Modification of the dielectric constant of atmosphere for high power microwave propagation with dynamic method

When a high power microwave pulse propagates through the atmosphere, the ionization is expected to occur and produces plasma, and dielectric constant and refractive index of air will change. This paper introduces the dielectric constant of isotropy plasma in primary theory. It presents the influence of collision frequency between electron and gas molecule on the dielectric constant of air based on Maxwell's distribution of velocity. The air dielectric constant in high power microwave propagation in atmosphere and its correction coefficient are introduced by the method of dynamics.The correction of coefficient relate to the frequency and collision frequency. When the ratio of them is very big, the correction of coefficient approximate 1, when the ration of them is small, it approximate