Analysis of Imaging Quality of New Laser Communication System on Missile in the Aerodynamic Environment

Abstract

We study the influence of altitude and speed on aero-optic imaging quality degradation of new laser communication system “Multi-Aperture Transmission and Diversity Reception” of surface-to-air missile. The 3D modeling and meshing of surface-to-air missile are obtained by ANSYS software. The density field distribution around the optical system was analyzed by FLUENT and the nonuniform refractive-index field around is calculated, in view of the Gladstone–Dale relation. The point spread function (PSF), Strehl ratio (SR), encircled energy, and modulation transfer function (MTF) are provided for the imaging quality evaluation of optical system. The altitude ranges from 0 to 20 km, and the speeds of missile are 5 and 3 Ma. The results show that, at the constant speed, with increase in the altitude, the refraction index and the radius of dispersion spot including 80% energy are gradually decreasing; the SR results and the curve of MTF are gradually increasing, and the PSF is concentrated. At the constant altitude, with increase in the speed, the aerodynamic flow field becomes more and more complex. Therefore, the higher the altitude, the better the receiving quality, and the smaller the speed, the better the receiving quality.