Originally Posted by
pasta
As an indication of ship-borne capabilities, the Astute class sonar is claimed to have a range of 3000 miles (whatever that means in practice). SOSUS, or whatever's succeeded it, is presumably more capable. There's also satellite imaging (this is a surface vessel), ELINT, and plain old radar. I'd be amazed if tracking vessels such as this were even vaguely challenging or anything other than routine.
Surely passive sonar will give you a bearing but not a range unless different sensors are combined (unless the SM is close enough to be in trail). Satellite imagery is intermittent, the claim was that the
precise whereabouts was known at all times. Likewise, I would have thought ELINT and radar woud require a shadow vessel to provide reliable data.