Research On Infrared Radiation Characteristic Of Object Under Sky And Sea Background

In this thesis, the transmittance, solar irradiance, sky radiation and the radiation of variations surfaces for different observing altitude and different time are calculated by Modtran based on the theory of heat transfer and infrared radiation. Different sea grids are generated according to the Jonswap spectrum for different situations. The spectrum characteristics of the sea for scattering the backgound radiation of the sun and sky is studyed, and the infrared radiation of the sea itself is also calculated.With the radiation values mapped to each pixel on the detector, the radiant heating map can be obtained for the waveband of 3~5μm and 8~12μm. The aerodynamic heating effects on the target temperature is considered and the characteristics of compressible flow around the missile are calculated by FLUENT. The formula for calculating the temperature field on the object surface is founded using node network technique, considering background radiation, heating conduction between different facets of target and the aerodynamic heating effects. The temperature distribution on the surface of the object is calculated with different flight speed, solar radiation, aerodynamic heating, sky radiation and sea radiation, respectively. The radiation field of the object is also calculated under various conditions. Finally, both of the distribution of object temperature and infrared radiation intensity are displayed.