Subpixel mixture modelling applied for vegetation monitoring
Abstract
The NOAA-AVHRR sensor provides daily acquisitions which may be used for vegetation growth monitoring. However, the coarse resolution of these data causes a problem of pixel heterogeneity. The pixel radiometric value is, in fact, a composition of individual responses from the different land covers found within the pixel's surface. In this paper we assume a linear relation. The simultaneous use of NOAA-AVHRR temporal series and of high spatial resolu-tion ground data makes it possible to estimate the pure NOAA reflectances in the visible and near infrared wavelengths for each vegetation type. These val-ues are then combined to compute the NDVI temporal profile which describes the seasonal cycle of the studied crops. The proposed method is applied on the region of Chartres in order to describe the major crops temporal behavior.