Under the universal classification system for electronic radar and tracking systems, the letters “AN” (for Army-Navy) are placed ahead of a three-letter code. The first letter of the three-letter code denotes the type of platform hosting the electronic device, where A=Aircraft; F=Fixed (land-based); S=Ship-mounted; T=Ground transportable. The second letter indicates the type of device, where P=Radar (pulsed); Q=Sonar; R=Radio. The third letter indicates the function of the radar system device, where G=Fire control; R=Receiving; S=Search; T=Transmitting. Thus, the AN/FPS-115 represents the 115th design of an Army-Navy “Fixed, Radar, Search” electronic device. Elkins was part of a team of
Rome Air Development Center (RADC) engineers that developed and constructed components for
frequency modulation/
continuous wave (FM/CW) radars capable of detecting and tracking objects at over-the-horizon ranges. A prototype radar was installed and evaluated on 15 September 1970. The system incorporated a
Beverage array receiving antenna located at
Columbia Falls Air Force Station, a high-power transmitter array located at
Moscow Air Force Station, and an operations center located at
Bangor International Airport. This prototype became operational on 30 October of that year. Experimental transmissions from the Maine site covered a 60° sector from 16.5° to 76.5°
azimuth and from 900 to 3,300 km in range from the radar. Based on the success of these early experiments, the
United States Department of Defense proposed to deploy a fully operational radar system. This radar system, covering 180° in azimuth, was built at the same locations in Maine. Initial testing was conducted from June 1980 to June 1981.
GE Aerospace (now Lockheed Martin Ocean, Radar and Sensor Systems) received a contract in mid-1982 for full-scale development of the AN/FPS-118 program. The operational system consisted of multiple
OTH-B radars functioning as an
early warning system to detect incoming enemy bombers,
ICBMs, and
cruise missiles. The system, as initially envisioned, was to consist of four sectors: • East Coast Sector (ECRS): facing east, including a group of three transmitters at Moscow Air Force Station, a group of three receivers at Columbia Falls Air Force Station, also in Maine, and an operations center located at Bangor International Airport. • West Coast Sector (WCRS): facing west, including a group of three transmitters at
Christmas Valley, Oregon, a group of three receivers at
Tule Lake, near
Alturas, California, and an operations center at
Mountain Home Air Force Base in
Idaho. • North Sector (in
Alaska): facing north, cancelled prior to completion • Central Sector (in
Texas): facing south Only months after the system became fully operational, the
Cold War came to an end. The military requirement for the OTH-B radar network was therefore greatly diminished. The mission of the ECRS radar system was redirected to counter-narcotics surveillance and
drug interdiction, and the ECRS operated in this capacity for several years. The three OTH radars of the WCRS were mothballed, and the incomplete North Sector in Alaska was cancelled. The Air Force currently maintains the six East Coast and West Coast OTH-B radars in a state called
warm storage, which preserves the physical and electrical integrity of the system and permits recall, should a need arise. It would require at least 24 months to bring these first-generation OTH-B radars into operational status. ==Later career==