As far as I can see from open source material - no.
https://www.brookings.edu/opinions/t...clear-weapons/
There may be classified
MASINT techniques we are not aware of.
The warheads are around the size of a football.
Very easy to transport just one from the (presumably) known locations where they are stored.
You'd assume or at least hope that there'd then be some limited activation of Russian command and control infrastructure which western SIGINT would rapidly pick up.
It all seems very Tom Clancy, but also a real risk in my view that in the next 10 days or so, there will be more nuclear threats.