Sentinel-2A Images and Spectroradiometry Applied to Degraded Grassland Study

Abstract

The goal of this study is distinguish on remote sensing data, different conservation stage from pasture areas, using laboratorial analysis, orbital images and field spectroscopy, comparing field and laboratory methods. Was studied two pasture areas with grass Brachiaria decumbens, the area 1 without degradation and the area 2 degraded. The orbital sensor changed chosen was Sentinel-2 MSI, and yours images was used on Leaf Area Index (LAI) estimative and in obtaining the reflectance of the canopies, as well as using a field spectrometer. The concentration of chlorophyll was quantified, where the degraded area presented lower values, denoting low force. The LAI computation was efficient in the separation of the degraded area, which presented lower LAI, however the satellite reflectance data did not result as expected, because the degraded area reflected less energy in the red, however the recognition of coverage patterns was observed mainly in area without degradation. The chlorophyll content in the canopies was compared with reflectance obtained with the field spectrometer, and in the reflectance graphics presented particular features. However, the reflectance spectra were better analyzed after applying the information extraction techniques, in which the spectral derivative and the removal of the continuum were efficient to differentiate the areas, confronting with the chemical data

Keywords

• hyperspectral remote sensing
• chlorophyll-a
• Brachiaria decumbens
• reflectance