Proc. SPIE. 9796, Selected Papers of the Photoelectronic Technology Committee Conferences held November 2015
KEYWORDS: Thermal modeling, Performance modeling, Infrared radiation, Skin, Radiation effects, Atmospheric modeling, Solar radiation, Temperature metrology, Data modeling, Solar radiation models, Far infrared, Mathematical modeling
The characteristic of the self-infrared radiation of airplane-skin is very important for the stealth performance of airplane. Based on the theory of the airplane-skin temperature field, the distribution of the atmospheric temperature field and the principle of the black-body radiation function the self-infrared radiation model was established. In specified flight conditions, the influence of the atmospheric temperature, the speed of flight, the emissivity and the sight angle detection on the self-infrared radiation of the airplane skin were analyzed. Through the simulation of infrared radiation, some results under different flight states are obtained. The simulation results show that skin infrared radiation energy mainly concentrate on the far infrared wavebands, and various factors have different effects on the infrared radiation of skin. This conclusion can help reduce the infrared radiation and improve the stealth performance of airplane in the engineering design and the selection of flight conditions.
Imaging unevenly is a problem to work out in laser display. The cause of imaging unevenly is analyzed in the paper firstly. In order to get even illumination, we use rotating polygon mirror with two-dimensional scanning and lens array to make the intensity distribution of Gaussian function become approximate even distribution. In order to reduce speckles, a rotating diffuser is used in our laser display system to produce the maximum speckle reduction with the minimum number of distinct phase Patterns. Finally the method is experimentally verified by taking example of green light.
The model of electromagnetic-wave propagation in an inhomogeneous plasma sphere was built up, and the electromagnetic-wave refraction and absorption attenuation were discussed. Theoretical calculation and numerical simulation indicate that electron density in the inhomogeneous plasma sphere changes more quickly, the more electromagnetic-wave trajectory is deflected, and energy attenuation is more obvious, the better stealth effect takes.