I think you meant to say Phalanx gun. (or however you spell phalanx...) aegis is the radar system that several ships (ticonderoga and arleigh burke classes) use.
If i had to guess, yes...it sounds very much like the phalanx, radar controled...i just cant figure out the projectile. From the video, the head of the RPG is sheered off clean. Who knows.
oh and edit:
http://biz.yahoo.com/prnews/060330/dcth048.html?.v=44 so it is a real thing.