An Easy Algorithm for Solving Radiative Transfer Equation in Clear Atmosphere

An accurate and rapid method for solving radiative transfer equation is presented in this paper. According to the fact that the multiple scattering component of radiance is less sensitive to the error of phase function than the single scattering component is, we calculate the multiple scattering component by using delta-Eddington approximation and the single scattering component by solving radiative transfer equation. On the ground, when multiple mattering com-ponent is small, for example, when the total optical depth τ is small, the accurate radiance can be obtained with this method. For the need of the space remote sensing, the upward radiance at the top of the atmosphere is mainly studied, and an approximate depression is presented to correct the multiple scattering component. Compared with the more precise Gauss-Seidel method, the results from this method show an accuracy of better than 10% when zenith angle θ < 50o and τ ≤ 1. The computational speed of this method is, however, much faster than that of Gauss-Seidel method.