Naval Computer and Telecommunications Area Master Station, Pacific (NCTAMS PAC), Wahiawa, HI

Today, NCTAMS PAC is the center of communications for the U.S. Navy in the Pacific. As the largest communications station in the world, our mission is to provide communications for command and control to all naval commands ashore and afloat in the Pacific area and to a wide variety of Army, Marine Corps, Coast Guard and Air Force commands. 
 
 

http://www.nbvc.navy.mil/navsoc/history.html

Naval Security Group Activity Wahiawa. The big circle was an FRD-10 high-frequency direction-finding array. Sixteen were built at various sites around the world (full list in this thread). Only the two sites in Canada are still operational.

The Wahiawa site served as net control station for the Pacific HF-DF net. Although the array is being or has already been removed, the site will remain in the SIGINT business. The Hawaii Regional Security Operations Center is due to be built there in the next year or two, replacing the nearby Kunia RSOC, which is housed in an underground building dating back to World War Two. - Bill Robinson 

ANAVASTROGRU Det 'C'
By bhurlburt

Former location for the Navy Astronautics Group (NAVASTROGRU) Detachment C facility which included a building with a roof mounted antenna. Today both the site and the command have changed to better reflect the nature of its mission. NAVASTROGRU is now Naval Satellite Operations Center, still headquartered at Point Mugu, and Detachment C is locatied in Guam. Although the building is probably long forgotten its legacy continues in the name of the road, Polaris, showing the close relationship between NAVASTROGRU and the Polaris/Poseidon/Trident missle submarine program which was its most crucial user. 

NAVASTROGRU Det 'C' Oahu Hawaii
 

Schofield Barracks is a United States Army installation (and census-designated place or CDP) located in the City and County of Honolulu and in the Wahiawa District of the island of O`ahu, Hawai`i. Schofield Barracks lies adjacent to the town of Wahiaw?, separated from most of it by Lake Wilson (also known as Wahiaw? Reservoir). Schofield Barracks is named after Lieutenant General John McAllister Schofield. He was sent to Hawai`i in 1872 as Secretary of War for President of the United States Andrew Johnson and recommended the establishment of a naval base at Pearl Harbor.

Schofield Barracks occupies some 17725 acre on Central O`ahu. The base was established in 1908 to provide mobile defense of Pearl Harbor and the entire island. It has been the home of the 25th Infantry Division, known as the Tropic Lightning Division, since 1941. As of the 2000 Census, the base population was 14,428 military personnel and families.

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