17 documents found, page 1 of 2

Introducing mapping standards in the quality assessment of buildings extracted ...

Many municipal activities require updated large-scale maps that include both topographic and thematic information. For this purpose, the efficient use of very high spatial resolution (VHR) satellite imagery suggests the development of approaches that enable a timely discrimination, counting and delineation of urban elements according to legal technical specifications and quality standards. Therefore, the nature...

The resource valuation and the challenge of coastal ecosystem-based management ...

Coastal risk evolution and changes in coastal systems: case study of north beac...

Avaliação Preliminar da Qualidade Posicional de uma Orto-Imagem QuickBird

Este trabalho foi realizado no âmbito do projecto GeoSAT, que teve como objectivo a definição de metodologias para extracção de informação geográfica a partir de imagens de satélite de alta resolução em ambiente urbano. Nesta comunicação apresentam-se e descrevem-se os processos de avaliação da qualidade posicional, de uma orto-imagem do satélite QuickBird da cidade de Lisboa, desde a recolha dos pontos até à a...

Producing a Building Change Map for Urban Management

The high rate of changes in cities requires the existence of matching geographic information in or-der to enable proper land monitoring and planning. When cartographic information exists, but is out-dated, a change detection procedure using recent geographic data can be applied for map up-dating. The aim of such an analysis is to highlight those areas where changes have most likely oc-curred. The goal of this w...

Preliminary Assessment of the Positional Accuracy of a Quickbird Ortho Image

This work has been accomplished on the scope of the GeoSAT research project, where the main goal was the definition of methodologies for geographic information extraction from high-resolution satellite images in an urban environment. This paper is intended to present and describe the positional quality assessment processes, of a QuickBird satellite ortho image from the city of Lisbon. For evaluate the possible ...

Hierarchical object-based classification of dense urban areas by integrating hi...

In Portugal, updating municipal plans (1:10 000) is required every ten years. High spatial resolution imagery has shown its potential for detailed urban land cover mapping at large scales. However, shadows are a major problem in those images and especially in the case of urban environments. The purpose of this study is to develop a less time consuming and less expensive alternative approach to the traditional g...

Producing a building change map for urban management purposes

The high rate of changes in cities requires the existence of matching geographic information in order to allow a proper land monitoring and planning. The work presented in this paper is the exploration of very-high resolution (VHR) imagery as an alternative source of geospatial information for large scale mapping to assist municipal urban planning in Portugal. The goal is to produce an alarm system that indicat...

Hierarchical object-based classification of dense urban areas by integrating hi...

In Portugal, updating municipal plans (1:10 000) is required every ten years. High spatial resolution imagery has shown its potential for detailed urban land cover mapping at large scales. However, shadows are a major problem in those images and especially in the case of urban environments. The purpose of this study is to develop a less time consuming and less expensive alternative approach to the traditional g...

Extracting buildings in the city of Lisbon using Quickbird images and lidar data

The methodology is based on semi-automatic extraction of features, using information from a QuickBird image and LIDAR data. The QuickBird image is suitable to delineate the different elements on the surface based on their spectral characteristics. However, this task is much more successful and richer when altimetric information is also used in the extraction process. Thus, with the introduction of LIDAR data, w...