Armazenamento e Recuperação de Dados Matriciais em Bancos de Dados Objeto-Relacionais

Esse trabalho examina algumas quetões relatives a construção de bases de dados geográficos, mais especificamente daqueles representados em uma estrutura matricial. Uma arquitetura geral é apresentada. Essa arquitetura baseia-se na combinação de dois mecanismos: particionamento e multi-resolução. Apresenta-se alguns algoritmos desenvolvidos para implementar tais mecanismos. Apresenta-se ainda exemplos de implementação desse modelo em dois SGBDs objeto-relacionais: MySQL e PostgreSQL. Para esse exemplo são discutidas algumas questões de eficiência na recuperação desses dados

Explorando a extensão WKT Raster do PostGIS para armazenamento e manipulação de imagens de sensoriamento remoto

Spatial extensions allow DMBS systems to story and query spatial data using high-level query languages capable of expressing complex queries mixing descriptive and spatial criteria. This works explores the WKT Raster, part of PostGIS, the spatial extension for PostgreSQL, to manage raster data, more specifically remote sensing imagery. This spatial extension was chosen, because it is, to the authors knowledge, the most mature product that is free of license. Some typical remote sensing operations are executed using only the query language available in the WKT Raster. The results show that WKT Raster is a promising tool to handle raster data in object-relational databases. Some interesting features are the integration to the spatial types used to handle vector data and the large number of processing operators.Pages: 4700-470

Construção de um plug-in TerraView para extração de geotags de fotos digitais

Geosciences studies frequently require to conduct field works. When a huge amount information is collected during such surveys, its manipulation, organization and interpretation is, generally, an arduous task. A tool resulting from advances in Geotechnology are GPS cameras. They are capable to record the geographical position of the locations photographed, which are extremely useful when performing field surveys. The present work had aimed to build a plug-in for GIS TerraView able to use information captured by GPS cameras to generate spatial databases, making manipulation, organization and visualization of collected data easy and fast.Pages: 8912-891

Image data handling in spatial databases

The recent advances in database technology have enabled the development of a new generation of spatial databases, where the DBMS is able to manage spatial and non-spatial data types together. Most spatial databases can deal with vector geometries (e.g., polygons, lines and points), but have limited facilities for handling image data. However, the widespread availability of high-resolution remote sensing images has improved considerably the application of images to environmental monitoring and urban management. Therefore, it is increasingly important to build databases capable of dealing with images together with other spatial and non-spatial data types. With this motivation, this paper describes a solution for efficient handling of large image data sets in a standard object-relational database management system. By means of adequate indexing, compression and retrieval techniques, satisfactory performances can be achieved using a standard DBMS, even for very large satellite images. This work is part of the development of the TerraLib library, which aims to provide a comprehensive environment for the development of GIS applications