The Calculation of Ground Wave Attenuation in the HF Band Using Program Wagner
Abstract
We present computational test results from a double precision version of the FORTRAN program 'WAGNER'. The potential value of this integral equation technique is its purported ability to model propagation losses over two- dimensional paths through irregular and inhomogeneous terrain. However the numerical integration algorithm can be affected by poor convergence and inaccuracy, particularly at frequencies above the MF band. We have investigated these properties in terms of selected key parameters and have derived empirical criteria governing convergence and physical accuracy. We find that calculations of basic transmission loss using WAGNER are subject to significant limitations at HF frequencies as the terrain becomes irregular and as the conductivity and dielectric constant of the ground both become smaller. On the other hand, the shadow loss due to an obstacle may be reliably calculated by WAGNER on the assumption that shadow loss is independent of ground electrical constants, thus permitting the use of dummy values of conductivity and dielectric constant to ensure that the physical accuracy criterion is satisfied. Computer programs; Ground wave propagation; Attenuation; Transmission loss; Wagner (computer program); Australia.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1987
- Accession Number
- ADA200049
Entities
People
- A. O. Zollo
- R. M. Thomas