Radar Processing Center (RPC) of the AN/MSG-4 Missile Monitor. The basic system consists of four major components—the Army Air Defense Command Post (AADCP), frequency scan radar, operations center, and coder-decoder group.
U.S. Dept of the Army
<a rel="nofollow" class="external text" href="http://sill-www.army.mil/firesbulletin/archives/1960/MAY_1960/MAY_1960_FULL_EDITION.pdf"><i>Artillery Trends</i></a> May 1960, Page 45, Figure 27.