Análise comparativa de imagens Sentinel-2A (MSI) e Landsat-8 (OLI) aplicadas ao mapeamento geológico, Região de Itataia, Santa Quitéria, CE

Abstract

Satellites equipped with multispectral sensors, such as the Landsat (TM, ETM +, OLI) series, play an important role in geological applications, especially sensors that have spectral bands in short-wave infrared, because it is in this region of the spectrum that mineral groups such as that of the clays, present peaks of reflectance. The satellite of the mission Sentinel-2, from Copernicus program of European Spatial Agency-ESA have the intended to provide continuity to missions like Landsat and SPOT. The phosphorus-uraniferous province of the Itataia, object of this study, is located in the municipality of Santa Quitéria (CE) and inserted in the geological context of the Domínio Ceará Central (DCC) of Província Borborema (PB).The aim of this paper is to accomplish the comparation of imagens from MSI Sentinel-2 and OLI Landsat-8 sensors, by means of statistical parameters, as the Pearson coefficient, and analyze your applications for geologial mapping. For that, the correlated bands of both sensors were selected, preprocessed for a compatible set of data for comparison. Subsequently, the coefficients were generated between the pairs of correlated bands, as well as band ratios for data analysis. The Sentinel-2 images, analyzed in this work, presented a strong correlation with the images of Landsat-8, with Pearson coefficients varying between 0.857 and 0.935, and the band ratios presented a coefficient varying between 0.772 and 0.910. The highest correlations were between short-wave infrared (SWIR) bands, with Pearson coefficients of 0.935 between bands 6 (OLI) and 11 (MSI), 0.926 for bands 7 (OLI) and 12 (MSI) and ratio with the highest coefficient was 6/7 (OLI) and 11/12 (MSI).This strong correlation between SWIR bands demonstrates the potential of Sentinel-2 images for geology work, since many mineral groups have peaks of reflectance in this spectral range.