[bell-cot]

It was a huge surface ship, at sea. It was probably spotted in a 20 or more different ways - from commercial satellite imagery to HUMINT to its own radar transmitters to Russian sailors' cell phone signals.

Every way of spotting a target suffers from uncertainty. Most suffer from delays (satellite photo is X hours old), security issues (keep your spies alive), and political considerations (Ukrainians might want to feel that they are fighting and winning, not just acting as push-button-when-told minions of foreign powers).

Waiting to attack it until that could reliably be done with all-Ukrainian assets, all of which the Russians already knew about - that maximizes the number of checked boxes, eh?

[ethbr1]

The initial reporting after was that:

   - Ukraine performed the initial radar detection
   - Ukraine asked the US to confirm it was the Moskva (the US did)
   - Ukraine attacked with their own targeting data

(Then news articles clammed up about the US confirmation, and the Pentagon put out some carefully worded statements that tried to establish distance)

Which sounds reasonable. Warships like the Moskva are strategic assets.

That lowers the bar for acceptable amount of help from the US before Russia escalates.

[bell-cot]

That sounds like a plausible sequence of moves. And the initial over-sharing of a "get US confirmation" step might serve some Ukrainian strategic goals, too...

[hulitu]

> Ukraine performed the initial radar detection

> Which sounds reasonable

If you don't know anything about radars, yes.