where ''F(x)'' is the Fresnel Transition function:
:<math> F(x) = 2j \sqrt{x} e^{jx} \int_{\sqrt{x}}^{\infty} e^{-j\tau^2} \, d\tau </math><!--[[File:frml12.png]]-->
In the above equations, we have
:<math> s = |\rho_D - \rho_S| </math>
Â
:<math>s' = |\rho_D - \rho_r| </math>
Â
:<math>L = \frac{s s' \sin^2 \beta'}{s + s'}</math>
Â
:<math>a^{\pm}(\nu) = 2\cos^2 \left( \frac{2n\pi N^{\pm} - \nu}{2} \right), \quad \nu = \phi \pm \phi' </math>
Â
<!--
[[File:frml10.png]]
[[File:frml13.png]]
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where ''N<supmath>±N^{\pm}</supmath>'' are the integers which most closely satisfy the equations 2''n''π''N<supmath>±</sup>'' 2n\pi N^{\pm} - &\nu; = ±&\pm \pi;</math>.
=== SBR As An Asymptotic EM Solver ===