On Fri, Jul 2, 2021 at 15:51 Ronald F. Guilmette <[email protected]> wrote:
> In message <[email protected]>, > Paul Wilson <[email protected]> wrote: > > >Hi Ronald, a very late reply here? > > > >The Starlink dishes are very much steerable - as you see here: > > > > https://www.youtube.com/watch?v=yNeVTMJvqFQ&t=478s > > Thank you for this Paul! > > It explains some things about how this all works, but not others. > > Is the dish actually going to -track- the specific satellite that > your ground station is currently talking to? > > And if so, what happens when that satellite sets below the horizon? > > Obviously, this will imply a disconnect and a loss of signal for > some period of time until your dish gets re-aimed at some different > satellite, but how long does THAT take? > Dishy, as they call the dish, is a self pointing phased array antenna, it primarily tracks the satellites electronically, through phased array beam forming. The mechanical system simply points the antenna to the right part of the sky to track the sequence of satellites. Therefore, the tracking of the next satellite in the sequence is almost instantaneous. I believe during the beta, because the complete constellation of satellites isn’t available yet sometimes Dishy has to reposition, causing short broadband outages. However, as the constellation of satellites get more and more complete this should happen much less often. And when the constellation of satellites is complete repositioning should happen rarely. See the following; https://en.m.wikipedia.org/wiki/Phased_array And at this link they tear Dishy apart; https://hackaday.com/2020/11/25/literally-tearing-apart-a-spacex-starlink-antenna/ The US Navy’s Aegis Combat System was one of the first large scale uses of Phased Array technology and was developed in the ‘70s and deployed in the ‘80s. So the technology has been around for a while. https://en.m.wikipedia.org/wiki/Aegis_Combat_System WiFi 5, 802.11ac, also includes beam forming technology, a much more simplistic version, as WiFi systems usually don’t have more than a handful of antenna elements. Where Dishy appears to have couple hundred antenna elements. https://www.networkworld.com/article/3445039/beamforming-explained-how-it-makes-wireless-communication-faster.amp.html Hope that helps. -- =============================================== David Farmer Email:[email protected] Networking & Telecommunication Services Office of Information Technology University of Minnesota 2218 University Ave SE Phone: 612-626-0815 Minneapolis, MN 55414-3029 Cell: 612-812-9952 ===============================================
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