Research on ultraviolet imaging detection of high-speed aircrafts

Ultraviolet spectroscopy analysis of aircraft plume region is a new breakthrough in high-speed aircrafts detection technology. The main difficulty lies in obtaining spectral information and flow field information of aircraft plume. Firstly, based on the high-temperature radiation of high-temperature alumina particles and the secondary combustion theory of unburned fuel, the flow field of the tail flame is simulated. The simulation chamber adopts a variety of solutions and network convergence methods. The temperature, pressure and gas density distribution of the tail flame field can be obtained by simulating the tail flame flow field. Secondly, the atmospheric channel characteristics of ultraviolet detection are studied in this paper. The calculation of spectral irradiance of the plume target and the earth background ultraviolet radiation reaching the pupil of the camera is very important for the design of the detection system. Combining the absorption and scattering characteristics of the atmosphere to the ultraviolet wave band, the ultraviolet imaging detection scheme for the target tail flame is established. For the research of ultraviolet detection channel, the atmospheric radiation transmission software MODTRAN is selected to carry on the preliminary simulation research. The absorption and scattering of all atmospheric molecules and the absorption and scattering effects of aerosols and clouds are calculated by calculating the path transmittance, atmospheric emissivity, single or multiple scattering of solar and lunar emissivity and direct transmission of solar radiation.