Scaling effect on the estimation of chlorophyll content using narrow band NDVIs based on radiative transfer model

The aim of this work is to use narrow band normalized difference vegetation indices to compare the estimations of chlorophyll contents at foliar level and canopy level, through a large number of simulated canopy reflectance spectra under different chlorophyll contents based on PROSPECT model and SAIL model. 10 narrow band NDVIs were selected at the identified ranges that can effectively assess foliar chlorophyll content. We analyzed the correlations between canopy chlorophyll contents and the ten narrow band NDVIs firstly, and then analyze these indices’ sensitivities to all canopy parameters, the adaptation of the 10 narrow band NDVIs used in assessing the canopy chlorophyll content were evaluated finally. We found that only two narrow band NDVIs (i.e., NDVI(875, 725) and NDVI(900,720)) can be applied for the estimation of chlorophyll contents at canopy level.