Does anyone have a clue what this naval defense system might be?

I would hesitate to post this except that it can be found on the exterior of the ship so it can’t be that unknown. It can be found on one of the higher decks of the USS Ashland. The guy giving the tour said it was some kind of missile defense system. He gave some kind of technical acronym of a name but I don’t remember what it was. Anyway I’m interested in learning how the system works. I would guess it puts out flares or maybe even an intercepting missile but I haven’t been able to find it or much like it in naval missile defense. Could this be a part of the Aegis program?

Photo: http://goo.gl/iiXi3