中文摘要：

本文建立镜反射不透明表面下，非均匀光学物性纯吸收性介质内的红外辐射传输模型。红外辐射在折射率连续变化的介质内沿曲线传输。将非均匀介质沿厚度方向离散成n个物性均匀的等温微层，每个微层内辐射沿直线传播，光滑曲线传输路径即离散成首尾相连的折线系列。采用多层辐射传输模型，利用射线踪迹法建立非均匀介质内的红外辐射传输模型。在多层模型中，相邻两微层间的界面引入折射／全反射判据，避免了界面处的积分奇异现象和原本不存在的界面反射现象。

英文摘要：

An infrared radiation transfer model is developed for an inhomogeneous purely absorbing medium with opaque specular surfaces. Infrared radiation transfers in a curve within a medium having a continuously variable refractive index. The inhomogenous medium is divided into n homogenous isothermal sublayers and the radiation transfers in a straight line in each sublayer. Thus the curve trajectory for radiation is discretized as a series of polylines. Using a multilayer radiative transfer model, an infrared radiation transfer model is built for the inhomogenous medium by a ray-tracing method. The multilayer model introduces a criterion for refraction/total reflection at the interfaces between neighboring sub-layers, avoiding the integral singulartity and reflection at physically inexistent interfaces.