[amsat-bb] Re: Max range apogee vs perigee

[jmfranke]

The numbers assume the antenna is on the surface of the Earth.  You must add 
the distance from the antenna to the local horizon to the calculated 
figures.  And, there is refraction.

John  WA4WDL

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From: "Pierre van Deventer" <pierrevd at icon.co.za>
Sent: Friday, February 26, 2010 2:31 AM
To: <AMSAT-BB at amsat.org>
Subject: [amsat-bb]  Max range apogee vs perigee

> Bob W7LRD
>
>
> I came across this info, might be of some value.
>
> Ref: The Satellite Experimenters Handbook, Pg 9-6
>
> Max Dist (range) = 2R * arcos [R/(R+h)]
>
> Where R = 6,371 km and
> h = 1,459 km at Apogee (AO-7)
> h = 1,440 km at Perigee (AO-7)
>
> Therefore the maximum possible communication distance via AO-7 at Apogee =
> 7,904 km.
> Therefore the maximum possible communication distance via AO-7 at Perigee 
> =
> 7,861 km.
>
> The difference in range from apogee to perigee appears to be only 33 km.
>
>
> 73, Pierre ZS6BB
>
>
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