Originally posted by Golf66
That is an antenna array. Like the ones you mentioned elsewhere. If you line up the locations you'll see there is one to "listen" to all of our areas of interest. Asia, Middle East, SE Asia, The South Pacific, Russia etc.
That one probably focuses on Cuba and the Caribbean area as well as some of South America.
They are at locations around the world and are used for radio intercept (SIGINT) and radio direction finding (RDF). They can be directed from various field stations across the world to intercept radio signals for the purpose of collecting intelligence on our enemies. NSA.
The antennas are not classified as they are there for all to see but their capabilities are.
The FRD-10's are pretty much all gone now. I think the Canadians are the only one's to have them now at two of their sites. But i could be wrong.
The one in San Diego is still there but the buildings are abandoned. I helped close it down.