Secondly, the number of satellites doesn’t really matter, the jamming happens at the end user level not at the satellite.
Finally, where are you getting that 20k number from? It’s not like there’s 20k starlink satellites in LOS to your station at all times. The earth will be obscuring many of those, they are below your feet on the other side of the planet.
I was under the impression that Starlink needs GPS for initial acquisition.
gps is 31 total satellites 12,000 miles up
starlink is 10,000 satellites at ~ 300 miles. (and what orbit?)
EDIT: I found this:
-- starlink:
"In any given place there are 3-4 Starlink satellites visible at a time"
https://news.ycombinator.com/item?id=42445512 :)
in december 2024, there were 4,000 starlink satellites in orbit
so starlink is ~ 8 at all times?
-- GPS:
This 24-slot arrangement ensures users can view at least four satellites from virtually any point on the planet.
Our RTK base station (a Ublox ZED-F9P receiver, with a cheap patch antenna on the roof) can currently see 45 GNSS satellites.