Spatial and temporal mapping of leaf area index in Alpine pastures and meadows with satellite MODIS imagery

This paper presents an improved algorithm for the retrieval of leaf area index (LAI) from satellite MODIS imagery specifically calibrated for Alpine meadows and pastures. The main features of the proposed algorithm, which is based on the inversion of a radiative transfer model, are: i) the improved spatial resolution (250 meters) with respect to the MODIS standard LAI product, and ii) the tuning of the retrieval system on the spectral characteristics of Alpine meadows and pastures. The analysis of a 10 year time series of LAI maps obtained with the proposed algorithm in comparison with both the MODIS standard LAI product and field measurements confirms the effectiveness of the technique presented for spatially and temporally mapping LAI in Alpine areas at regional scale.