Estimation Of Fractional Snow Cover From Fy-4a/Agri

China's new generation of geostationary weather satellite, FengYun-4A (FY-4A) carrying the Advanced Geosynchronous Radiation Imager (AGRI) was launched on December 1 2016 and its data became publicly available on March 12 2018. The availability of high temporal observation at visible, near infrared, short-wave infrared and long-wave infrared bands over stable snow covered areas in China inspired this study to investigate the feasibility of FY-4A AGRI to estimate fractional snow cover. In this preliminary study, we present the multiple end-member spectral mixture analysis on FY-4A AGRI's 5-band reflectances for snow covered area estimation. The end-members were extracted automatically from multispectral images and typical end-members were selected using the vector length. To account for the reflectance variation due to sun-target-sensor geometry, the end-member extraction and selection and subsequent estimation were implemented by the 5 degrees x5 degrees spatial window. The fractional snow cover estimates were evaluated by using reference data from corresponding Landsat-8 Operational Land Imager (OLI)'s 30- m resolution observations. The outcome indicated that FY-4A AGRI's fractional snow cover agrees well with Landsat-8 OLI's 30 m estimates. Comparisons showed that root mean squared error of FY-4A AGRI fractional snow cover ranges from 0.10 to 0.16 with R2 exceeding 0.7.