How Was China's Tiangong-1 Space Station Crash Tracked So Accurately?

How Was China's Tiangong-1 Space Station Crash Tracked So Accurately?  Space.com Tiangong-1, China's First Space Station, Crashes Into the Pacific  New York Times China's Tiangong-1 Space Station Crashes Back to Earth  Slate Magazine Malfunctioned Chinese Space Station Crashes Back To Earth  ValueWalk Chinese space station plunges into the ocean. No one hurt, no one there.  Washington PostFull coverage