I’m assuming they needed to have very accurate orbit information for each satellite. Was this provided to them by SpaceX, or was it derived from the signal?
IIRC the abstract says they just used semi-publicly available ephemerides that the Space Force publishes
Yeah, I think they said they used the TLEs. There are better ephemerides posted by SpaceX on space-track.org under contract w/ the govt, who doesn’t really want to be responsible for tracking all those objects.