Sensoriamento remoto como suporte para estudos cartográficos sobre o território da América Portuguesa entre 1500 e 1822

This article discusses the use of satellite imaging as a means to support and map out the historical expansion of the borders of São Paulo State between the discovery of Brazil and its independence. This tool was employed in Cartography of a history, an exhibition staged at Museu Paulista/USP in 2005. The images were generated by Modis, Shuttle Radar Topographic Mission and Landsat-5, and georeferenced with the SPRING image processor as well as georectified mosaics made available by Nasa. They were then checked against a valuable set of cartographic data collected by the researchers working under the Jaime Cortesão History Chair at USP. The said set included information pertaining to the boundaries established by the Treaty of Tordesillas, with its distortions; the Map of the Courts; the captaincies; as well as the trails of bandeiras (exploring expeditions), monções (expeditions made up and down the rivers of the São Paulo and Minas Gerais captaincies), and tropeirismos (cattle driving routes). In other words, all the pioneering actions that helped to consolidate the territory of São Paulo State and to shape much of Brazil's spatial identity were traced in the images. The researchers also looked into the myth of Brazil as an island and into the purported connection between the Amazon and Paraná-Prata river basins based on their geomorphologic attributes as shown on the orbital images. The results were compiled into an 800-megabyte database and displayed at Museu Paulista. This paper describes the methodological procedures used to generate and analyze the images, and provides a summary of the research findings.Este artigo aborda a utilização de imagens de satélites como suporte para evidenciar a expansão histórico-cartográfica das fronteiras paulistas entre o descobrimento do Brasil e a sua independência, recurso esse utilizado na exposição Cartografia de uma história, realizada no Museu Paulista da USP em 2005. As imagens foram aquelas do Modis, do Shuttle Radar Topographic Mission e do Satélite Landsat-5. As cenas foram georreferenciadas valendo-se da ferramenta Spring e dos mosaicos georretificados disponibilizados pela Nasa. Sobre estes produtos foi lançado um valioso conjunto de informações cartográficas coletadas pelas pesquisadoras da Cátedra Jaime Cortesão da USP. O conjunto inclui o Tratado de Tordesilhas, com suas distorções, o Mapa das Cortes, as capitanias, as bandeiras, as monções, as trilhas, os tropeirismos, ou seja, todo o conjunto de ações pioneiras que permitiram consolidar o território paulista e grande parte da identidade espacial brasileira. Foram analisados também o mito da Ilha Brasil e os enlaces das bacias do rio Amazonas e do rio Paraná-Prata a partir dos atributos geomorfológicos dispostos nas imagens orbitais. Os resultados foram consolidados em um banco de dados de 800 megabites, sendo dispostos em exposição junto ao Museu Paulista. Este artigo descreve os procedimentos metodológicos de geração e de análise das imagens bem como sintetiza os resultados alcançados

Distribution of the daily Sunspot Number variation for the last 14 solar cycles

The difference between consecutive daily Sunspot Numbers was analysed. Its distribution was approximated on a large time scale with an exponential law. In order to verify this approximation a Maximum Entropy distribution was generated by a modified version of the Simulated Annealing algorithm. The exponential approximation holds for the generated distribution too. The exponential law is characteristic for time scales covering whole cycles and it is mostly a characteristic of the Sunspot Number fluctuations and not of its average variation.Comment: Accepted for publication in Solar Physic