Fresnel-Kirchhoff

Ep=ik2πEseiωtObstacleF(θ)eik(r+r)rrdAE_p = \frac{-ik}{2\pi}E_s e^{-i\omega t} \iint_{Obstacle} F(\theta)\frac{e^{ik(r+r')}}{rr'} \,dA

Skewness Factor

F(θ)=1+cosθ2F(\theta) = \frac{1+\cos\theta}{2}

Raius of Fresnel Zones

RnnLλ where 1L=1p+1qR_n \approx \sqrt{nL\lambda} \,\,\,\,\,\,\,\ \textup{where} \,\,\,\,\,\,\,\ \frac{1}{L}=\frac{1}{p}+\frac{1}{q}