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Re: radio propagation



At 20:31 4/16/01 -0700, you wrote:
I was looking through some of my father's ham radio books
recently, and came across something I didn't understand.
/snip/
They assume there's 100% reflection from the ground,
which makes sense, since it's a conductor. When the
radio waves hit the ionosphere, however, they describe
some behavior that I don't understand. Waves that strike
the ionosphere close to normal can be 100% transmitted,
while beyond some critical angle they're partially
transmitted and partially reflected. /snip/


For what it's worth, this note reminds me of visiting the
Rutherford-Appleton Lab and during the course of a conversation
mentioning the several reflecting layers in the ionosphere.
My kindly respondent pointed out that it is better not to visualize
a reflection but rather an absorption and refraction which can
bend signals of various frequencies at different rates.
The charged layers between 100 and 300 km high begin to recombine
after sunset, lowest fastest, so that especially in daytime,
signals may need to penetrate a lower layer in order to refract
in another.

brian whatcott <inet@intellisys.net> Altus OK
Eureka!