Vol. 8, No. 2, 180-186, 2009

Abstract
An operational method has been proposed to estimate the leaf area index (LAI) from satellite imagery in the framework of EUMETSAT Satellite Application Facility on Land Surface Analysis (LSA SAF). This study evaluates the performance of the LSA SAF LAI retrieval algorithm when prototyped to VEGETATION/CYCLOPES and MODIS reflectances over Europe for the 2000-2003 period. The results indicate that LSA SAF algorithm retrieves consistent LAI estimates from multiple remotely sensed imagery even when input reflectances present systematic differences. High spatial and temporal consistencies between LSA SAF prototyped LAI and CYCLOPES and MODIS products are found. Differences in LAI between CYCLOPES products and LSA SAF estimates are lower than 0.4 LAI units in terms of RMSE. Larger discrepancies are found when comparing LSA SAF prototyped estimates against MODIS products due, in part, to differences in products assumptions (RMSE ranging from 0.2 up to 0.8 with higher (lower) LSA SAF LAI values compared to MODIS for herbaceous (woody) biomes). Direct validation indicates that LSA SAF prototype estimates achieve similar performances (0.8 and 0.6, respectively) as CYCLOPES and MODIS LAI products. This study constitutes a step forward for the validation and consolidation of the LSA SAF LAI algorithm.

ISSN 1729-3782