Annex 1
1 Introduction
2 Basic concepts
2.1 Fresnel ellipsoids and Fresnel
zones
2.2 Penumbra width
2.3 Diffraction zone
2.4 Obstacle surface smoothness
criterion
2.5 Isolated obstacle
2.6 Types of terrain
2.7 Fresnel integrals
3 Diffraction over a spherical Earth
3.1 Diffraction loss for
over-the-horizon paths
3.1.1 Numerical
calculation
3.1.2 Calculation by
nomograms
3.2 Diffraction loss for any
distance at 10 MHz and above
4 Diffraction over isolated obstacles
4.1 Single knife-edge obstacle
4.2 Single rounded obstacle
4.3 Double isolated edges
4.4 Multiple isolated obstacles
4.4.1 Cascaded cylinder
method
4.4.2 Cascaded knife edge
method
5 Diffraction by thin screens
5.1 Finite-width screen
5.2 Diffraction by rectangular
apertures and composite apertures or screens
5.2.1 Diffraction by a
single rectangular aperture
5.2.2 Diffraction by
composite apertures or screens
6 Diffraction over a finitely conducting
wedge
7 Guide to propagation by diffraction
Appendix 1 to Annex 1 Calculation of cylinder parameters
1 Diffraction angle and position of vertex
2 Cylinder parameters
Appendix 2 to Annex 1 Sub-path diffraction losses
1 Introduction
2 Method