Your calculations are “Back of the Envelope Approved” :-) 

My simulator can be found at https://starlink.sx and runs on your browser (desktop only). I have just released v1.10.6, which adds a slider for setting the GSO protection. This is the difference in Sweden from 18º (as used until recently) versus 10º (as found in recent ITU filings for STEAM-1B):



Minimum elevation in both cases is 25º, so that variable is unchanged.

Best,

Mike
On Jul 25, 2022, 11:35 +0300, Ulrich Speidel via Starlink <starlink@lists.bufferbloat.net>, wrote:

I haven't got Mike's nice software but I got snail mail today, so let's try the back of one of the envelopes.

53 degrees north (where the existing constellation tops out) is roughly the latitude of Nottingham or Stoke-on-Trent. Note that this is also the latitude with the largest number of birds per km (or mile, if you so prefer) of parallel. They sit almost cheek to jowl there.

Now the northern tip of the UK's main islands is at around 59 degrees north - that's six degrees more. One degree of latitude is roughly equivalent to 10,000 km / 90 degrees = 111 km, so we're talking around a devilish 666 km to the north of Nottingham here as the crow flies.

Lets assume Dishy points itself due south at 59 degrees. The birds are at about 550 km. So doing a flat earth approximation for the moment, we're having to point at a satellite 550 km up from 660 km away - that gives an elevation of about 40 degrees (=arctan(550/660)). Ballpark. Now reduce that by the 6 degrees of difference to account for the curvature of the earth and we still have around 34 degrees, allowing for a bit of leeway either side if the closest bird isn't actually due south but a bit to the east or west. Again, ballpark, but we're nowhere near 25 degrees yet.

So I'd say that should cover it nicely? Where does my envelope err? GEO arc protection aside for the moment, of course. And of course just because Starlink offers you service doesn't mean that it's actually continuous.

On 25/07/2022 8:59 am, Dave Taht via Starlink wrote:
For those of you that don't follow mike's twitter feed...

https://twitter.com/mikepuchol/status/1551288485713149952

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FQ World Domination pending: https://blog.cerowrt.org/post/state_of_fq_codel/
Dave Täht CEO, TekLibre, LLC
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Dr. Ulrich Speidel

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