Re: NEC-LIST: uneven ground

Dr. B:

This problem has been considered by J. K. Breakall, et al. in an IEEE
Trans. AP paper published the same year that we last had the AP-S
symposium in Seattle. We successfully modeled the situation using NEC
to get the currents under the assumption of a locally flat earth, and
then used those currents as inputs to NEC-BSC to handle the
diffraction over the irregular terrain. This tested out well with data
we took in Utah on a project with Dick Adler. Gerry Burke tried some
other modeling techniques (e.g., GO, PO), but these results are not
published (to my knowledge) except in project reports for the
Navy. One of the profs at the Naval Postgraduate School used a path
integral method to model the same geometry and also had success. His
paper in Trans. AP won an award. It was published slightly before the
Breakall, et al. paper, which Jim and I proofed while enroute to the
Seattle AP-S symposium.

The hybrid method (MoM and UTD) has been used by others with success
(see the references in the Breakall, et al. paper. I am sorry I cant
give you the exact cite. If Jim, Dick Adler, or Doug Werner get this
msg, they may be able to provide the cite, as they were co-authors of
the paper.

Hope this helps.

Regards,

George Hagn
Consultant
4208 Sleepy Hollow Road
Annandale, VA 22003-2046
(703) 941-7663

P.S. Give me a call if you have trouble locating the Breakall, et al.
paper.
Received on Tue May 30 2000 - 14:20:57 EDT