An error and sensitivity analysis of atmospheric resistant vegetation indices derived from dark target-based atmospheric correction

An error and sensitivity analysis was conducted to investigate the capabili ties of the atmospheric resistant vegetation indices (VIs) for minimizing " residual aerosol" effects. The residual aerosol effects result from the ass umptions and characteristics of the dark target (DT) approach used to estim ate aerosol optical properties in the atmospheric correction scheme (referr ed to as the dark target-based atmospheric correction, DTAC). The performan ces of two atmospheric resistant VIs, the atmospherically resistant vegetat ion index (ARVI) and enhanced vegetation index (EVI), were evaluated and co mpared with the normalized difference vegetation index (NDVI) and soil adju sted vegetation index (SAVI). The atmospheric resistant VIs successfully mi nimized the residual aerosol effects, resulting in a 60%, reduction of the errors from the NDVI and SAVI when a proper aerosol model was used for the estimation and correction of aerosol effects. The reductions were greater f or thicker aerosol atmosphere (larger aerosol optical thickness, AOT). The atmospheric resistant VIs, however, resulted in having larger bias errors t han the NDVI and SAVI when an improper aerosol model was used. The applicat ion of atmospheric resistant VIs to the DTAC-derived surface reflectances i s exactly what is being carried out by the Moderate Resolution Imaging Spec troradiometer (MODIS) VI algorithm. These results raise several issues for the effective, operational use of the DTAC algorithm and atmospheric resist ant VIs, which are addressed in this paper. (C) 2001 Elsevier Science Inc. All rights reserved.