Radiative Properties Of TLEs

Transient Luminous Events(TLEs) are large scale optical events occurring at high altitudes with complex ultraviolet, visible, infrared radiation characteristics, which are related to the electrical activity in underlying thunderstorms and has a potential influence on aircraft and spacecraft. In this thesis, research of volume radiation and transferring radiation was carried out with theoretical calculation and example verification based on the Boltzmann equation and the theory of collision, finally TLEs radiation effects on the detection of near space vehicles were discussed. And the main results are as follows:(1) The interaction between gas molecules and electrons that accelerated by the electric field and the physical process of exciting, dissociation, ionization and transition was analyzed according to the collision theory; the calculating methods of firing rate, volume emission and transferring emission were established based on the Boltzmann equation.(2) Volume radiation intensity of typical emission band corresponding to 1PN2, 2PN2, LBH N2, Meinel and 1Nof TLEs were calculated based on simplified model of the quasi electrostatic field in typical discharge conditions. Researches showed that TLEs has ultraviolet to near infrared wavelengths radiation with multiple peak radiation, consisting with observations. The volume radiation intensity of TLEs changed with quasi electrostatic field and atmospheric parameters.(3) Atmospheric spectral transmittance and the volume radiation intensity of TLEs that transfer from different path were discussed by using Pc Mod Win software, which is developed based on MODTRAN atmospheric radiative transfer model. Calculations showed that the volume radiation transferring from the path of view zenith equal and 80 o agreed with what had been observed, which proved the calculating methods of the radiation of TLEs is feasible.(4) The radiation properties of the near space vehicle and TLEs are compared and analyzed, combing with the infrared and ultraviolet detection method of near space flying target, TLEs radiation effects on the detection of near space vehicles are discussed. Researches showed that the radiation of TLEs with multichannel peak radiation had influence on short wave infrared and ultraviolet detection in near space.