PARCS

Perimeter Acquisition Radar Attack Characterization System, or PARCS was an American radar system located in North Dakota near Grand Forks.  It was part of the anti-ballistic missile system and consisted of one phased-array radar. 

PARCS was a back-up for BMEWS.  It especially looked for missiles and gave information about them during their flight.  It reached 2,800 kilometres and 130 degrees.