For a multipoint obstruction: (111) 2 Cylinder parameters The cylinder parameters illustrated in Fig. 8c) can now be calculated for each of the terrain obstacles defined by the string analysis: and are the positive inter-vertex distances to the obstacles (or terminals) on the transmitter and d1 d2 receiver sides of the obstacle respectively, and: (112) To calculate the cylinder radius use is made of two further profile samples: the point adjacent to on the transmitter side, p: x and: the point adjacent to on the receiver side. q: y Thus the profile indices and are given by: p q = 1 (113) p x – and: = + 1 (114) q y If a point given by or is a terminal, then the corresponding value of should be the terrain p q h height at that point, not the height above sea level of the antenna. The cylinder radius is calculated as the difference in slope between the profile section and p-x y-q, allowing for Earth curvature, divided by the distance between and p q. The distances between profile samples needed for this calculation are: = (115) dpx dx dp – = (116) dyq dq dy – = (117) dpq dq dp – The difference in between the and profile sections is given in radians by: p-x y-q (118) is the effective Earth radius. ae The cylinder radius is now given by: (119) where is the dimensionless knife-edge parameter in equation (32). ν
For a multipoint obstruction: (111) 2 Cylinder parameters The cylinder parameters illustrated in Fig. 8c) can now be calculated for each of the terrain obstacles defined by the string analysis: d1 and d2 are the positive inter-vertex distances to the obstacles (or terminals) on the transmitter and receiver sides of the obstacle respectively, and: (112) To calculate the cylinder radius use is made of two further profile samples: p: the point adjacent to x on the transmitter side, and: q: the point adjacent to y on the receiver side. Thus the profile indices p and q are given by: p = x – 1 (113) and: q = y + 1 (114) If a point given by p or q is a terminal, then the corresponding value of h should be the terrain height at that point, not the height above sea level of the antenna. The cylinder radius is calculated as the difference in slope between the profile section p-x and y-q, allowing for Earth curvature, divided by the distance between p and q. The distances between profile samples needed for this calculation are: dpx = dx – dp (115) dyq = dq – dy (116) dpq = dq – dp (117) The difference in between the p-x and y-q profile sections is given in radians by: (118) ae is the effective Earth radius. The cylinder radius is now given by: (119) where ν is the dimensionless knife-edge parameter in equation (32).
R-REC-P.526-14-201801-I!!MSW-E.docx