A Pixel-by-Pixel Atmospheric Correction Algorithm for MODIS Data Based on Look-up Table

Based on the 6S radiation transfer model,the influences of aerosol optical depth,solar zenith,sensor zenith and ground altitude changes on atmospheric corrected reflectances were calculated.The 6S model's sensitivities to these four parameters were discussed.A new correction algorithm based on look-up table was introduced.The look-up tables of correction parameters for different aerosol optical depth,solar zenith,sensor zenith and ground altitude values were established by the 6S model offline computation.Each pixel of MODIS data was corrected by interpolation from the look-up tables to get surface reflectance.The comparison results between our method,online method and parameter-uniform method show that the result of our method was closed to that of online method,which indicates that our method effectively reduces the influence of parameters spatial heterogeneity on atmospheric correction.