REMOTE PHOTOMETRY OF THE ATMOSPHERE USING MICROWAVE BREAKDOWN

A novel method for remote optical diagnostics of the atmosphere at hei ghts 30-60 km is proposed. The method relies on exciting atoms and mol ecules of minority species by electron impact during and following an ionizing microwave pulse injected from a focused ground-based transmit ter. Free electrons produced in the breakdown region are the exciting agents for the atmospheric target molecules. The mixing ratio of the m inority species can then be measured by either detecting the direct em ission from allowed transitions or by utilizing lidar techniques to me asure the excitation level of metastable states. Computer simulations of the intensity of the expected emission, based on kinetic theory of air breakdown, are presented. It is shown that mixing ratios below par ticle per trillion can be detected using microwave heaters with state of the art effective radiation power and modern detection technology.