This study used airborne gravity data, the 2008 Earth Gravity Model (EGM08) and Shuttle Radar Topographic Mission (SRTM) digital elevation data in a ‘Remove-Compute-Restore’ process to determine absolute vertical reference system for Ethiopia. This gives a geopotential height at any isolated field point where there is a Global Navigation Satellite System (GNSS) measurement without reference to a vertical network or a regional datum point. Previously, height was determined conventionally by connecting the desired field point physically to a nearby bench mark of a vertical network using co-located measurements of gravity and spirit levelling. With the use of precise GNSS positioning and a gravity model this method becomes obsolesce. The new approach uses the ‘Remove-Restore’ process to eliminate longer to shorter wavelengths from the measured gravity data using EGM08 and geometrical and condensed gravity models of the SRTM data. This provides small, smooth and localised residuals so that the interpolation and integration involved is reliable and the Stokes-like integral can be legitimately restricted to a spherical cap. A very fast, stable and accurate computational algorithm has been formulated by combining ‘hedgehog’ and ‘multipoint’ models in order to make tractable an unavoidably huge computational task required to remove the effects of about 1.5 billion! SRTM topographic mass elements representing Ethiopia and its immediate surroundings at 92433 point airborne gravity observations. The compute stage first uses an iterative Fast Fourier Transform (FFT) to predict residual gravity at aircraft height as a regular grid on to the surface of the ellipsoidal Earth and then it used a Fourier operation equivalent to Stokes’ integral to transform the localised gravity disturbance to residual potential. The restore process determines the geopotential number on or above the Earth’s surface where practitioners need it by restoring the potential effects of the removed masses. The accuracy of the geopotential number computed from gravity and topography was evaluated by comparing it with the one derived directly from EGM08 and precise geodetic levelling. The new model is in a good agreement across 100 km baseline with a standard deviation of 56 10−2 2 −2 × m s and 39 10−2 2 −2 × m s relative to EGM08 and levelling, respectively ( 10−2 2 −2 m s is approximately equivalent to 1mm of height). The new method provides an absolute geopotential height of a point on or above the Earth’s surface in a global sense by interpolating from geopotential models prepared as the digital grids carried in a chip for use with the GNSS receiver in the field.

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The Central Multiplexer is a versatile data multiplexer designed to address emerging test requirements for recording data from many sources on digital rotary head recorders at high data rates. A modular design allows easy reconfiguration for airborne or laboratory use; simultaneous data input from 63 sources of data in any combination of PCM commutators, ARINC 429 buses, ARINC 629 buses, MIL- STD-1553 buses, and general-purpose high-speed serial data packets; simultaneous, independent programmable outputs to high-speed digital data recorders, quick-look displays, and engineering monitor and analysis systems; and setup and control from a remote panel, a dumb terminal, a laptop personal computer, a standalone test system, or a large control computer.

Construction and Demolition (C&D) processing and recycling facilities accept waste materials that are generated during construction and demolition activities. The processing facility sorts, processes, and transfers the material to another operation. A consequence of these processes is the generation of particulate matter.This study involved quantifying and qualifying airborne particulates at three C&D processing facilities. Active stationary particulate sampling devices were employed to quantify the particle sizes of interest. Results were compared to United States Environmental Protection Agency (EPA) National Ambient Air Quality Standards(NAAQS) and United States Occupational Safety and Health Administration (OSHA)standards.The results from this study are not valid for determination of compliance with NAAQS or OSHA standards. However, the data indicate that C&D processing facilities may exceed current NAAQS at certain locations, but do not exceed OSHA standards. These results can be used by the industry as an engineering tool to reduce airborne particulate levels during normal operations of C&D facilities.

Modelling of selected forest geometric parameters from airborne laser scanning data Abstract The main aim of this work is to approximate the shape of a tree crown with mathematically describable 3D shape based on airborne laser scanning (ALS) data. And consequently derive geometrical parameters describing the tree from this model. Included in the work is a custom designed algorithm based on angular segmentation. Measured results of this algorithm are then compared to an algorithm based on RANSAC and field measurement. The first part of this work describes airborne laser scanning, its use to derive characteristics of forest stands and individual trees and the theory of tree crown modelling. The next part contains a description of both algorithms and presentation of results and field measurements. The conclusion summarizes and evaluates the outputs of the custom angular segmentation algorithm and discusses its possible modifications. Keywords: airborne laser scanning, tree height, crown width, crown height, crown cover, crown volume, crown shape, RANSAC

Coregistration of airborne laser scanning data and aerial images Abstract This thesis is dealing with the co-registration of aerial laser scanning and aerial images. Theoretical part with research of current methods puts emphasis on methods suitable for remote sensing datasets. Part of the thesis is about pre-processing data for co-registration and DSM production. Selection of co- registration methods for remote sensing is based on previous researches. Selected co-registration methods are applied on datasets from EuroSDR research project and ČÚZK dataset. Application is realised by programming codes and functions that were created for this purpose in Matlab. Possibilities of usage, advantages and disadvantages of methods are being mentioned in the next parts of the thesis with emphasis on time of the computation and final accuracy. The function programmed in Matlab allows comparison of co-registration methods and allows the user to decide which of the co- registration methods to use on input datasets. Discussion section describes the possibilities of method extensions and problematic parts across the whole co-registration process. Keywords: co-registration, laser, scanning, images, photogrammetry, remote sensing, coordinate, image matching.

This thesis presents two new algorithms for doing constrained Magnetotelluric (MT) inversion based on an existing Occam 2D inversion program. The first algorithm includes borehole resistivity logs as prior information to constrain resistivity directly in the vicinity of boreholes. The second algorithm uses reflection seismic data as prior constraints to transfer structural information from seismic images to 2D resistivity models. These two algorithms are efficient (proved through tests of synthetic examples) and widely applicable. In this thesis, they have been successfully applied to the COSC (Collisional Orogeny in the Scandinavian Caledonides) MT data. The COSC project aims to study the mountain belt dynamics in central Sweden by drilling two 2.5 km deep boreholes. MT data were collected to locate the main décollement that separates the overlying Caledonian allochthons and the underlying Precambrian basement, as the main décollement is associated with very conductive Alum shale. The previous interpretation based on part of the COSC seismic profile (CSP) was that the main décollement was located along a reflection with depth of 4.5 km underneath Åre and ~3 km underneath Mörsil, in central Jämtland. The MT resistivity model reveals a very conductive layer in the central and western parts of the profile, the top of which coincides with the first seismic reflection. This means that the first conductive alum shale layer occurs at less than 1 km depth, supporting a new interpretation of the main décollement at shallower depth. In a re-interpretation of the CSP data based on the MT model, the main décollement occurs a few hundred metres below the top of the conductor and is coincident with a laterally continuous seismic reflection. Further, the overlying seismic reflections resemble imbricated alum shale of the Lower Allochthon. MT inversion using seismic constraints from CSP gives further support to the new interpretation. Moreover, MT investigations were conducted in the Alnö alkaline and carbonatite ring-intrusion complex in Sweden. 2D and 3D resistivity models inverted from MT data together with resistivity and porosity laboratory measurements delineate a fossil magma chamber as a resistive anomaly surrounded by electrically conductive up-doming and ring-shaped faults and fractures.

Le travail de recherche présenté dans cette thèse a pour objectif principal l’évaluation de l’intérêt de la télédétection active par lidar, à partir de plateformes spatiales, pour le suivi des systèmes forestiers à l’échelle de la planète. La forêt est l’un des principaux modérateurs du climat par son action sur les grands cycles biogéochimiques dont les plus importants sont les cycles de l’eau et du gaz carbonique. Cet environnement est néanmoins très mal documenté à l’échelle globale car il n’est pas toujours facile d’accès. Les observations aéroportées et spatiales, par télédétection, sont donc les approches les mieux adaptées afin de donner accès aux différentes échelles caractéristiques des processus d’interaction entre le milieu atmosphérique et la forêt. Afin de valoriser la télédétection par lidar, il a été nécessaire de construire une base de données représentative de différents environnements forestiers, allant de la forêt gérée à la forêt tropicale primaire. Ces données ont été obtenues suite à plusieurs campagnes utilisant un nouveau démonstrateur lidar, le système ULICE (Ultraviolet LIdar for Canopy Experiment). Elles ont permis d’évaluer les différentes sources d’incertitudes liées à la mesure pour l’extraction des paramètres forestiers pertinents (i.e. hauteur des arbres, quantité de biomasse aérienne, indice de couverture foliaire, …). Cette évaluation a été possible suite au développement d’un simulateur numérique qui prend en compte les caractéristiques de la surface, de l’atmosphère, de l’instrumentation lidar et d’orbitographie du satellite. On montre que la télédétection active lidar est une méthode de mesure performante pour la caractérisation des forêts à partir d’observations aéroportées ; elle reste très attractive pour des systèmes spatiaux en orbite basse, entre 300 et 500 km, comme la station spatiale internationale. / The research presented in this thesis aims at evaluating the usage of active remote sensor lidar, from space platforms to monitor forest systems at a global scale. Forest is one of the main climate regulators through biogeochemical cycles, in which the most important processes are water cycle and carbon cycle. However, it is still poorly documented at a global scale because it is not always easy to get the information. Airborne and spaceborne observations, through remote sensing, are therefore the most suitable approaches to characterize the interactions between forest and atmosphere, at a regional or global scale. In order to improve the lidar remote sensing, it was necessary to build a representative database of different forest types, from managed forest to primary tropical forest. These data are obtained from several experiments using a new airborne demonstrator, the ULICE (Ultraviolet LIdar for Canopy Experiment). These data allows us to evaluate different uncertainty sources associated with the measurements for the extraction of corresponding forest parameters (i.e. tree height, aboveground biomass, leaf area index, etc.). This evaluation is based on the development of a numerical simulator which takes into account the surface characteristics, the atmosphere, the lidar instrumentation, and the satellite orbitography. We show that the active remote sensing sensor lidar is a powerful measuring method to characterize the forest from airborne observations; it remains very promising for spaceborne systems in low orbit, between 300 and 500 km, as the International Space Station.

Os sistemas de condicionamento de ar exercem função importante em uma sala cirúrgica, que é proteger a ferida cirúrgica e os equipamentos estéreis dos microrganismos carreados pelo ar. Essa proteção é feita pelo controle simultâneo da movimentação e distribuição do ar, da temperatura, da umidade, da filtragem, das infiltrações de ar de outros setores, entre outros. Esses são fatores que afetam diretamente a quantidade de partículas aéreas presentes em uma sala cirúrgica. Dentro deste contexto, no presente trabalho foi desenvolvido um modelo matemático para predição da concentração de partículas em salas cirúrgicas e para determinação da importância relativa dos fatores que interferem na geração e remoção dessas partículas. O modelo proposto baseia-se no balanço de massa para o cálculo da concentração de partículas, que foi aplicado e validado com os dados obtidos em salas cirúrgicas com diferentes tipos de sistemas de condicionamento de ar. Nessas salas cirúrgicas foram realizadas medições de variáveis ambientais considerando diferentes situações que normalmente ocorrem na rotina de salas cirúrgicas. Para cada uma das condições analisadas, é proposto um determinado conjunto de parâmetros relativos ao ambiente, ao sistema de condicionamento de ar e às concentrações de partículas provenientes das diversas fontes, que são utilizados como dados de entrada no modelo. O modelo que está sendo proposto também pode ser utilizado como uma importante ferramenta para auxiliar na análise específica dos fatores que afetam tanto a geração como a remoção de partículas. / Air conditioning systems exert an important function in surgical rooms, to protect the surgical wound and the sterile equipments from airborne infected particles. This protection is achieved by means of a simultaneous control of the movement and distribution of the air, of the temperature, of the humidity, of the filtering, of air infiltrations from other sections etc. Those factors directly affect the amount of airborne particles present in a surgical room. Within this context, the present work aimed to develop a mathematical model for the prediction of particle concentrations in surgical rooms and for the determination of the relative importance of the factors that interfere in the generation and removal of those particles. The proposed model, based on mass balance for the calculation of the particle concentrations, has been applied and validated with the data obtained from different types of air conditioning systems in which the measurements were carried out, as well as with different conditions that commonly occur in the routine of surgical rooms. For each one of these conditions, a certain group of relative parameters is proposed to the environment, to the air conditioning system, and to the concentrations of particles originated from the different sources, which are used as input data to the model. The proposed model can also be used as an important tool to aid in the specific analysis of the factors that affect both particle generation and removal.

As concentrações de urânio equivalente, tório equivalente, potássio e taxa de exposição foram determinadas em diferentes dias e horários para um mesmo local, a partir de dados gamaespectrométricos aerotransportados, medidos a uma altura média de 81 metros. Os perfis individuais foram então comparados com os perfis médios de todas as medidas. Os efeitos do radônio atmosférico e dos seus produtos de decaimento foram corrigidos com um pacote de cristais detectores extras voltados para cima, e os valores de calibração desses foram determinados a partir dos dados dos testes de radiação gama atmosférica: medidas acima de 760 metros de altura. A influência da radioatividade dos solos e rochas nos detectores voltados para cima foi corrigida de acordo com a técnica desenvolvida por Grasty e Hovgaard (1996) e discutida para as duas situações que elas são propostas. / The concentration of equivalent uranium, equivalent thorium, potassium and exposure rate were calculated on different days and hours for the same location, from airborne gamma ray spectrometric data, measured at an average height of 81 meters. The individual profiles were compared with mean profiles of all the measurements. The effects of atmospheric radon and its decay products were corrected using a pack of additional detectors crystals facing up (upward looking detector), and the calibration values these were determined from test data of atmospheric gamma radiation: measurements above 760 meters in height. The influence of radioactivity in soil and rocks in the upward looking detector was corrected according to the technique developed by Grasty and Hovgaard (1996) and discussed the two situations for which they are proposed.

O Maciço Alcalino máfico-ultramáfico Ponte Nova localiza-se no setor norte da Província Serra do Mar, junto à porção oriental da Serra da Mantiqueira, na fronteira dos Estados de São Paulo e Minas Gerais. Caracteriza-se por dois afloramentos de áreas 5 km² e 1 km². Dados magnéticos obtidos dos aerolevantamentos realizados para a CPRM pela Microsurvey Aerogeofísica e Consultoria Científica Ltda evidenciaram a presença de uma anomalia magnética extensa e de grande amplitude sobre os afloramentos. Este trabalho apresenta os resultados da interpretação geofísica e de modelagem direta integrando os dados aeromagnéticos com dados geológicos e gravimétricos do maciço visando uma caracterização do maciço em subsuperfície. Para uma determinação mais eficaz da localização e das dimensões da fonte da anomalia magnética, foram utilizadas técnicas de redução ao polo, amplitude do sinal analítico da anomalia magnética de campo total e aplicação de derivadas direcionais. Em laboratório, foram medidas as susceptibilidades magnéticas e intensidade da magnetização remanente natural de 14 amostras retiradas da região. Os resultados confirmaram a presença de magnetização remanescente em algumas das amostras, e susceptibilidade magnética média da ordem de 10-2 SI. A partir da conjunção dos dados do aerolevantamento e de dados geológicos, foi feita a modelagem direta 3-D com as propriedades magnéticas parametrizadas pelas medidas em laboratório. Os modelos consideraram a discriminação das fácies petrográficas do maciço, com susceptibilidades magnéticas variando de 0,1 a 0,9 SI. Os corpos modelados atingiram profundidades da base de pelo menos 3 km e seus volumes foram da ordem de 25 km³. Com base nas dimensões obtidas nos modelos magnéticos diretos, foi realizado um modelo gravimétrico direto com valores de densidade variando entre 2,77 g/cm³ e 3,30 g/cm³. Os resultados obtidos pelos modelos diretos foram discutidos e comparados com o modelo geológico e com outros modelos gravimétricos desenvolvidos. Apesar dos resultados alcançados pelos modelos apresentarem valores compatíveis com os observados nos levantamentos, os modelos não permitiram discriminar entre as duas hipóteses de trabalho sobre a configuração do maciço em subsuperfície: um corpo único que aflora em duas regiões ou dois corpos desconectados em subsuperfície. / The Ponte Nova mafic-ultramafic alkaline massif is located in the northern sector of the Serra do Mar Province, near the eastern portion of the Serra da Mantiqueira, on the border of the states of São Paulo and Minas Gerais. It is characterized by two outcrops measuring 5 km² and 1 km² of area. Magnetic data obtained from the airborn surveys carried out for the CPRM by Microsurvey Aerogeofísica and Consultoria Científica Ltda. evidenced the presence of an extensive magnetic anomaly with great amplitude on the outcrops. This work presents the results of geophysical interpretation and direct modeling integrating the aeromagnetic data with geological and gravimetric data of the massif, aiming a characterization of the massif in the subsurface. To determine a better location and shape values of the magnetic anomaly\'s source, we use pole reduction techniques, amplitude of the analytical signal of the total field magnetic anomaly and directional derivative applications. Magnetic susceptibilities and natural remanent magnetization intensity of 14 samples from the region were measured in laboratory. The results confirm the presence of remanent magnetization in some samples, and the average magnetic susceptibility about 10-2 SI. From the conjunction of the aero-survey data and the geological data, two direct 3-D model were developed with the magnetic properties parameterized by the laboratory measurements. These models considered different petrographic facies, with magnetic susceptibilities ranging from 0.1 to 0.9 SI. The modeled bodies reached depths of the base of at least 3 km and their volumes were about 25 km³. Based on the dimensions obtained from direct magnetic models, a direct gravimetric model was performed, with density values ranging from 2.77 g / cm³ and 3.30 g / cm³. The results obtained by the direct models were discussed and compared with the geological model and with other existing gravimetric models. Although the direct models yielded results compatible with those observed in the surveys, the results do not allow for discrimination of the following working hypotheses on the configuration of the subsurface massif: a single body outcropping in two regions or two bodies disconnected in the subsurface.