Function rfcalcs::fresnel::fresnel_kirchoff_diffraction_param

pub fn fresnel_kirchoff_diffraction_param(
    freq: Frequency, 
    d1: Distance, 
    d2: Distance, 
    h: Distance
) -> f64

fresnel_kirchoff_diffraction_param Calculates the Fresnel-Kirchoff Diffraction parameter d1 and d2 are the distances between the "knife edge" impingement and the transmitter/receiver h is the impingement, where -ve is below LoS and +ve is above LoS https://en.wikipedia.org/wiki/Kirchhoff%27s_diffraction_formula https://s.campbellsci.com/documents/au/technical-papers/line-of-sight-obstruction.pdf