[A-CG36] Terrestrial monitoring using new-generation geostationary satellites

[ACG36-03] Himawari8/AHI land surface reflectance estimation and preliminary evaluation

*Wei Li¹, Kazuhito Ichii¹, Beichen Zhang¹, Yuhei Yamamoto¹, Wei Yang¹, Ram Sharma¹, Hiroki Yoshioka², Masayuki Matsuoka³, Tomoaki Miura⁴ (1.Chiba University, 2.Aichi Prefectural University, 3.Mie University, 4.University of Hawaii, Manoa)

Keywords:Himawari-8 AHI, Geostationary satellite, Land surface reflectance, LEO-GEO inter-comparison, BRDF

Himawari-8 Advanced Himawari Imager (AHI) is a Japanese geostationary meteorological satellite and an onboard sensor. Since Himawari-8 AHI observes the Earth's hemispheres every 10 minutes with multiple spectral bands, the observation datasets are expected to be a new data source for terrestrial monitoring. Estimation of surface reflectance is the first essential step toward terrestrial-monitoring in a quantitative way. In this study, we developed a workflow for atmospheric correction and its evaluation. A look-up table (LUT) method was developed for atmospheric correction based on the Second Simulation of a Satellite Signal in the Solar Spectrum Vector (6SV) Radiative Transfer Model (RTM) for surface reflectance estimation. A kernel-driven Bidirectional Reflectance Distribution Function (BRDF) model was further applied to estimate BRDF parameters and use it to estimate angular corrected surface reflectance. The estimated angular corrected surface reflectance was evaluated by comparing it with the Global Change Observation Mission - Climate (GCOM-C)/Second Generation Global Imager (SGLI). The inter-comparison showed a strong consistency between AHI and SGLI surface reflectance (correlation coefficient r > 0.70).