基于坐标变换法的红外成像模型

Infrared Imaging Model Based on Coordinate Conversion

针对气动光学传输效应,本文提出一种用坐标旋转法追迹空间任意若干条光线得到光学传递函数(OTF)来计算成像的模型。该方法根据几何光学成像和坐标旋转变换原理,采用基于计算流体力学(CFD)网格的超高声速流场密度数据建立了成像模型,模拟出了流场的降晰效应,并且对仿真结果进行了对比分析。实验结果表明,该模型在一定的精度内反映了现有的气动光学降晰现象。最后探讨了模型的精度及工程应用的意义。

To simulate and calculate ＂the aero-optical transfer effects＂, an infrared imaging model was presented for applying the coordinate conversion method to trace any light in the space to figure out ＂the Optical Transfer Function （OTF）＂ and ＂the images＂. Based on the principles of geometry optical imaging and coordinate conversion, this method utilizes the density data based on the Computational Fluid Dynamics （CFD） grids of the hypersonic flow field to establish the model and emulate the blur effects of the field. And the results were contrasted and analyzed. The experiment results indicate that the model can reflect most of the known aero-optical blur phenomena in definite bound of precision. At last, we probe and discuss the precision and the significance of engineering application of the model.