cleco) and residuals. This procedure was performed at the sample plots level. This procedure was based on the information provided in the first part. The results are presented as two scientific manuscripts. The first manuscript shows that allometric equations based on the log of the variables diameter at the breast height (DBH) and total tree height (Ht) were good predictors for the retrieval of the total carbon content at a tree level. The second manuscript allow the selection of the best LiDAR derived metrics for the retrieval of the total carbon content, either at above ground level, commercial logs and residual parts of the tree at a sample plots level. These results, as well as the statistical indicators for the adjustment of several statistical models is the core of this master thesis.

Three-dimensional laser scanning has revolutionized spatial data acquisition and can be completed from a variety of platforms including airborne (ALS), mobile (MLS), and static terrestrial (TLS) laser scanning. MLS is a rapidly evolving technology that provides increases in efficiency and safety over static TLS, while still providing similar levels of accuracy and resolution. The componentry that make up a MLS system are more parallel to Airborne Laser Scanning (ALS) than to that of TLS. However, achievable accuracies, precisions, and resolution results are not clearly defined for MLS systems. As such, industry professionals need guidelines to standardize the process of data collection, processing, and reporting. This thesis lays the foundation for MLS guidelines with a thorough review of currently available literature that has been completed in order to demonstrate the capabilities and limitations of a generic MLS system. A key difference between MLS and TLS is that a mobile platform is able to collect a continuous path of geo-referenced points along the navigation path, while a TLS collects points from many separate reference frames as the scanner is moved from location to location. Each individual TLS setup must be registered (linked with a common coordinate system) to adjoining scan setups. A study was completed comparing common methods of TLS registration and geo-referencing (e.g., target, cloud-cloud, and hybrid methods) to assist a TLS surveyor in deciding the most appropriate method for their projects. Results provide insight into the level of accuracy (mm to cm level) that can be achieved using the various methods as well as the field collection and office processing time required to obtain a fully geo-referenced point cloud. Lastly, a quality assurance methodology has been developed for any form of LiDAR data to verify both the absolute and relative accuracy of a point cloud without the use of retro-reflective targets. This methodology incorporates total station validation of a scanners point cloud to compare slopes of common features. The comparison of 2D slope features across a complex geometry of cross-sections provides 3D positional error in both horizontal and vertical component. This methodology lowers the uncertainty of single point accuracy statistics for point clouds by utilizing a larger portion of a point cloud for statistical accuracy verification. This use of physical features for accuracy validation is particularly important for MLS systems because MLS systems cannot produce sufficient resolution on targets for accuracy validation unless they are placed close to the vehicle. / Graduation date: 2012

Due to the unique environmental conditions and different feedback mechanisms, the Arctic region is especially sensitive to climate changes. The influence of clouds on the radiation budget is substantial, but difficult to quantify and parameterize in models. In the framework of the PhD, elastic backscatter and depolarization lidar observations of Arctic clouds were performed during the international Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR) from Svalbard in March and April 2007. Clouds were probed above the inaccessible Arctic Ocean with a combination of airborne instruments: The Airborne Mobile Aerosol Lidar (AMALi) of the Alfred Wegener Institute for Polar and Marine Research provided information on the vertical and horizontal extent of clouds along the flight track, optical properties (backscatter coefficient), and cloud thermodynamic phase. From the data obtained by the spectral albedometer (University of Mainz), the cloud phase and cloud optical thickness was deduced. Furthermore, in situ observations with the Polar Nephelometer, Cloud Particle Imager and Forward Scattering Spectrometer Probe (Laboratoire de Météorologie Physique, France) provided information on the microphysical properties, cloud particle size and shape, concentration, extinction, liquid and ice water content. In the thesis, a data set of four flights is analyzed and interpreted. The lidar observations served to detect atmospheric structures of interest, which were then probed by in situ technique. With this method, an optically subvisible ice cloud was characterized by the ensemble of instruments (10 April 2007). Radiative transfer simulations based on the lidar, radiation and in situ measurements allowed the calculation of the cloud forcing, amounting to -0.4 W m-2. This slight surface cooling is negligible on a local scale. However, thin Arctic clouds have been reported more frequently in winter time, when the clouds' effect on longwave radiation (a surface warming of 2.8 W m-2) is not balanced by the reduced shortwave radiation (surface cooling). Boundary layer mixed-phase clouds were analyzed for two days (8 and 9 April 2007). The typical structure consisting of a predominantly liquid water layer on cloud top and ice crystals below were confirmed by all instruments. The lidar observations were compared to European Centre for Medium-Range Weather Forecasts (ECMWF) meteorological analyses. A change of air masses along the flight track was evidenced in the airborne data by a small completely glaciated cloud part within the mixed-phase cloud system. This indicates that the updraft necessary for the formation of new cloud droplets at cloud top is disturbed by the mixing processes. The measurements served to quantify the shortcomings of the ECMWF model to describe mixed-phase clouds. As the partitioning of cloud condensate into liquid and ice water is done by a diagnostic equation based on temperature, the cloud structures consisting of a liquid cloud top layer and ice below could not be reproduced correctly. A small amount of liquid water was calculated for the lowest (and warmest) part of the cloud only. Further, the liquid water content was underestimated by an order of magnitude compared to in situ observations. The airborne lidar observations of 9 April 2007 were compared to space borne lidar data on board of the satellite Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). The systems agreed about the increase of cloud top height along the same flight track. However, during the time delay of 1 h between the lidar measurements, advection and cloud processing took place, and a detailed comparison of small-scale cloud structures was not possible. A double layer cloud at an altitude of 4 km was observed with lidar at the West coast in the direct vicinity of Svalbard (14 April 2007). The cloud system consisted of two geometrically thin liquid cloud layers (each 150 m thick) with ice below each layer. While the upper one was possibly formed by orographic lifting under the influence of westerly winds, or by the vertical wind shear shown by ECMWF analyses, the lower one might be the result of evaporating precipitation out of the upper layer. The existence of ice precipitation between the two layers supports the hypothesis that humidity released from evaporating precipitation was cooled and consequently condensed as it experienced the radiative cooling from the upper layer. In summary, a unique data set characterizing tropospheric Arctic clouds was collected with lidar, in situ and radiation instruments. The joint evaluation with meteorological analyses allowed a detailed insight in cloud properties, cloud evolution processes and radiative effects. / Die Arktis mit ihren speziellen Umweltbedingungen ist besonders empfindlich gegenüber Klimaveränderungen. Dabei spielen Wolken eine große Rolle im Strahlungsgleichgewicht, die aber nur schwer genau bestimmt und in Klimamodellen dargestellt werden kann. Die Daten für die Promotionsarbeit wurden im Frühjahr 2007 bei Flugzeug-Messungen von Wolken über dem Arktischen Ozean von Spitzbergen aus erhoben. Das dafür verwendete Lidar (Licht-Radar) des Alfred-Wegener-Instituts lieferte ein höhenaufgelöstes Bild der Wolkenstrukturen und ihrer Streu-Eigenschaften, andere Messgeräte ergänzten optische sowie mikrophysikalische Eigenschaften der Wolkenteilchen (Extinktion, Größenverteilung, Form, Konzentration, Flüssigwasser- und Eisgehalt, Messgeräte vom Laboratoire de Météorologie Physique, France) und Strahlungsmessungen (Uni Mainz). Während der Messkampagne herrschte Nordwind vor. Die untersuchten Luftmassen mit Ursprung fern von menschlichen Verschmutzungsquellen war daher sehr sauber. Beim Überströmen der kalten Luft über den offenen warmen Arktischen Ozean bildeten sich in der Grenzschicht (ca. 0-1500 m Höhe) Mischphasenwolken, die aus unterkühlten Wassertröpfchen im oberen Bereich und Eis im unteren Bereich der Wolken bestehen. Mit den Flugzeug-Messungen und numerischen Simulationen des Strahlungstransports wurde der Effekt einer dünnen Eiswolke auf den Strahlungshaushalt bestimmt. Die Wolke hatte lokal eine geringe Abkühlung der Erdoberfläche zur Folge. Ähnliche Wolken würden jedoch im Winter, wenn keine Sonnenstrahlung die Arktis erreicht, durch den Treibhauseffekt eine nicht vernachlässigbare Erwärmung der Oberfläche verursachen. Die Messungen der Mischphasenwolken wurden mit einem Wettervorhersagemodell (ECMWF) verglichen. Für die ständig neue Bildung von flüssigen Wassertropfen im oberen Teil der Wolke ist das Aufsteigen von feuchten Luftpaketen nötig. Während einer Messung wurden entlang der Flugstrecke verschiedene Luftmassen durchflogen. An der Luftmassengrenze wurde eine reine Eiswolke inmitten eines Mischphasen-Systems beobachtet. Die Messungen zeigen, dass das Mischen von Luftmassen den Nachschub an feuchter Luft blockiert, was unmittelbare Auswirkungen auf die thermodynamische Phase des Wolkenwassers hat. Weiterhin wurde bestimmt, wie groß die Abweichungen der Modellrechnungen von den Messungen bezüglich Wassergehalt und der Verteilung von Flüssigwasser und Eis waren. Durch die vereinfachte Wolken-Parameterisierung wurde die typische vertikale Struktur von Mischphasenwolken im Modell nicht wiedergegeben. Die flugzeuggetragenen Lidar-Messungen vom 9. April 2007 wurden mit Lidar-Messungen an Bord des Satelliten CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) verglichen. Die Messungen zeigten beide eine ansteigende Wolkenobergrenze entlang desselben Flugwegs. Da die Messungen jedoch nicht genau gleichzeitig durchgeführt wurden, war wegen Advektion und Prozessen in den Wolken kein genauer Vergleich der kleinskaligen Wolkenstrukturen möglich. Außerdem wurde eine doppelte Wolkenschicht in der freien Troposphäre (4 km Höhe) analysiert. Die Wolke bestand aus zwei separaten dünnen Schichten aus flüssigem Wasser (je 150 m dick) mit jeweils Eis darunter. Die untere Schicht entstand wahrscheinlich aus verdunstetem Eis-Niederschlag. Diese feuchte Schicht wurde durch die Abstrahlung der oberen Wolkenschicht gekühlt, so dass sie wieder kondensierte. Solche Wolkenformationen sind in der Arktis bisher vor allem in der Grenzschicht bekannt. Ein einzigartiger Datensatz von arktischen Wolken wurde mit einer Kombination verschiedener Flugzeug-Messgeräte erhoben. Zusammen mit meteorologischen Analysen konnten für verschiedene Fallstudien Wolkeneigenschaften, Entwicklungsprozesse und Auswirkungen auf den Strahlungshaushalt bestimmt werden.