September 2025 | Technical Report NTIA TR 25-580
A Comparative Analysis of Multiple Knife-Edge Diffraction Methods
Cite This Publication
Nicholas DeMinco, Paul M. McKenna, and Robert Johnk, “A Comparative Analysis of Multiple Knife-Edge Diffraction Methods,” Technical Report NTIA TR 25-580, U.S. Department of Commerce, National Telecommunications and Information Administration, Institute for Telecommunication Sciences, September 2025.
Nicholas DeMinco 
, Paul M. McKenna , and Robert Johnk
Abstract:
The results of a thorough comparative analysis of alternative graphical prediction methods for multiple knife-edge diffraction are presented and compared to the method developed by Vogler. The Vogler multiple knife-edge diffraction loss is rigorous and verified with measured data, but too computationally intensive for use in a propagation model that predicts area coverage over irregular terrain. Mathematical algorithms were developed for alternative graphical prediction methods for diffraction paths with up to six knife edges, resulting in methods that are many orders of magnitude faster. This is important for use in propagation models that predict area coverage over irregular terrain for many radial directions from the transmitter. A technique for selecting the best alternative method is proposed. Graphical techniques and mathematical algorithms are also described. Comparisons of the Vogler method to the alternative methods are included. Some comparisons to measured data are also presented.
Keywords: multiple knife-edge diffraction; electromagnetic wave propagation; diffraction fading; non-line-of-sight (NLOS); radio frequency propagation; Vogler method
For technical information concerning this report, contact:
Nicholas DeMinco
Institute for Telecommunication Sciences
(720) 484-4848
ndeminco@ntia.gov
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Funding Information
Performing Agency
U.S. Department of Commerce
National Telecommunications and Information Administration
Institute for Telecommunication Sciences
325 Broadway
Boulder, CO 80305
https://ror.org/00mj5bc69
Funding Agency
U.S. Department of Commerce
National Telecommunications and Information Administration
Herbert C. Hoover Building
14th & Constitution Ave., N.W.
Washington, D.C. 20230
https://ror.org/032241511
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