Radiowave Propagation: Physics and Applications by Curt Levis & Joel T. Johnson & Fernando L. Teixeira

Author:Curt Levis & Joel T. Johnson & Fernando L. Teixeira [Levis, Curt]
Language: eng
Format: epub
Publisher: Wiley
Published: 2011-06-09T22:00:00+00:00

FIGURE 7.11 Calculation of path clearance.

FIGURE 7.12 Received power relative to free space versus normalized path clearance: PEC sphere (146 MHz, 80 km path, 94 m transmitter height, varying receiver height), knife edge, and reduced reflection coefficient interference.

The horizontal axis of Figure 7.12 is expressed in terms of the ratio of the clearance h to the radius F1 of the first Fresnel zone. In the unobstructed region h is measured, as usual, from the point where the reflection occurs. It can be shown that, for a smooth sphere, this point corresponds to the minimum value of h′/F1 along each path, where h′ is the distance from the path to the surface, perpendicular to the surface. This property was used in calculating Figure 7.12. In Figure 7.12 the abscissa is labeled in h/F1 (dimensionless) units, and the ordinate is the (also dimensionless) ratio of the actual field strength, , to what it would be in free space, .

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.