Estimation NDVI using normalized reflectance through GK-2A / AMI data

National Meteorological Satellite Center of Korea Meteorological Administration (NMSC/KMA) launched the Geo-KOMPSAT-2A (GK-2A) / Advanced Meteorological Imager (AMI) on December 2018. GK-2A/AMI contains high spatio-temporal measurements through 16 channels to observe the Earth's surface and environment. In this study, we estimated the Normalized Difference Vegetation Index (NDVI) using this satellite data. We used the Second Simulation of a Satellite Signal in the Solar Spectrum (6S) Radiative Transfer Model (RTM) to at atmospheric correction and kernel-based semi-empirical BRDF modeling in order to remove the anisotropic effect of the surface. Based on this process, we calculated NDVI at 1-day intervals. We performed verification with the Project for On-Board Autonomy - Vegetation (PROBA-V) NDVI. GK-2A NDVI was synthesized on MVC for 10 days to equalize the temporal resolution of the two satellite data. As a result, the RMSE was 0.046, the R was 0.97, and the bias was -0.006. This result shows higher accuracy than other studies. As a result of qualitative analysis, both satellite data showed a similar spatial tendency. In areas where vegetation is abundant, the results of this study are highly expressed compared to the verification data.