Potencial de utilização de produtos atmosféricos do sensor MODIS/TERRA, para correção atmosférica de imagens AVHRR/NOAA.

Abstract

In the attempt to obtain the real reflectance of ground surface, in channels 1 and 2 of AVHRR sensor, was performed the atmospheric correction of two NOAA images, based on atmospheric data supplied by the MODIS sensor, considering the spatial and temporal variability of these parameters. The system SCORADIS, based on the radiative transfer model called 5S, was adapted to read images having values of aerosols optical thickness, water vapor content and ozone contents corresponding spatially to each pixel of a AVHRR/NOAA image. Four distinct methodologies were used to define the images of atmospheric parameters. Coherent results were obtained using atmospheric data from MODIS, indicating that the scattering and absorption effects were correctly eliminated from the NOAA images in the two dates considered. The difference between the NDVI calculated with corrected and non-corrected images was up to 80%, showing the importance of using corrected images in applications based on multitemporal images. There was not observed difference among the four methodologies applied to define the atmospheric data used in the atmospheric correction system due, maybe, to the magnitude of the values and to the atmospheric conditions of test-area.