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RE: continuing education



Ed -- A small correction

> When you calculate G/T from sun measurements [vs cold sky]
> you input the
> solar flux, as precisely measured by an institutional radio
> observatory,
> into the calculations.  If they use linear polarization then your
> measurement will compare directly without a 3 dB correction
> factor.  If
> they made their observation using circular polarization then your
> mesurement will be -3 dB if you are linear.  Its safe to
> assume they use
> circular polarization since the sun radiates in many
> polarizations {and
> probably is randomly polarized}.  Also at VHF and UHF frequencies the
> ionosphere twists the signal via the Faraday Effect.  At 2.4G
> Faraday is
> negligible.  OK?

The bulk of the solar signal is unpolarized. You will get the same value
if you measure it with an vertical, horizontal, diagonal, left, right or
wrong polarization. The power is equal between any two orthogonal
polarizations.

Therefore you don't make any 3dB corrections.

73 de Tom, W3IWI


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