 SAGE was a system of large computers and associated networking equipment that coordinated data from many radar sites and processed it to produce a single unified image of the airspace over a wide area.In 1953,at the same time that the USAF was developing SAGE, the Naval Research Laboratory showed Marine Corps representatives the findings of its Electronic Tactical Data Systems program to determine the services' interest in any further development.There was no money at the time however the Marine Corps continued to refine requirements for their future automated tactical data system for air defense operations.