RECOMMENDATION ITU-R P.526-8 - Propagation by diffraction
Annex 1
1 Introduction
2 Fresnel ellipsoids and Fresnel zones
3 Diffraction over a spherical earth
    3.1 Numerical calculation
    3.1.1 Influence of the electrical characteristics of the surface of the Earth
    3.1.2 Diffraction field strength formulae
    3.2 Calculation by nomograms
4 Diffraction over obstacles and irregular terrain
    4.1 Single knife-edge obstacle
    4.2 Finite-width screen
    4.3 Single rounded obstacle
    4.4 Double isolated edges
    4.5 General method for one or more obstacles
    4.6 Finitely conducting wedge obstacle
5 Obstacle surface smoothness criterion