Above-Ground Biomass (AGB) assessment using remote sensing has been an active area of research since the 1970s. However, improvements in the reported accuracy of wide scale studies remain relatively small. Therefore, there is a need to improve error analysis to answer the question: Why is AGB assessment accuracy still under doubt? This project aimed to develop and implement a systematic quantitative methodology to analyse the uncertainty of remotely sensed AGB, including all perceptible error types and reducing the associated costs and computational effort required in comparison to conventional methods. An accuracy prediction tool was designed based on previous study inputs and their outcome accuracy. The methodology used included training a neural network tool to emulate human decision making for the optimal trade-off between cost and accuracy for forest biomass surveys. The training samples were based on outputs from a number of previous biomass surveys, including 64 optical data based studies, 62 Lidar data based studies, 100 Radar data based studies, and 50 combined data studies. The tool showed promising convergent results of medium production ability. However, it might take many years until enough studies will be published to provide sufficient samples for accurate predictions. To provide field data for the next steps, 38 plots within six sites were scanned with a Leica ScanStation P20 terrestrial laser scanner. The Terrestrial Laser Scanning (TLS) data analysis used existing techniques such as 3D voxels and applied allometric equations, alongside exploring new features such as non-plane voxel layers, parent-child relationships between layers and skeletonising tree branches to speed up the overall processing time. The results were two maps for each plot, a tree trunk map and branch map. An error analysis tool was designed to work on three stages. Stage 1 uses a Taylor method to propagate errors from remote sensing data for the products that were used as direct inputs to the biomass assessment process. Stage 2 applies a Monte Carlo method to propagate errors from the direct remote sensing and field inputs to the mathematical model. Stage 3 includes generating an error estimation model that is trained based on the error behaviour of the training samples. The tool was applied to four biomass assessment scenarios, and the results show that the relative error of AGB represented by the RMSE of the model fitting was high (20-35% of the AGB) in spite of the relatively high correlation coefficients. About 65% of the RMSE is due to the remote sensing and field data errors, with the remaining 35% due to the ill-defined relationship between the remote sensing data and AGB. The error component that has the largest influence was the remote sensing error (50-60% of the propagated error), with both the spatial and spectral error components having a clear influence on the total error. The influence of field data errors was close to the remote sensing data errors (40-50% of the propagated error) and its spatial and non-spatial Overall, the study successfully traced the errors and applied certainty-scenarios using the software tool designed for this purpose. The applied novel approach allowed for a relatively fast solution when mapping errors outside the fieldwork areas.

As regiões de cultivo de eucalipto apresentam um grande número de variações ambientais em nível microrregional, como pode ser facilmente constatado quando se observam as diferenças expressivas entre as produtividades florestais de cada área. No entanto, para se avaliar um ambiente, é necessário identificar segmentos específicos dentro de uma paisagem, tratando-se de uma propriedade florestal e, dentro desse estudo, buscar a compreensão das interações que aí se processam. Este trabalho contribui para entender o efeito da face de exposição solar no crescimento de plantios comerciais de Eucalyptus. A proposta metodológica apresentada leva em consideração o conhecimento do meio físico - tendo como base a fisiografia para distinção das faces de exposição solar- além disso, a interação dos fatores fisiográficos com os fatores biológicos são discutidos para subsidiar a tomada de decisão. A acentuada interação genótipo x ambiente presente em muitas culturas faz com que estudos de adaptabilidade a ambientes específicos sejam parte integrante dos programas de pesquisa florestal. A resposta diferenciada dos genótipos a ambientes favoráveis e desfavoráveis pode auxiliar o gestor florestal na alocação assertiva dos materiais genéticos para maximizar a produtividade. O escaneamento a laser aerotransportado, ferramenta de uso precoce no Brasil, é um sensor óptico ativo que mede a distância até os objetos-alvo e foi utilizado para a obtenção da altura das árvores. A área de estudo está localizada na região sudoeste do estado de São Paulo. Dentre as métricas disponíveis do processamento utilizou o percentil 90 de altura para estimar a altura de plantios comerciais homogêneos de Eucalyptus. Elaborou-se a análise de variância considerando um delineamento fatorial contemplando a face de exposição solar (norte e sul) e o material genético (clones comerciais), além da interação entre ambos para observar o efeito da face no crescimento em altura do povoamento. Para florestas abaixo de quatro anos de idade observou-se que os plantios de face sul cresceram menos que os da face norte. Para florestas acima de 5 anos essa diferença entre face continua, contudo, quando concluído o desdobramento da interação fatorial observou-se que os materiais genéticos plantados em face norte não diferem entre si, mas a diferença se mantém para florestas em face sul. / The eucalyptus cultivation regions boast a large number of environmental variables in micro-regional level, as can easily be seen when studying the expressive differences between the productivity of each forest area. To evaluate an environment, however, it is necessary to identify specific segments within a landscape with regards to a forest property and within that landscape study to seek the understanding of the interactions that takes place in the process. This work contributes to a better understanding of the effect of the aspect on growth in commercial plantations of Eucalyptus. The methodological approach presented in this work takes into account the knowledge of the physical environment, based on physiography, for distinction of aspect on environments, in addition to showing the interaction of physiographic factors with biological factors to support the decision-making process. The sharp interaction genotype x environment present in many cultures leads to studies of adaptability to specific environments to become integral parts of forestry research programs. The differentiated response of genotypes to favorable and unfavorable environments can assist forest managers in the allocation of assertive genetic materials to maximize productivity. The airborne laser scanning, which is an early tool used in Brazil, is an active optical sensor that measures the distance to the target objects, was used to obtain the height of the trees. The study area is located in the southwestern region of the State of São Paulo in Brazil. Among the available processing metrics, it was used 90 percentiles in height to estimate the height of homogeneous commercial plantations of Eucalyptus. A variance analysis was devised considering a factorial design contemplating the aspect (North and South) and genetic material (commercial clones), besides the interaction between both to observe the effect of the exposure on the height growth of the settlement. To forests below four years of age, it was observed that the plantations of the South exposure grow less than the north exposure. For forests above five years, this difference between aspect continues, however, when the deployment of factorial interactions is done, it\'s observed that the genetic materials planted in the north exposure do not differ with each other, but the difference stands within forests in the South exposure.

The use of digital three-dimensional (3D) data has increased over the last two decades as private and public firms have begun to realize its utility. Mobile Terrestrial Laser Scanning (MTLS) or Mobile Mapping Systems (MMS), which utilizes LiDAR (Light Detection and Ranging) data collection from a moving platform along with advances in positioning systems—e.g., Global Navigation Satellite Systems (GNSS), Inertial Navigation Systems (INS), and Distance Measurement Instruments (DMIs)—have paved the way for efficient, abundant, and accurate 3D data collection. Validation and control targets are vital to ensure relative and/or absolute accuracy for MTLS projects. The focus of this dissertation is to evaluate several types of targets and the positional spacing of said targets for MTLS.<div><br></div><div>A mostly planar two-dimensional (2D) targeting system (painted target on ground) is commonly used to constrain, register, and validate the 3D point clouds from MTLS. In this dissertation, 3D objects—a sphere and a cube—were evaluated with varied angles of incidence and point densities as more appropriate alternatives to constrain and validate the 3D MTLS point clouds. Next, a planar circular 2D target—with the use of the raw intensity of the LiDAR pulse as another measured dimension—was evaluated as a proof of concept to also constrain and validate 3D LiDAR data. A third and final component of this dissertation explored analyses of INS data to determine the positional spacing of control and validation targets in MTLS projects to provide maximum accuracy for all data points.<br></div>

A quantificação de recursos florestais é usada para fins diversos nas ciências naturais, e depende da obtenção de dados de campo de forma precisa e rápida, e o inventário florestal tem se valido principalmente de trabalho humano manual para este fim. A tecnologia LiDAR, baseada em sistemas a laser, permite a coleta desses dados por meio da representação tridimensional do ambiente e a geração de informações espacialmente precisas dos objetos que o compõe. O sistema de varredura laser terrestre (terrestrial laser scanning - TLS) aplica essa tecnologia sob abordagem terrestre, e assim pode ser usada na representação 3D de florestas e ambientes naturais. Devido a crescente número de estudos nesse tópico atualmente o sistema TLS é capaz de fornecer métricas florestais básicas com elevada exatidão, como densidade de plantio e diâmetro à altura do peito, além de informações não obtidas pelo inventário florestal padrão, como estimativa da biomassa e índice de área foliar, entre outros. Este trabalho tem por objetivo a avalição da capacidade do sistema TLS em fornecer com exatidão métricas de árvores individuais selecionadas em dois povoamentos florestais localizados no sudeste do Brasil. Árvores de Eucalyptus sp. (n = 6) e Pinus elliottii var. elliottii (n = 5) foram submetidas à varredura e os valores obtidos pelo mapeamento 3D foram comparados com dados medidos em campo manualmente. Os resultados encontrados mostram que o algoritmo empregado na filtragem dos troncos foi eficiente no isolamento dos fustes de árvores individuais até a altura total das árvores amostradas, enquanto que o algoritmo para modelagem do tronco filtrado foi capaz de fornecer medidas de diâmetro até 50% da altura total das amostras. A exatidão das medidas de DAP pelos dados TLS foi de 0,91 cm e 2,77 cm (REQM) para Eucalyptus e Pinus, respectivamente. Os diâmetros ao longo do fuste tiveram mais exatidão no Eucalyptus (REQM = 2,75 cm e r = 0,77) do que no Pinus (REQM = 3,62 cm e r = 0,86), resultados condizentes com os encontrados em literatura. A exatidão da estimativa dos diâmetros diminuiu ao longo do fuste. O autor sugere que a influência de vento forte no momento da varredura pode ter interferido na qualidade das nuvens de pontos em relação a ruídos e na exatidão dos modelos de obtenção de diâmetros. A partir destes resultados conclui-se que, para as características ambientais e parâmetros de varreduras apresentados, o sistema TLS foi capaz de fornecer dados com exatidão aceitável, e mais estudos devem ser conduzidos buscando o entendimento e mitigação de efeitos que podem dificultar a obtenção de dados precisos nos estratos superiores do dossel florestal. / Forest resources assessment is used for diverse purposes on natural sciences, and relies on field data acquisition in fast and precise ways, and forest inventory has been relying mainly on manual human labor for that. LiDAR technology, which is based on a laser system, allows for these data acquisition through 3D representation of surroundings and the generation of espacially precise information about the objetcs within. Terrestrial laser scanning - TLS - applies this technology in a land approach, thus it can be used on the 3D representation of forests and natural scenes. Due to increasing number of studies on this subject nowadays TLS system is capable of giving basic forest metrics with high precision, as for plant density and diameter at breast height, besides information not obtained by standard inventory procedures, as biomass estimation and leaf área index, among others. This work aims the assessment of TLS capability on giving precise metrics of individual trees located at two forest stands in southeastern Brazil. Trees of Eucalyptus sp. (n = 6) and Pinus elliottii var. elliottii (n = 5) were scanned and the numbers obtained by 3D mapping were compared to manually measured field data. The results found show that the algorithms used on trunk filtration were efficient on individual trees stem isolation until total height of measured trees, while the trunk modelling algorithm was capable of giving diameters until 50% of samples total height. The precision of DBH measurements by TLS data was 0,91 cm and 2,77 cm (RMSE) for Eucalyptus and Pinus, respectivelly. Diameters along the stem were more preciselly estimated for Eucalytus trees (RMSE = 2,75 cm and r = 0,77) than for Pinus trees (RMSE = 3,62 cm and r = 0,86), results consistente with literature. The precision of diameters estimation diminished along the stem. The author suggests that the influence of intense wind by the time of scanning can have interfered on cloud point quality in the terms of noises and thus on the precision of diameter estimation modelling. From these results one can conclude that, considering the environmental aspects and scanning parameters presented, TLS system was capable on giving data with acceptable precision, and more studies must be carried searching for understanding and mitigation of effects that can difficult precise data acquisition on upper forest strata.

Accelerated soil erosion and the subsequent decline in soil depth has negative environmental, and consequently financial, impacts that have implications across all land cover classifications and scales of land management. Ironically, although attempts to quantify soil erosion nationally have illustrated that soil erosion can occur in the UK, understanding whether or not the UK has a soil erosion problem still remains a question to be answered. Accurately quantifying rates of soil erosion requires capturing both the volumetric nature of the visible, fluvial pathways and the subtle nature of the less-visible, diffuse pathways, across varying spatial and temporal scales. Accordingly, as we move towards a national-scale understanding of soil erosion in the UK, this thesis aims to explore some of the multiple techniques available for developing an understanding of soil erosion in the UK. The thesis first explored the information content of existing UK-based soil erosion studies, ascertaining the extent to which these existing data and methodological approaches can be used to develop an empirically derived understanding of soil erosion in the UK. The second research chapter then assessed which of two proximal sensing technologies, Terrestrial Laser Scanning and Structure-from-Motion Multi-view Stereo (SfM-MVS), is best suited to a cost-effective, replicable and robust assessment of soil erosion within a laboratory environment. The final research chapter built on these findings, using both Rare Earth Oxide tracers and SfM-MVS to elucidate retrospective information about sediment sources under changing soil erosion conditions, also within a laboratory environment Given the biased nature of the soil erosion story presented within the existing soil erosion research in the UK, it is impossible to ascertain if the frequency and magnitude of soil erosion events in the UK are problematic. However, this study has also identified that without ‘true’ observations of soil loss i.e. collection of sediment leaving known plot areas, proxies, such as the novel techniques presented in the experimental work herein and the methods used in the existing landscape scale assessments of soil erosion as included in the database chapter, are not capable of providing a complete assessment of soil erosion rates. However, this work has indicated that despite this limitation, each technique can present valuable information on the complex and spatially variable nature of soil erosion and associated processes, across different observational environments and scales.

This dissertation presents techniques of three-dimensional microscopy. First, an economical method of microscopic image formation that employs a raster-scanning laser beam focused on a sample, while non-imaging detector receives the scattered light is presented. The images produced by this method are analogous to the scanning electron microscopy with visible effects of shadowing and reflection. Compared to a conventional wide-field imaging system, the system allows for a greater flexibility, as the variety of optical detectors, such as PMT and position-sensitive quadrant photodiode can be used to acquire images. The system demonstrates a simple, low-cost method of achieving the resolution on the order of a micron. A further gain in terms of resolution and the depth of focus by using Bessel rather than Gaussian beams is discussed. Then, a phase-imaging technique to quantitatively study the three-dimensional structure of reflective and transmissive microscopic samples is presented. The method, based on the simultaneous dual-wavelength digital holography, allows for higher axial range at which the unambiguous phase imaging can be performed. The technique is capable of nanometer axial resolution. The noise level, which increases as a result of using two wavelengths, is then reduced to the level of a single wavelength. The method compares favorably to software unwrapping, as the technique does not produce non-existent phase steps. Curvature mismatch between the reference and object beams is numerically compensated. The 3D images of porous coal samples and SKOV-3 ovarian cancer cells are presented.

Since the texture of surfaces plays a key role in the shaping of many environmental processes, high resolution measurements are important to study these phenomena. Specifically, 3-D point cloud data is desirable to document river shape and evolution, surface roughness, and erosion-sedimentation processes. The best method of obtaining these measurements is using a terrestrial laser scanner. However, these are too expensive for limited-use experiments. Therefore, I developed a simple, affordable, and robust system used to acquire high resolution data relating to hydraulic and fluvial environments.

Reims Cathedral holds a great deal of significance for the history of Gothic architecture, as well as the larger history of France as the coronation church. Given the historic significance of Reims, it is not surprising that much scholarship has been dedicated to the building’s sculpture, glass, and architecture. Most studies dealing with the cathedral’s architecture are based on stylistic and archaeological analysis, augmented by the use of surviving documents related to the construction. Although much fruitful work has been done in this vein, important questions about the building’s chronology and design still remain unresolved. The extent to which the design of the cathedral was established at the start of its construction, for example, continues to be disputed. The most recent monograph on the cathedral, published by Alain Villes in 2009, suggests that dramatic revisions to the overall plan and elevation were introduced during the course of its construction, going beyond the alterations to the façade designs that many previous authors have noted, but his theses remain controversial. Subsequently, Robert Bork has produced geometric models of the cathedral, which suggest that its plan was more coherent and unified. Additionally, French archaeologist Walter Berry has conducted new excavations, which further reveal additional archaeological evidence not yet taken into account by other Reims scholars. My dissertation, “Measuring the Past: The Geometry of Reims Cathedral,” examines the architectural design from a geometric perspective, augmented by archaeological, stylistic, and historic evidence. The primary contribution that my dissertation makes to art history is the development of a new, modern plan of the cathedral. I developed this plan by taking thousands of measurements using handheld devices and laser mapping, which I then incorporated into a single data set. This work allowed Bork and me to further refine the underlying geometry that created the cathedral’s layout and proportions. This new plan indicates that a master plan devised by the first architect governed the whole church, with subsequent modifications affecting its articulation rather than its overall layout. In addition to explaining how this plan was originally conceived, my dissertation also examines the anomalies and mistakes made during construction, which at times forced minor deviations from the plan. Some of these building errors and the obvious attempts to correct them give clues to the order of construction, in addition to supporting the notion that the masons repeatedly returned to the uniform scheme. This allows me to reassess the scholarship written about the cathedral and the complex history of the building project, while resolving some of the disputes over the cathedral’s construction and design.

Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2008.

Low back pain represents a significant concern in the United States, with 70% of individuals experiencing symptoms at some point in their lifetime. Although the specific cause of low back pain remains unclear, symptoms have been strongly associated with degeneration of the intervertebral disc. Insufficient nutritional supply to the disc is believed to be a major mechanism for tissue degeneration. Understanding nutrients' transport in intervertebral disc is crucial to elucidate the mechanisms of disc degeneration, and to develop strategies for tissue repair (in vivo), and tissue engineering (in vitro). Transport in intervertebral disc is complex and involves a series of electromechanical, chemical and biological coupled events. Despite of the large amount of studies performed in the past, transport phenomena in the disc are still poorly understood. This is partly due to the limited number of available experimental techniques for investigating transport properties, and the paucity of theoretical or numerical methods for systematically predicting the mechanisms of solute transport in intervertebral disc. In this dissertation, a theoretical and experimental approach was taken in order to investigate the mechanisms of solute transport and binding interactions in intervertebral disc. New imaging techniques were developed for the experimental determination of diffusive and binding parameters in biological tissues. The techniques are based on the principle of fluorescence recovery after photobleaching, and allow the determination of the anisotropic diffusion tensor, and the rates of binding and unbinding of a solute to the extracellular matrix of a biological tissue. When applied to the characterization of transport properties of intervertebral disc, these methods allowed the establishment of a relationship between solute anisotropic and inhomogeneous diffusivity and the unique morphology of human lumbar annulus fibrosus. A mixture theory for charged hydrated soft tissues was presented as a framework for theoretical investigations on solute transport and binding interactions in cartilaginous tissues. Based on this theoretical framework and on experimental observations, a finite element model was developed to predict solute diffusive-convective-reactive transport in cartilaginous tissues. The numerical model was applied to simulate the effect of mechanical loading on solute transport and binding interactions in cartilage explants and intervertebral disc.