[amsat-bb] Re: Bill Ress - N6GHz - Board Candidate - OperatingSurvey
kl7uw at acsalaska.net
Tue Jul 22 23:04:31 PDT 2008
At 04:11 AM 7/22/2008, Andrew Glasbrenner wrote:
>Some replies to Ed's comments:
>>The Intelsat should be much less expensive:
>Let me clarify this some. It is -not- a free ride. Intelsat will
>charge us for the loss of operational time for every kg of
>stationkeeping fuel they offload to accomondate our extra mass.
>There may be some recurring expenses as well.
>>All you provide is RF, antennas, and a communication processor.
>The good stuff.
>>But the location is specified by Intelsat so only one-third of the
>>earth is covered. Which third do you chose for satellite #1. For
>>whole-earth coverage you need rides to three locations 120-deg
>>longitude apart. Far north latitudes will probably not get
>>coverage due to low angles to GEO.
>>For my location at 60.7 latitude the GEO path is 21 degrees
>>elevation due south and is lower as you move east or west.
>We most likely would not be dealing with any sort of spot beam and
>the antennas should be broadbeamed enough so that there is no reason
>to assume 1/3 instead of almost 1/2. If you could work AO-10, AO-13,
>or AO-40 near the horizon, the same would likely be true for
>Intelsat. What would be different is we each could dedicated a fixed
>antenna with no rotor for ground side, and if you live surrounded by
>100' pine trees like I do, you can find an open hole to point through.
>>So continuing with Eagle offers world coverage over a couple days
>>of orbiting. GEO stays in one position.
>While this will maybe make some DXers feel less fulfilled than a
>HEO, it's my hope that it will attract 10x their number in other
>users. A GEO knocks 500$ of the top of everyone's station budget
>right out of the gate...no az-el rotor. Think of the traffic that is
>likely to be attracted to this...24/7 amateur coverage with set and
>forget antennas over 1/2 the earth. No Doppler tuning. Practically
>fixed gain requirements. We may have to find a way to manage the
>data and repeater system links that will inevitably show up. My gut
>suspicion is we won't be able to afford enough bandwidth on the
>first iteration for the users that may come out of the woodwork. If
>we could just get all the users to support the program...
>>I will see you in Anchorage, Drew!
>The YL and I will be in Anchorage on Saturday evening, then in
>Seward and Whittier until Thursday or so. I'm looking forward to
>meeting and speaking with all of ya'll!
>73, Drew KO4MA
I probably over simplified the savings.
MY point on viewing a GEO is if it is centered over the east coast of
the USA it will be below my horizon. If it is over Europe or central
Asia, again no view for anyone on the West Coast of the USA. I have
extensive experience with setting up c-band satellite dishes in
Alaska and the limits of how far east one can view them. Of course a
GEO stationed from Japan to California will be accessible though at
the extreme ends the elevation angle will be around 5-degrees and my
trees mask the sky at least to 10-degrees. No Holes in the solid
forest up here.
Whereas a HEO travels over the pole so lots of high elevation view
angles for norhern stations. Less for southern hemisphere,
though. GEO is more equal on that issue.
I'm sure that a GEO will be very popular due to the simple ground
station set up. I only hope that if we can get one up that I will
have a view of it. The only way to assure world wide use with GEO's
is to launch three of them spaced around the earth separated by
120-degrees of longitude. So the politics are more sticky for the GEO.
At this point I will be happy with a linear translator satellite in
MEO, HEO, or GEO.
73 Ed - KL7UW
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