An improved method for the retrieval of surface reflectance from EOS/MODIS data

Surface reflectance retrieval is an important step in the data processing chain for the extraction of quantitative information in many applications areas. The aim of this paper is to develop a new method for retrieving surface reflectance and aerosol optical depth simultaneously over both dark vegetated surfaces and bright land surfaces. After applying this new model to the Moderate Resolution Imaging Spectroradiometer (MODIS) data in the Heihe River Basin of China, aerosol optical depth and surface reflectance values of these regions are calculated. The retrieved surface reflectance from MODIS is consistent with measured reflectance from Analytical Spectral Device (ASD) Field Spec spectral radiometer, and the root mean square error (RMSE) are; Band 1 (0.66μm): 0.027; Band 3 (0.47μm): 0.015; Band 4 (0.55μm): 0.017. The R-squared (R2) value reveals a good agreement between MOD09 and retrieved surface reflectance at band 1. The RMSE of the reflectance value differences are quite small; Band 1: 0.031; Band 3: 0.026; Band 4: 0.029.