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<div dir="ltr" data-setdir="false">Interference would be rare, and momentary.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">OK, the bird goes though a 360 deg arc in about 80 minutes.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">So in a typical overhead pass that's about 4 deg a min..</div><div dir="ltr" data-setdir="false">( Yes, a lot of variables in that equation! )<br></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">The antenna beam is 6 deg if we allow for the -10 dB points.</div><div dir="ltr" data-setdir="false">So 90 seconds would put the 2nd bird well out of the pattern from the</div><div dir="ltr" data-setdir="false">ground station.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Lots of orbits, a parallel orbit is not impossible, but in most cases they</div><div dir="ltr" data-setdir="false">would only be in common view of the ground dish for a minute or so.</div><div dir="ltr" data-setdir="false">I'll let someone else do this calculation. Take two LEO Birds, and when</div><div dir="ltr" data-setdir="false">looking from a common point on the ground, how often do they pass within</div><div dir="ltr" data-setdir="false">6 deg of each other? Not often I suspect. Kent WA5VJB<br></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"><br></div><div><br></div>
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On Friday, February 14, 2020, 1:17:53 PM CST, Michelle Thompson <mountain.michelle@gmail.com> wrote:
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<div><div id="ydpd08fb6b4yiv6188454366"><div><div dir="ltr">Good point on frequency management.<br clear="none"><br clear="none">We plan to use (up to) the entire 10MHz amateur allocation. <br clear="none"><br clear="none">Gateway appears to be using less.<br clear="none"><br clear="none">Given that one can model this as a narrowband interferer to a broader band signal, in your opinion, can we accept or ignore the potential interference?<br clear="none"><br clear="all"><div><div class="ydpd08fb6b4yiv6188454366gmail_signature" dir="ltr"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr">-Michelle W5NYV<br clear="none"><br clear="none"><div dir="ltr"><br clear="none"></div></div></div></div></div></div></div></div></div><br clear="none"></div><br clear="none"><div class="ydpd08fb6b4yiv6188454366yqt0173493445" id="ydpd08fb6b4yiv6188454366yqt66897"><div class="ydpd08fb6b4yiv6188454366gmail_quote"><div class="ydpd08fb6b4yiv6188454366gmail_attr" dir="ltr">On Fri, Feb 14, 2020 at 10:20 AM KENT BRITAIN <<a shape="rect" href="mailto:wa5vjb@flash.net" rel="nofollow" target="_blank">wa5vjb@flash.net</a>> wrote:<br clear="none"></div><blockquote class="ydpd08fb6b4yiv6188454366gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex;"><div><div><div></div>
<div dir="ltr">The typical Direct TV style dish looks at 1/4000 th of the sky.</div><div dir="ltr">Well, we only see 1/2 of the sky at any given time, so even if both birds are visible</div><div dir="ltr">at the same time, only 1/2000 of the time would they both be in the same beam</div><div dir="ltr">even if on the same frequency.</div><div dir="ltr"><br clear="none"></div><div dir="ltr">Yea, can crunch these numbers several ways but with a little frequency management</div><div dir="ltr">interference is going to be pretty rare. Kent WA5VJB<br clear="none"></div><div><br clear="none"></div><div><br clear="none"></div><div><br clear="none"></div><div><br clear="none"></div>
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On Friday, February 14, 2020, 12:03:12 PM CST, Michelle Thompson via Ground-Station <ground-station@lists.openresearch.institute> wrote:
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<div><div id="ydpd08fb6b4yiv6188454366gmail-m_-5241446838015378738ydp20b95d1cyiv7388914926"><div dir="ltr">With AREx and Lunar Orbiting Platform Gateway (usually just called "Gateway") developing and progressing, Paul KB5MU brought up something we need to check on.<br clear="none"><br clear="none">If Gateway uses the 10GHz amateur downlink (and they plan to) how much impact do other 10GHz payloads present? QO-100, Phase 4X, CatSat, etc.?<br clear="none"><br clear="none">I think any interference or outages are going to be very small, but I'd like to have an answer before someone like ARISS asks. <br clear="none"><br clear="none">If we all use DVB-S2/X, then it would seem that there would be a potential for brief interference. <br clear="none"><br clear="none">Assuming 10GHz downlinks from Gateway<br clear="none">1) how often would potential interference occur for GEO, HEO, LEO? <br clear="none">2) is there anything that we (or Gateway) should do about it? <br clear="none">3) is there anything that we (or Gateway) could do about it?<br clear="none"><br clear="none">Goal: Quantify and document. <br clear="none"><br clear="all"><div><div dir="ltr"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr">-Michelle W5NYV<br clear="none"><br clear="none"><div dir="ltr"><br clear="none"></div></div></div></div></div></div></div></div></div></div></div></div>
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