• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 8
  • 8
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Statistical methods on automatic aircraft recognition in aerial images

Wei, Yi January 2002 (has links)
No description available.
2

Informal Development in Cairo, the View from Above: A Case Study Using Aerial Photo Interpretation to Examine Informal Housing in the Imbaba District of Cairo

Bullard, Stevan 09 June 2006 (has links)
The goal of this study is to apply the extraordinarily rich set of historical cartographic and remote sensing data of Cairo, Egypt to the analysis of the problem of informal development in the twentieth century. Remote sensing of urban areas has been dominated in recent years by multispectral analysis of Landsat imagery. This restricts studies both temporally and in spatial resolution. In this study an aerial photo interpretation methodology is applied to images and maps spanning two centuries of Cairo’s history at a spatial resolution on the scale of individual buildings. From these techniques insights can be obtained of the political and social forces shaping the development of Cairo.
3

Alla barn är lika mycket värda : En kvalitativ studie om hur barn framställs i KappAhls reklamfilmer / All children are equally worth : A qualitative analysis of how children are produced in KappAhls commercials

Lindqvist, Hanna January 2015 (has links)
I have written an essay called ”All children are equally worth - A qualitative analysis of how children are produced in KappAhls commercials”. The purpose of this thesis is to do a study of the swedish clothing company KappAhl’s commercials. My purpose is divided into three questions: With which clothing colours are girls and boys represented in the commercials? Is there any difference in the making of ”non-white” and ”white” children in the commercials? and What is being transmitted in KappAhl’s commercials, where the focus should lay on the clothes? My material consists of three selected video clips from KappAhl’s Youtube channel. The three commercials are named: 1, Back to school, 2, Children’s christmas and 3, KappAhl 3 för 2 på alla överdelar för barn (translation: KappAhl 3 for 2 on all children’s tops). I have chosen to use photo interpretation with denotation and connotation as the main tools and also qualitative analysis as methods in my review of the material. The main theoretical base in my thesis is gender theory, while, for instance, stereotypes, binary oppositions and ethnicity are concepts chosen in hope to reach a deeper analytical level. I have also analyzed these commercials through the colours on the children’s clothes, the way the children are dressed and the settings around them. Through the analysis I have come to the conclusion that the children are dressed quite alike, in similar colors. But the girls are often dressed in colors that we find ”neutral” on girls, but if the boys would wear the colors that we find "neutral" on girls, we would see them as boyish. The boys would never wear colours that would seem ”neutral” on them, but in the general eye of society these colours would be seen as girl colors. The biggest difference I found in the commercials between ”non-white” and ”white” was that the ”white” younger boys were mystified through hats and hooded sweatshirts, and the ”non-white” boy, and the ”non-white” grown-up men were all themself with no assecceories trying to mystify them.
4

Cartographier l'occupation du sol à grande échelle : optimisation de la photo-interprétation par segmentation d'image. / Land cover mapping at large scale using photo-interpretation : Contribution of image segmentation

Vitter, Maxime 23 March 2018 (has links)
Depuis une quinzaine d’années, l’émergence des données de télédétection à Très Haute Résolution Spatiale (THRS) et la démocratisation des Systèmes d’Information Géographique (SIG) aident à répondre aux nouveaux besoins croissants d’informations spatialisées. Le développement de nouvelles méthodes de cartographie offre une opportunité pour comprendre et anticiper les mutations des surfaces terrestres aux grandes échelles, jusqu’ici mal connues. En France, l’emploi de bases de données spatialisées sur l’occupation du sol à grande échelle (BD Ocsol GE) est devenu incontournable dans les opérations courantes de planification et de suivi des territoires. Pourtant, l’acquisition de ce type de bases de données spatialisées est encore un besoin difficile à satisfaire car les demandes portent sur des productions cartographiques sur-mesure, adaptées aux problématiques locales des territoires. Face à cette demande croissante, les prestataires réguliers de ce type de données cherchent à optimiser les procédés de fabrication avec des techniques récentes de traitements d’image. Cependant, la Photo-Interprétation Assistée par Ordinateur (PIAO) reste la méthode privilégiée des prestataires. En raison de sa grande souplesse, elle répond toujours au besoin de cartographie aux grandes échelles, malgré son coût important. La substitution de la PIAO par des méthodes de production entièrement automatisées est rarement envisagée. Toutefois, les développements récents en matière de segmentation d’images peuvent contribuer à l’optimisation de la pratique de la photo-interprétation. Cette thèse présente ainsi une série d’outils (ou modules) qui participent à l’élaboration d’une assistance à la digitalisation pour l’exercice de photo-interprétation d’une BD Ocsol GE. L’assistance se traduit par la réalisation d’un prédécoupage du paysage à partir d’une segmentation menée sur une image THRS. L’originalité des outils présentés est leur intégration dans un contexte de production fortement contraint. La construction des modules est conduite à travers trois prestations cartographiques à grande échelle commandités par des entités publiques. L’apport de ces outils d’automatisation est analysé à travers une analyse comparative entre deux procédures de cartographie : l’une basée sur une démarche de photo-interprétation entièrement manuelle et la seconde basée sur une photo-interprétation assistée en amont par une segmentation numérique. Les gains de productivité apportés par la segmentation sont, évalués à l’aide d’indices quantitatifs et qualitatifs, sur des configurations paysagères différentes. À des degrés divers, il apparaît que quelque soit le type de paysage cartographié, les gains liés à la cartographie assistée sont substantiels. Ces gains sont discutés, à la fois, d’un point de vue technique et d’un point de vue thématique dans une perspective commerciale. / Over the last fifteen years, the emergence of remote sensing data at Very High Spatial Resolution (VHRS) and the democratization of Geographic Information Systems (GIS) have helped to meet the new and growing needs for spatial information. The development of new mapping methods offers an opportunity to understand and anticipate land cover change at large scales, still poorly known. In France, spatial databases about land cover and land use at large scale have become an essential part of current planning and monitoring of territories. However, the acquisition of this type of database is still a difficult need to satisfy because the demands concern tailor-made cartographic productions, adapted to the local problems of the territories. Faced with this growing demand, regular service providers of this type of data seek to optimize manufacturing processes with recent image-processing techniques. However, photo interpretation remains the favoured method of providers. Due to its great flexibility, it still meets the need for mapping at large scale, despite its high cost. Using fully automated production methods to substitute for photo interpretation is rarely considered. Nevertheless, recent developments in image segmentation can contribute to the optimization of photo-interpretation practice. This thesis presents a series of tools that participate in the development of digitalization assistance for the photo-interpretation exercise. The assistance results in the realization of a pre-cutting of the landscape from a segmentation carried out on a VHRS image. Tools development is carried out through three large-scale cartographic services, each with different production instructions, and commissioned by public entities. The contribution of these automation tools is analysed through a comparative analysis between two mapping procedures: manual photo interpretation versus digitally assisted segmentation. The productivity gains brought by segmentation are evaluated using quantitative and qualitative indices on different landscape configurations. To varying degrees, it appears that whatever type of landscape is mapped, the gains associated with assisted mapping are substantial. These gains are discussed both technically and thematically from a commercial perspective.
5

CARACTERIZAÇÃO DE ALVOS COM IMAGENS DO SENSOR MULTIESPECTRAL AEROTRANSPORTADO EPS-A 31T APOIADO POR DADOS DE ESPECTRORADIOMETRIA. / CHARACTERIZATION OF OBJECTIVES WITH IMAGES OF MULTISPECTRAL AIRBORNE SENSOR EPS-A 31T SUPPORTED BY SPECTRORADIOMETRY DATA.

Zanini, Adenilson Farias 01 December 2008 (has links)
The necessity to identify objects in the ground constituted by several types of materials became a challenge to the remote sensing researchers. This situation promoted new researches about sensors development and stimulated the improvement and the creation of new techniques and tools that assist in characterization of the targets. Following this necessity this research was developed with the objective of characterize urban targets in multispectral images, by means multivariated statistical analysis and supported by ground spectroradiometry. It was used the sensor MSS EPS A 31T, the spectroradiometer FieldSpec Pro FR and the softwares R 2.7 and ERDAS 8.7. It was realized a sensing in a continuous strip over the Federal University of Santa Maria RS in three distinct schedules, at 12:00 pm HBV and 04:00 pm HBV in 17/12/2008 and at 09:00 am HBV in 27/12/2007. The MSS sensor was operated from the R-99B, a FAB aircraft, on 31 channels mode, in the spectral interval of 0,42μm and 12,5μm and space resolution of 2,5m. parallel to the flight it was realized the reading of the radiation reflected by the targets on ground using the spectroradiometer, which operate in the continuous interval from 0,35 μm to 2,5 μm. A methodology allied with the photo interpretation is the analytic statistic, therefore with the technological evolution it became to associate the panchromatic aerial photographic with multispectrals images. The data obtained in the research were recorded and treated in their respective interfaces and converted to mains. The MSS 3 digital values were rejected from the research because of treatment incompatibility. Initially it was made the analysis of the main components, identifying the three main components (MSS sensor channels 7, 3 and 30), answering them for 99,947% and 99,948% of the originals variables variability to MSS 1 and MSS 2 respectively. From that was generated a high contrast image among the constituent materials of the proposed targets. The wavelength intervals of the three main components were retaken to mains structuring to the execution of the regression analysis. The main components were linked with the ground spectroradiometry realized readings, in their respective spectral intervals. The regression coefficients found had answered respectively for 76,99% of the MSS1 depended variables variability and 85,40% of the MSS 2. These percentages had expressed a better adjust in the second regression and in a smaller variability of the residual errors. The residual error s median to MSS 1 was - 0,2869 and to MSS 2 was 0,0851. The model validity verification was executed with the application of the variance analysis (ANOVA) that showed in F test the values: MSS 1= 66,91 e MSS 2 = 116,99. As the values of Ftab (F 5%;3;60) is equal 2,76, it is noticed that the values of Fcalc is bigger than Ftab , (Fcalc > Ftab), to both analysis. Through the obtained results it is concluded that the employed methodology is valid to characterize the proposed targets and the model contribute to distinguish among them in the MSS image analysis. / A necessidade de identificar objetos no solo constituídos por diversificados tipos de materiais tornou-se um desafio aos pesquisadores na atividade de sensoriamento remoto. Esta situação alavancou novas pesquisas na área de desenvolvimento de sensores e estimulou o aprimoramento e criação de novas técnicas e ferramentas que auxiliem na caracterização dos alvos. Acompanhando esta necessidade foi desenvolvida esta pesquisa, com o objetivo de caracterizar alvos urbanos em imagens multiespectrais, por meio de estatística multivariada, apoiado em espectroradiometria de solo. Foi utilizado o Sensor MSS EPS-A 31T, o espectroradiômetro FieldSpec Pro FR e os softwares R 2.7© e ERDAS 8.7®. Foi realizado o sensoriamento em uma faixa contínua sobre a Universidade Federal de Santa Maria-RS em três horários distintos, as 12:00HBV (MSS1) e 16:00HBV (MSS2) do dia 17/12/2007 e as 09:00HBV (MSS3) do dia 27/12/2007. O sensor MSS foi operado na aeronave R-99B, no modo 31 canais no intervalo espectral entre 0,42μm a 12,5μm, com uma resolução espacial de 2,5m. Paralelo ao vôo foi efetuado a leitura da radiação refletida pelos alvos no solo com o espectroradiômetro que opera na faixa de 0,35μm a 2,5μm. Uma metodologia que se alia a fotointerpretação é a da estatística analítica, pois com a evolução tecnológica passou-se a associar fotografias aéreas pancromáticas e imagens multiespectrais. Os dados gerados na pesquisa foram transferidos e convertidos em matrizes de dados. Os valores digitais de MSS3 foram descartados do trabalho por incompatibilidade no tratamento. Inicialmente foi executada a análise de componentes principais identificando-se as três principais componentes (canais 7, 3 e 30 do sensor MSS), respondendo estas por 99,947% e 99,948% da variabilidade das variáveis originais para MSS1 e MSS2, respectivamente. A partir desta gerou-se uma imagem de alto contraste entre os materiais constituintes dos alvos propostos. Os intervalos de comprimento de onda da análise de componentes principais foram retomados para a estruturação de matrizes que permitissem uma análise de regressão. As principais componentes foram, então, relacionadas com as leituras efetuadas na espectroradiometria de solo, em seus referidos intervalos espectrais. Os coeficientes de regressão encontrados responderam respectivamente por 76,99% da variação da variável dependente em MSS1 e por 85,40% em MSS2. Estes percentuais traduziram-se em um melhor ajuste na segunda regressão e uma menor variabilidade dos erros residuais. A média dos erros residuais para MSS1 foi -0,2869, enquanto que em MSS2 foi -0,0851. A verificação da validade do modelo foi efetuada com a aplicação da análise de variância (ANOVA) que retratou no teste F os valores: MSS1= 66,91 e MSS2= 116,99. Como o valor do Ftab (F 5%;3;60) é igual a 2,76, percebe-se que o valor de Fcalc é maior que o valor do Ftab , (Fcalc > Ftab) para as duas análises. Pelos resultados alcançados conclui-se que a metodologia empregada é valida para a caracterização dos alvos propostos e o modelo contribui para a distinção entre estes na análise de imagens MSS.
6

Forest edges in boreal landscapes - factors affecting edge influence

Jansson, Ulrika January 2009 (has links)
The boreal forest in Fennoscandia has been subjected to major loss and fragmentation of natural forests due to intensive forestry. This has resulted in that forest edges are now abundant and important landscape features. Edges have documented effects on the structure, function and biodiversity in forests. Edge influence on biodiversity is complex and depends on interactions between many local and regional factors. This thesis focuses on sharp forest edges and their potential to influence biodiversity at the landscape-level. I have developed a method for quantification and characterization of sharp forest edges by interpretation of colour infrared (CIR) aerial photographs in combination with line intersect sampling (LIS) and sample plots. The method was used to estimate density of forest edge in 28 landscapes (each 1600 ha) in northern Sweden, differing in management intensity, landscape composition and geographical location. Forest edges were described in detail using edge, canopy and neighbourhood attributes. By combining these attributes it was possible to classify edges with respect to levels of exposure. A field experiment was conducted to examine the effect of edge contrast on growth of the old forest lichen Usnea longissima. The edge quantification method is accurate and efficient for estimating the length of sharp forest edges on an area basis (edge density, m ha-1) and for collecting detailed attributes of edges and their surroundings. In northern Sweden, the forest edge density is high (54 m ha-1) but varies extensively (12-102 m ha-1) between landscapes. Edge density is strongly correlated with the level of human disturbance and increases towards the southern part of the study area, at lower altitudes were management intensity is highest. Edge orientation, contrast and neighbourhood size shows an immense variation between edges and also varies between edge types. Regenerating edges are generally of higher contrast and face larger neighbourhoods than natural edges. Maintained edges had high contrast but small neighbourhoods. A larger proportion of edges in mature forests are highly exposed to microclimatic edge influence than edges in general. The field experiment revealed that growth of U. longissima was highest near edges where the vegetation on the adjacent area was sheltering, but not shading, the lichen. In the present thesis, I have provided a valuable tool for estimating density of forest edges with potential to yield information on important factors determining edge influence at landscape-level. The large variability in edge density, edge and neighbourhood attributes imply large differences in microclimate anf thus in the potential for ede influence. Management and conservation strategies must incorporate these factors to realistically address edge influence on biota at the landscape-level.
7

Utveckling av biotopdatabas och tillämpning av landskapsekologisk analys i Huddinge kommun

Bovin, Mattias January 2014 (has links)
På grund av ökad urbanisering och exploatering av grönområden i stadsnära miljöer fragmenteras och reduceras arters habitat vilket bland annat ligger till grund för den globalt minskade biologiska mångfalden. För att stärka och förbättra arters möjlighet till spridning i landskapet, och därmed säkra en hög biologisk mångfald, efterfrågas insamling av data och utveckling av nya metoder för att identifiera ekologiska kärnområden och för att analysera habitatnätverk. Syftet med den här studien är därför att 1) kartera och sammanställa biotoper i en biotopdatabas utifrån tolkning av infraröda flygbilder med digital stereofotogrammetri, 2) undersöka olika metoder att samla in data med hjälp av laser- och höjddata, och 3) att tillämpa landskapsekologisk analys på underlag i biotopkarteringen. Resultatet validerar att tolkning av infraröda flygbilder med digital stereofotogrammetri är en utmärkt källa för att kartera biotoper som medför en tolkningsnoggrannhet på 86 %. Valideringen av kateringen genomfördes med fältkontroller som utvärderades i felmatriser. En metod har även undersökts baserat på tidigare studier för att uppskatta busk- och krontäckning med hjälp av laserdata, men eftersom det saknas validering av resultatet bör den användas som en indikator för att visuellt uppskatta busk- och krontäckning i dagsläget. Fortsättningsvis har ett topografiskt fuktighetsindex (TWI) tillämpats med hjälp av höjddata för att uppskatta fuktighet i vegetationstäckta områden. Eftersom det saknas validering och tröskelvärden för att avgöra hur TWI ska klassificera olika fuktighetsgradienter, bör verktyget endast användas som en indikator för att visuellt uppskatta fuktighet tillsammans med tolkning av infraröda flygbilder. Om metoderna valideras med fältmätningar kan de bidra med att förbättra kvaliteten och tidseffektivisera kartering av biotoper. Biotopkarteringen fungerar som ett bra underlag vid tillämpning av landskapsekologisk analys. Med hjälp av MatrixGreen var det möjligt att modellera potentiella habitatnätverk för två olika arter inom studieområdet. På grund av en del problem med modelleringen i MatrixGreen bör resultaten beaktas med ett kritiskt angreppssätt, men kan eventuellt användas som ett underlag för framtida artinventeringar. / Due to urbanisation and exploitation of green areas in cities during the last decades, the rate of habitat fragmentation has increased, resulting in a decline in the global biodiversity. In order to strengthen the possibilities of species migration, and to secure a high biodiversity, there is an increasing demand in the collection of data and in the exploration of methods to identify ecological core areas and to analyse habitat networks at a landscape level. Therefore, this study aims to 1) map and organise biotopes in a biotope database using interpretation of colour infrared aerial photos in digital stereophotogrammetry, 2) to explore different methods using laser and elevation data in order to improve the collection of ecologically important attributes, and 3) to apply landscape ecological analysis on the collected biotope data. The results validate interpretation of colour infrared aerial photos with digital stereophotogrammetry as a key source in mapping biotopes with an overall accuracy of 86 %. A method to estimate bush and crown cover has been explored based on previous studies using laser data. It has however not been validated in this study and should therefore be used as an indicator and as support for visual estimation of bush and crown coverage using CIR aerial photo interpretation. Furthermore, a topographic wetness index (TWI) was applied using elevation data in order to estimate moisture regimes in vegetated areas. It should also be used as an indicator due to lack of verification and limitations of arranging TWI values in relation to different moisture regimes. However, if these two methods are validated using field collected data for example, they hold significant potential in improving mapping accuracies and mapping rates of different biotopes. Collected biotope data are well suited in the application of landscape ecological analysis. Using MatrixGreen, it was possible to analyse potential habitat networks of two different species within the study area. Due to some problems in the least cost path modeling in MatrixGreen, the results should be carefully assessed, but could probably be used as a background material for future species inventories.
8

Geografia de la brisa marina a Mallorca

Alomar Garau, Gabriel 12 July 2012 (has links)
El fenomen atmosf��ric de les brises marines adopta a l���illa de Mallorca caracter��stiques protot��piques, i la seva efectivitat permet una f��cil constataci�� com�� i la subseq��ent verificaci�� cient��fica. Operant simult��niament des de les diferents costes, les brises adquireixen un car��cter unitari i centr��pet que ocasiona converg��ncies d���aire a ��rees de l���interior, a on la precipitaci�� estival tendeix a focalitzar-se. L���espai agrari de Mallorca s���ha conformat hist��ricament amb el massiu desplegament territorial d���infrastructures de base cereal��stica, fonamentalment eres de batre. El principal factor de la seva localitzaci�� ��s la disponibilitat de vent, tot constituint unitats de significaci�� e��lica susceptibles d���interpretar-se en clau clim��tica. La seva georeferenciaci�� per fotointerpretaci�� de l���ortofotografia de l���any 1956 s���ha tradu��t en un mapa sint��tic d���eres, m��s una metodologia in��dita per a determinar indirectament les direccions del vent a cada empla��ament. El model ���anemogr��fic��� resultant s���ajusta amb relativa bondat amb les simulacions del sistema de brises precedents. / El fen��meno atmosf��rico de las brisas marinas adopta en la isla de Mallorca caracter��sticas protot��picas, y su efectividad permite una f��cil constataci��n com��n y la subsiguiente verificaci��n cient��fica. Operando simultaneamente desde las diferentes costas, las brisas adquieren un car��cter centr��peto que ocasiona convergencias de aire en ��reas del interior, donde la precipitaci��n estival tiende a focalizarse. El espacio agrario de Mallorca se ha conformado hist��ricamente con el masivo despliegue territorial de infraestructuras de base cereal��stica, fundamentalmente eras de trillar. El principal factor de su localizaci��n es la disponibilidad de viento, constituyendo unidades de significaci��n e��lica susceptibles de interpretarse en clave clim��tica. Su georeferenciaci��n por fotointerpretaci��n de la ortofotografia del a��o 1956 se traduce en un mapa sint��tico de eras, m��s una metodolog��a in��dita para determinar indirectamente las direcciones del viento en cada emplazamiento. El modelo ���anemogr��fico��� resultante se ajusta con relativa bondad con las simulaciones del sistema de brisas precedentes. / In Mallorca, sea breeze presents prototypical characteristics. It is so consistent that its effectiveness allows for easy common as well as scientifc verification. Daytime breezes operate simultaneously from different coasts, and penetrate inland. Its centripetal nature causes wind convergences in certain inland areas, where summer rainfall tend to focus. The agricultural area has historically made with massive territorial deployment of cereal production infrastructure, mainly threshing floors, the main factor of its location being the quantity of the wind resources available. These are small circular spaces that can be interpreted in relation to climate. A synthetic chart of threshing floors and a methodology designed to indirectly determine the dominant wind directions at each site have been developed, based on their geo-referencing by photo-interpretation of the ortho-photographs of 1956. The resulting ���anemographic��� model fits nicely with the main features of the sea breezes identifed by the theoretical-experimental and numerical simulations already tested.

Page generated in 0.1429 seconds