3.1.1. Remote sensing Datasets

This study takes the L1 level data obtained by the multi-channel scanning imaging radiometer of the FY-4A satellite [34,35] as the satellite spectral image data. The FY-4A satellite is a new generation of China's geostationary meteorological satellite, and it is equipped with various observation instruments including the Advanced Geosynchronous Radiation Imager (AGRI). As shown in Table 1, AGRI has 14 spectral bands from visible to infrared (0.45–13.8 μm) with a high spatial resolution (1 km for visible light channels, 2 km for near-infrared channels, and 4 km for remaining infrared channels) and temporal resolution (full-disk images at the 15-min interval).


**Table 1.** The description of spectral image information.

The daily data from January to December 2020 were used for the training process, and the daily data from June to August 2020 were used for testing. The daily data are sampled from 12:00 in the satellite's time zone, to maximize the visible area in the image.
