All,
Since ground conductivity is an important parameter for our 160m efforts
and it has been discussed previously on this reflector, I thought I'd
mention that an interesting paper appeared in the recent IEEE
Transactions on Broadcasting (Vol 55, No 2, June 2009). The list of
authors, along with the abstract, is given below.
Carl K9LA
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Alternative Methods to Obtain Ground Conductivity
Raúl Ruiz, José Manuel Riera, Member, IEEE, and Jorge Montoya
Abstract - The radio planning of systems in lower frequency bands, such
as LF and MF, makes use of ground conductivity at these frequencies, as
it determines the attenuation of the surface wave, characteristic of the
propagation in these bands. In this paper, three alternative methods to
obtain an estimation of the conductivity are presented and compared. The
first one is based on measurements of the electric field strength
generated by AM transmitters. Although it is considered the most
accurate, it is also the most expensive as it requires extensive and
detailed measurements that are not always feasible. The second method
relies on several terrain characteristics that are known to be related
to the conductivity, and uses reference conductivity values from similar
areas. The third method makes use of remote sensing data, information
that is readily available worldwide at low cost. The methods are
compared through their application in a research work carried out in
Mexico. The results show that these approximate methods can yield
results with reasonable accuracy, when compared with the results
obtained from field strength measurements.
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