Big bro's reply.....
Translation: HFDF = High frequency direction finding - COMSTA = Communications Station = CT Communications Technician (Spook) - NavSecGru - Naval Security Group
"That's what was called Northwest Radio Station back in the old days... I think it was originally a Comsta. Somewhere along the way it became a spook HFDF site - that's the circle. It was a NavSecGru asset when I was at Dam Neck... one of the guys I worked with knew someone at Northwest (CT type) and used to be able hunt down there. No civilians and extremely restrictive for the military so they had deer running around in swarms...
Looking at the google shot, I'm not seeing a lot of antenna's in the HFDF circle... but it looks like the concrete bases are still there. I suspect most of the HF stuff is gone from military comms and secgru stuff - replaced by them there big dishes and cellular towers...
Pretty darn good resolution... didn't have overhead imagery near that good when I was chasing bad guys, much less in color...
Mikey"