A new method for modeling the radiative transfer in inhomogeneous three-dimensional media illuminated by a Gaussian beam is described. This approach, called the Spectral Spherical Harmonics Discrete Ordinate Method (SSHDOM), uses the Fourier expansion method to transform the three-dimensional radiative transfer into an one-dimensional equation in the spectral domain, and the Spherical Harmonics Discrete Ordinate Method (SHDOM) for its solution. Specifically, (i) the source function is represented in the spectral domain through a spherical harmonic expansion, (ii) the spectral one-dimensional radiative transfer equation is integrated along discrete ordinates through a spatial grid, and (iii) the solution method is based on the Picard iteration. Both SSHDOM and SHDOM algorithms are implemented in a common computer code.

描述了一种建模高斯光束照射的非均匀三维介质中辐射传递的新方法。这种方法称为“光谱球谐离散离散标准方法（SSHDOM）”，它使用傅立叶展开法将三维辐射传递转换为光谱域中的一维方程，然后使用“球谐离散离散方法（SHDOM）”其解决方案。具体而言，（i）源函数通过球谐展开在谱域中表示；（ii）通过空间网格沿离散坐标积分一维光谱辐射传递方程，并且（iii）求解方法基于在Picard迭代中。SSHDOM和SHDOM算法都在通用的计算机代码中实现。