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 LoS paths with sub-path diffraction       
 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 
 5     Diffraction by thin screens
       5.1      Finite-width screen
        5.2     Diffraction by rectangular apertures and 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