Owen Duffy wrote:
Roy Lewallen wrote in news:12tpng510pvr140
@corp.supernews.com:

It's not clear what the objective is. NEC and EZNEC have the ability to

This is about measurement in the field of emission field strengths, and
techniques for coming up with a single number representing the emission
field strength on a particular frequency at a particular location.

I understand that, but "representing" in what way -- an average,
weighted average, RMS, probability density, something else? And what
would it mean? Is it supposed to tell how much interference will be
created for the overall community? Will an antenna with a narrow beam
pointing straight up give the same number as one with a narrow beam
pointing horizontally, or are the data for the axes weighted differently?

This is a means of data reduction, in which the result has less
information than the original data. 3D field strength data *does*
represent the emission field strength, but any summation and consequent
reduction represents less information than this.

I'm not saying that industries or the regulatory agencies won't use
something like this to "prove" whatever they need to prove -- but it
should undergo some critical scrutiny to see just what its meaning
really is.

After all, half the children in the schools are below average!

Roy Lewallen, W7EL