A Comparison of Leaf Area Index Maps Derived from Multi-Sensor Optical Data Acquired over Agricultural Areas

The objective of this study is to retrieve and compare Leaf Area Index (LAI) maps from temporal series of SPOT, IKONOS and MERIS images acquired, from 2006 to 2008, over an agricultural site in Southern Italy. Results show that the root mean square error (RMSE) of LAI derived from MERIS data is approximately 1 m2 m-2, slightly larger than the one obtained by using SPOT and IKONOS data. In addition, LAI retrieved from MERIS data tends to underestimate LAI retrieved from SPOT and IKONOS data, particularly at low LAI values. Nevertheless, the paper gives examples highlighting the strength of MERIS with respect to SPOT and IKONOS data in providing long and dense temporal series of LAI maps suitable to feature the temporal evolution of vegetation growth at regional scale.