CONTENTS

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