Abstract
Solar zenith angle (SZA) dependence of NDVI from NOAA AVHRR data is clarified by the simulation using LOWTRAN7 based on 10 atmospheric models and 4 surface models. In the simulation, the effect of SZA to radiative transfer is taken into account. It becomes evident that NDVI decreases and NDVI contains much path radiance in larger SZA condition. It can be concluded that in a limited condition when the atmospheric condition is uniform, NDVI with SZA less than 80° is correctable by an approximated formulation of SZA dependence of NDVI (5th. order polynominal of cos (SZA) ) . For more precise correction, it is necessary to estimate atmospheric condition.
