Based on the derivation of the formula of channel IR4 albedo,the data including the brightness temperature and the albedo of channel IR4 was applied to analyze a case of the precipitation in summer in Beijing.The results show that channel IR4 albedo will increase and then decrease significantly before the precipitation is generated.Channel IR4 has an earlier feedback on the precipitation than long-wave infrared(IR1) channel and water vapor(WV) channel.In the weak echo phase after heavy precipitation,the bri...