Application of wedge diffraction theory to estimating power density at airport humped runways

Shadowing caused by humped runways at some airports significantly attenuates the guidance signals of the microwave landing system as the aircraft approaches the touchdown point. Application of wedge diffraction theory provides an estimate of this effect. A wedge diffraction factor is presented which relates the signal strength in the shadow to that for line-of-sight on a flat runway. Computations are confirmed by measurements at two airports.