Les,
Galileo (if it is ever built and launched and worked) would just be over Europe, right?
No.
That would leave the rest of the world the ability to use our L band uplink, right?
No.
If we hams are using a dish pointed at the sky with a narrow bandwidth how is that going to interfere with ground receivers some distance from us?
The high EIRP signals will impinge on aircraft. Also, other Hams like ATV will create interference that will not be tolerated for long and all will suffer the consequences.
We would be smart enough to not have the Eagle uplink on the same freq, right?
Wrong, there is almost no place to hide.
And we would design Eagle such that we could (from ground control) move the Eagle receive freq away from any potential conflict with Galileo, right?
No.
And Eagle would be in orbit and operational long before Galileo, right?
No.
And Galileo receivers on the ground will have the ability to cut out any possible interference from us, right?
No.
Seems to me that we are planning to give up the L band (as an uplink) based on a lot of bad assumptions.
The assumption that we are giving up on anything, including L-band, for our satellites (P3E and Eagle) is overblown and untrue.
Rick W2GPS AMSAT LM2232
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of sco@sco-inc.com Sent: Wednesday, September 20, 2006 12:16 PM To: amsat-bb@amsat.org Subject: [amsat-bb] Re: Why do the amsats get more and more complex?
Galileo (if it is ever built and launched and worked) would just be over Europe, right? That would leave the rest of the world the ability to use our L band uplink, right? If we hams are using a dish pointed at the sky with a narrow bandwidth how is that going to interfere with ground receivers some distance from us? We would be smart enough to not have the Eagle uplink on the same freq, right? And we would design Eagle such that we could (from ground control) move the Eagle receive freq away from any potential conflict with Galileo, right? And Eagle would be in orbit and operational long before Galileo, right? And Galileo receivers on the ground will have the ability to cut out any possible interference from us, right?
Seems to me that we are planning to give up the L band (as an uplink) based on a lot of bad assumptions.
Les W4SCO
The answer is in two parts. First, an L-band ground antenna would be too large to disguise as a TVRO dish. Second, there is fear that over the lifetime of Eagle that L-band could become unavailable, particularly in Europe, if the Galileo system is deployed. Galileo would be a primary service and Ham transmissions would likely interfere with low cost commercial receivers.
I don't wish to debate these points. I'm just telling you the reasoning
that
went into not choosing L-band. I assure you that every possibility was considered. Lists were created and discussed on each alternative.
Rick W2GPS AMSAT LM2232
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