[Starlink] Starlink "beam spread"

[David Lang]

On Wed, 31 Aug 2022, Ulrich Speidel via Starlink wrote:

> This combines with the uncomfortable truth 
> that an RF "beam" from a satellite isn't as selective as a laser beam, 
> so the options for frequency re-use from orbit aren't anywhere near as 
> good as from a mobile base station across the road: Any beam pointed at 
> you can be heard for many miles around and therefore no other user can 
> re-use that frequency (with the same burst slot etc.).

not quite, you are forgetting that the antennas on the ground are also steerable 
arrays and so they can focus their 'receiving beam' at different satellites. 
This is less efficient than a transmitting beam as the satellites you aren't 
'pointed' at will increase your noise floor, but it does allow the same 
frequency to be used for multiple satellites into the same area at the same 
time.

David Lang