[amsat-bb] Re: Planning
kl7uw at acsalaska.net
Sun Apr 29 10:54:57 PDT 2007
At 06:55 AM 4/29/2007, Jeff Davis, KE9V wrote:
>Have you noticed the confluence of satellites scheduled to be launched
>in 2009? With the recent SSETI-ESEO news it seems that there is a good
>chance that P3E, SSETI and maybe even Eagle will fly in the 2009 time
>frame (plus/minus the normal delays).
>While that seems like a long time to have to wait, it also provides
>the opportunity to begin planning a new groundstation that can take
>advantage of the 2009 "Feast of Satellites."
>It's been years since the AO-40 failure and over a decade since AO-13
>went sub-orbital. I can't be the only satellite enthusiast who could
>certainly do with a complete station overhaul?
>I hope we will see much discussion on the -BB about assembling new
>stations, new antennas and accessories. Since a person could invest a
>lot of money on equipment, it would be useful to have some published
>guidelines. Perhaps a series of articles in the Journal and other
>publications will be forthcoming as we all prepare for a new
>generation of satellite fun!
>Just something to think about. Having to wait such a long time for
>these projects to come to fruition is frustrating but it also offers
>enough time to begin saving for new equipment and assembling and
>testing everything required so we are all ready to use the new birds
>when they appear on the horizon.
>73, Jeff KE9V
Jeff and all others thinking about long-term station needs:
One can start by assessing what type of satelllite(s) you desire to
work (or receive).
Then look up the individual satellite project's home page to find
their operating parameters:
orbit type, min/max range, frequencies, power output and antennas.
Once you have the particulars for the satellites you wish to track,
then you need to calculate path-link performance in order to
determine your ground station antenna, receiver and transmitter
requirements. This last part is probably the biggest problem for
most prospective operators.
In the past I (and others) have written some programs to analyze
performance of certain satellites. Most recently I did one for
receiving the Mars Reconnaissance Orbiter, but this can be used (with
a few modifications) for making path-link calculations for any
satellite; here is the link to the Excel spreadsheet:
It is not very fancy and has no macros, but it will provide one with
an idea of what they need on the ground for receiving. To modify
this program to suit another satellite you will need to turn off
"protection" by clicking "tools", "protection", and select "unprotect sheet".
In order for me (or others) to produce a program for predicting
satellite performance (path-link analysis), we will need to know
certain satellite parameters. I have not investigated to see if
enough of these have been established for P3E or Eagle, for one to
produce a specific program. A completely generic program can be
done, which then would place the issue of gathering these parameters
in the hands of the user.
But I guess that such a generic program would have some value even if
some items were "guess-itmates"!
Once you have determined a set of antenna gain, receiver noise
figure, and transmitter power requirements for your ground station,
then it becomes a process of designing a station to accomplish
them: right combos of radios, converters, preamps, cables, antennas,
I know that many wish a complete paper or article suggesting specific
equipment and configurations to accomplish this. But at this point I
suspect that too many things are still subject to change or still in
design, to "nail down".
Ed - KL7UW
BP40IQ 50-MHz - 10-GHz www.kl7uw.com
144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w
DUBUS Magazine USA Rep dubususa at hotmail.com
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