There have been similar claims regarding detecting stealth aircraft since about the day that the existence of the F-117 was officially announced. I specifically remember such claims regarding Russian systems back when USENET was a thing... I am only mildly surprised that they can look at the data in an area where they already know that an aircraft was located and say "See, there it is!" I would be shocked if they were able to actually track such an aircraft (or even a non-stealth aircraft) that they didn't know about in advance, or in anything resembling real time.
Mike
