In the above equations, we have
:<math> \begin{align}s = |\rho_D - \rho_S| \\s' = |\rho_D - \rho_r|\end{align}</math>
:<math>s' = |\rho_D - \rho_r| </math>Â :<math>L = \frac{s s' \sin^2 \beta'}{s + s'}</math>
:<math>a^{\pm}(\nu) = 2\cos^2 \left( \frac{2n\pi N^{\pm} - \nu}{2} \right), \quad \nu = \phi \pm \phi' </math>