"J. Severyn" wrote in
:

Periodic uploads of ephemeris and clock data to the SV, testing,
maintenance, switching of clocks, etc. from Master Control at
Schriever Air Force Base.

And tests of jamming equipment. The only way to be sure whether a system
can be jammed is by jamming it.

--
Regards,

Stan

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." B. Franklin