Imagens Do Satélite Spot-1 Em Mapeamento Geológico: Um Estudo Comparativo Com Vários Produtos Sensores No Vale Do Rio Cüraçá, Bahia
Year: 1990
Type: article
Abstract: CURAÇÁ RIVER VALLEY, BAHIA.The advent of new remote sensing products from TM-LANDSAT and SPOT with geologically interesting technical characteristics but higher acquisition prices compared to the MSS, brought up the need of performance evaluation in the Brazilian territory.The goal of the present work is to qualitatively compare the spatial and spectral performances of multispectral and panchromatic SPOT under oblique viewing with TM and MSS-LANDS AT and air photos in the context of structural and lithological mapping.The test area with nearly 900 km 2 is located in the lower Valley of Curaçá River, Northeast of Brazil (State of Bahia) and is characterized by precambrian terrains in a semiarid environment.Photographic paper products were submitted to visual analysis-to appropriate scales for regional and local mapping, and digital data were subjected to enhancement 'and merging processing.Additionaly, digital data were normalized into radiometric values with the purpose of detecting oblique viewing effects.Radiometric values from west pointing SPOT and nadir TM from the same sites have shown differences that can be attributed to the greater atmospheric interference in the SPOT viewing configuration.Such difference is greatest at the shorter wavelengths and decreases towards the near infrared, but without serious degradation in the context of the present study.At the reginal scale, neither SPOT nor TM-LANDSAT, in photographic paper products, have added significant geological information to the previous map based on computer processed MSS-LANDSAT data.However, computer merged products have shown that lithological discrimination can be enhanced by the combination of the high spatial resolution SPOT panchromatic image with the geologically important infrared TM bands.Similarly, the stereo vision provided by SPOT pairs can be combined with processed TM products to optimize interpretation at local scales.Whereas the latter requires expensive digital processing, the stereoscopic vision need a pair of opposing oblique viewing obtained under clear atmospheric conditions and a special schedule in the satellite coverage, which represent additional difficulties in the acquisition of SPOT stereo data.
Institution: Instituto Nacional de Pesquisas Espaciais
Language: Portuguese
Subfield: Computer Vision and Pattern Recognition
Field: Computer Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W4246639375