$\begin{split} {{\bf{\varepsilon }}_{\rm surf}} \; &= \left[ {1 - \int {{\bf{f}}({\theta_{\rm{i}}},{\phi _{\rm{i}}},{\theta_{\rm{r}}},{\phi_{\rm{r}}},\lambda )\cos ({\theta_{\rm{i}}}){\rm{d}}{\varOmega_{\rm{i}}}} } \right] \cdot {{\bf{\varepsilon }}_0} \\ & = \left[ {\begin{array}{*{20}{c}} {1 - \int {{f_{00}}({\theta_{\rm{i}}},{\phi _{\rm{i}}},{\theta_{\rm{r}}},{\phi_{\rm{r}}},\lambda )\cos ({\theta_{\rm{i}}}){\rm{d}}{\varOmega_{\rm{i}}}} } \\ { - \int {{f_{10}}({\theta_{\rm{i}}},{\phi _{\rm{i}}},{\theta_{\rm{r}}},{\phi_{\rm{r}}},\lambda )\cos ({\theta_{\rm{i}}}){\rm{d}}{\varOmega_{\rm{i}}}} } \\ { - \int {{f_{20}}({\theta_{\rm{i}}},{\phi _{\rm{i}}},{\theta_{\rm{r}}},{\phi_{\rm{r}}},\lambda )} \cos ({\theta_{\rm{i}}}){\rm{d}}{\varOmega_{\rm{i}}}} \\ { - \int {{f_{30}}({\theta_{\rm{i}}},{\phi _{\rm{i}}},{\theta_{\rm{r}}},{\phi_{\rm{r}}},\lambda )\cos ({\theta_{\rm{i}}}){\rm{d}}{\varOmega_{\rm{i}}}} } \end{array}} \right] \\ & = \left[ {\begin{array}{*{20}{c}} {1 - \int {{f_{00}}({\theta_{\rm{i}}},{\phi _{\rm{i}}},{\theta_{\rm{r}}},{\phi_{\rm{r}}},\lambda )\cos ({\theta_{\rm{r}}}){\rm{d}}{\varOmega_{\rm{r}}}} } \\ { - \int {{f_{10}}({\theta_{\rm{i}}},{\phi _{\rm{i}}},{\theta_{\rm{r}}},{\phi_{\rm{r}}},\lambda )\cos ({\theta_{\rm{r}}}){\rm{d}}{\varOmega_{\rm{r}}}} } \\ { - \int {{f_{20}}({\theta_{\rm{i}}},{\phi _{\rm{i}}},{\theta_{\rm{r}}},{\phi_{\rm{r}}},\lambda )\cos ({\theta_{\rm{r}}}){\rm{d}}{\varOmega_{\rm{r}}}} } \\ { - \int {{f_{30}}({\theta_{\rm{i}}},{\phi _{\rm{i}}},{\theta_{\rm{r}}},{\phi_{\rm{r}}},\lambda )\cos ({\theta_{\rm{r}}}){\rm{d}}{\varOmega_{\rm{r}}}} } \end{array}} \right] \end{split} $![]() ![]() | (6) |