Navegando por Assunto "Altimetria"

Agora exibindo 1 - 2 de 2

Acesso aberto (Open Access)
Aplicabilidade altimétrica no mapeamento fitogeográfico e uso da terra: contribuições ao planejamento territorial e à restauração ambiental
(Universidade Federal do Pará, 2019-03-13) SANTOS, Eduardo da Silva; BARBOSA, Wagner Luiz Ramos; http://lattes.cnpq.br/1372405563294070; SILVA, Christian Nunes da; http://lattes.cnpq.br/4284396736118279
This study aims to improve the mapping method for the vegetation cover, elaborated in the 1: 250,000 scale, using the theoretical reference of Classificação da Vegetação Brasileira Adaptada a um Sistema Universal by Veloso, Rangel-Filho and Lima (1991) ). The mapping of the vegetation units was carried out in corresponding to the forest formations and sub-formations of the IBGE vegetation. In this sense, the proposal of this research will enable, through a geotechnology tool, to rectify such designs. Starting from the official mapping (IBGE), later, it was superimposed on the hypsometric map generated in this work. As a result of this process, a new mapping of the vegetation cover properly adjusted to the classification used was obtained. In the assessment of the proposed mapping, a field validation was performed, having as its main axis the positional accuracy of the outlines of forest formations and sub- formations in the area under study. The research was carried out in the Municipality of Paragominas, State of Pará, with a total area of 19,342,254 km2. The results showed a strong need for inclusion of this device in the methodological process, since deep changes in the spatialization of these designs (forest formations and sub - formations) were performed and rectified, both in the qualitative and/or quantitative aspects, which are observed in the comparative map between the official data and the proposed data: Official Map Db 43%, in the Proposed Map, it changed to 52.95%; In the Official Map Ds 54.98%, in the Proposed Map, it was 45.68%. The analysis of the environmental liability was carried out in the SICAR database available in November/2018, corresponding to 93.4% of registered properties, presenting the following 85.15% of the Legal Reserves have anthropogenic levels in the range of <40; that is, low anthropization; 8.95% of the RL (s) are in the range of> 60, that is, high anthropization; and 5.9% of the RL (s), are in the range of 40-60, that is, average anthropization. In this way, the final product meets a more effective instrument and, in a way, can be best used in territorial planning actions.
Acesso aberto (Open Access)
Avaliação de dados de altimetria do satélite Geosat a partir de comparação com dados do levantamento gravimétrico marinho Equant
(Universidade Federal do Pará, 1992-02-26) MARQUES, Maria do Socorro Pereira; O'BRIEN, Douglas Patrick
The principal objective of this thesis is to evaluate the use of satellite altimetry data to map the potential surface of the earth's gravity field at sea. This evaluation is done by comparing the resolution and accuracy of the altimeter data over an equipotential surface (the sea) with that computed from conventional sea survey data. From the potential surface, quantities such as the free air anomaly or the vertical deflection can be calculated. The altimetry data utilized in this thesis were collected by the Geosat satellite and each data point was averaged over a two year (44 orbital cycles) period. This averaging was done to improve the accuracy and resolution of the sea height over ocean areas. These data are available from NOAA and were supplied to UFPa for use in this thesis. The ship survey data from EQUANT 1 and EQUANT 2 were generated from a joint research project among several institutions whose scientific objective was to study the behavior of the Brazilian Equatorial Continental Margin. In order to integrate and compare the data between these two different sources (satellite and ship measurements), either the satellite data must be reduced to a vertical acceleration on the equipotential surface or alternately the ship survey data must be transformed into an equivalent potential surface. Taking into account the wide separation of the satellite tracks relative to the ship survey track, it was decided to transform the ship survey data into a potential surface, and the correlation and comparisons were carried out along satellite tracks. In this type of transformation, various factors must be considered such as the effects of aliasing, ship survey noise levels, reduction to the geoid, computational errors in the transformation, etc. In spite of these effects (particularly the aliasing problem) the results reflect a strong correlation between the two sets of data verifying that a satisfactory level of coherence exists for wavelengths greater than 11 km. The resolution for the 2 year cycle average of the satellite is, in fact, almost as good as the ship survey data.