The cause of lightning is the massive accumulation and release of thunder cloud charge, so the monitoring of thunder cloud charge is direct monitoring, while doppler radar measures cloud thickness, cloud moving speed, direction and distance through radar echo spectrum, which is indirect measurement, and the measured parameters have no direct relationship with the charge of the cloud. Satellite cloud images are observations of infrared radiation over the entire surface of the earth.
Direct measurement is to measure the value of atmospheric electric field, a parameter directly related to cloud charge. This is directly related to the occurrence of lightning, high accuracy, easy to polarity judgment, simple application, easy to understand the parameters;
Indirect measurement is the measurement of other parameters of thunder cloud, th parameters have no direct relationship or little relationship with the occurrence of lightning, so the accuracy is low, the polarity of thunder cloud cannot be distinguished, the application is complex, and there is no intuitively understood parameter value.
