Networking Observation And Data Analysis Of Corona Current Near The Ground

Based on the theory that intense electric field beneath thunderstorms can produce corona discharge at the tip of grounded metal point, a corona current measuring instrument was developed by us. Using wireless data transmission technology, the multi-station wireless networking observation of corona current was implemented, and this corona measuring system had been used to observing summer thunderstorms in south of our nation for 4 months at"Guangzhou Field Experiment Site for Lightning Research and Testing". The results of field experiments showed that the corona current network observation system can operate normally in a certain region.The records of corona current and synchronous environmental electric field were also analyzed in detail. The threshold values of positive and negative environmental electric field for initiation of corona current were obtained, and the relation between corona current and environmental electric field were determined, the results are showed fellow: the onset value of electric field to produce corona current in negative environmental electric field is -4kV/m, and in positive environmental electric field that is 3.5kV/m; the relation between (negative and positive) corona current and (negative and positive) environmental electric field is respectively I=-0 .00585E(E-4)and I = 0 .009E(E-3.5). The analysis results also showed that the intensity of environmental electric field can be retrieved factually and accurately from corona current measurement data. The multi-station wireless networking observing system of corona current can apply to observation and prediction for thunderstorm replacing average atmospheric electric field instrument in a certain area. Therefore, corona current network measuring system has important applications in thunderstorm observation and forecast.In order to analyze the influence of environment on corona current measurement result, a electrostatic field model was simulated, and the results showed that the influence of surface feature on the electric field near the tip of the sensors can be characterized by the ratio between horizontal distance"d"between sensor and surface feature and the height difference"Δh"between the two. The influence of surface feature on the electric field near the tip of the sensors reduced to a minimum when the value of d/Δh greater than 2.25. This will provide a Theoretical foundation for continuing the development of corona current networking technologies and methods.