The GE AN/GPA-73 Radar Course Directing Group (mobile version AN/CPA-73) was a US Cold War air defense command, control, and coordination system developed for the Electronic Systems Division 412L Air Weapons Control System (colloq. "AWCS 412L") for (ground-controlled interception, GCI, by "Fire Direction and Control Equipment"). The AN/GPA-73 was used to create a "Base Air Defense Ground Environment" (BADGE II), for which Air Defense Command had recommended the system as "SAGE back-up (Mode Ill) control of BOMARC" in June 1958. When the GPA-73 was emplaced with the AN/FSA-21 Weapons Control Group computer for GCI, the system created a "miniature SAGE" military installation. The GPA-73 could also direct Project Nike surface-to-air missile fire from Nike Integrated Fire Control sites equipp