[Estimation models of rice LAI and chlorophyll content based on MOD09]

The MODIS (moderate-resolution imaging spectroradiometer) surface reflectance product MOD09, which was strictly corrected by NASA, can be widely applied to monitor the change of land vegetation. In this paper, a quasi and synchronous experiment of MODIS sensor was performed, and the rice leaf area index (LAI) and chlorophyll content (Chltot) were measured. The relationships between the vegetation indices (VIs) derived from MOD09 and the rice LAI and Chltot were analyzed, and the estimation models were established. The VIs values derived from MOD09 were higher than those in the first three bands of MOD09, and EVI value was lower than NDVI value. In comparing with other Vis, EVI had a better relationship with LAI at different rice growth stages. MOD09-EVI was selected to construct the estimation model of rice LAI, and validated by other in situ sampling plot data to be more precise, suggesting MOD09-EVI was the best index to monitor rice LAI. There was a significant correlation between MOD09-Red band and Chltot at early and medium rice growth stages. The estimation model of rice canopy Chltot based on MOD09-Red band was established and validated, and no models were significantly efficient, except the estimation model of Chltot at booting stage.