A computational model for multiple knife-edge diffraction

The derivation of a multiple knife edge attenuation function is described. This exact multiple integral is transformed into a series suitable for numerical evaluation. The series solution is implemented as a computer program capable of calculating the attenuation over a path consisting of up to 10 knife-edges. Theoretical attenuation calculations are compared with observed measurements for a 15-km path containing 5 knife edges. The significance of atmospheric refractivity on multiple knife edge diffraction is discussed, and a means to use this to provide information about the statistical distribution of propagation loss over specific paths is suggested.