Re: [amsat-bb] Atmospheric attenuation at 2.4Ghz?

[Anthony Monteiro <aa2tx@xxxxxxxxxxx>]

Hi Tony,

You can find a chart in "Satellite Communication
Systems," by M. Richharia

I highly recommend the book but I can't find my copy
at the moment to look up the attenuation numbers for you.

I do remember that it is a function of elevation angle and
that it is pretty small at 2.4 GHz.

73,
Tony AA2TX


At 07:54 AM 1/17/2004 -0500, AA2AE wrote:

>All
>
>I was wondering about the effects of the atmosphere at 2.4Ghz. Specifically,
>I thought there might be some degree of signal deffusion or other
>attenuation effects as AO-40's signal penetrated the Earths gaseous
>atmosphere.
>
>I've read that atmospheric attenuation begins to effect the performance of
>mircowave frequencies above 10 Ghz and that water vapor absorption can be
>severe at 24Ghz. But, what about 2.4Ghz? Is there any measueable effect on
>the mode-S downlink we can detect via AO-40?
>
>I would assume attenuation at 2.4Ghz would be relatively small compared to
>the higher microwave frequencies and that the effects are not as pronounced
>from the "top-side" of the atmosphere as with satellite communications, as
>the are with terrestiral propagation.
>
>Any thoughts?
>
>73, Tony - AA2AE
>
>
>
>
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