The Fengyun-3E and Fengyun-4B meteorological satellites and their ground application systems have officially launched operations after a six-month trial run. Fengyun-3E is the fifth of China's Fengyun-3 series of satellites in polar orbit, and the world's first meteorological satellite in sun-synchronous orbit. Fengyun-4B is China's new-generation geostationary meteorological satellite. During the trial run, its observations played an important role in natural disaster emergency response, such as for heavy precipitation, polar vortices and typhoons.