Yes, the dome houses the radar and fire control system.

I've been told that it works so well because the radar tracks not only the target but also the bullets in flight to said target. This makes fire control a lot easier and more accurate. All the system has to do is maneuver to bring the two radar images into coincidence. That's much easier than trying to predict the flight of the target and generate the required "lead" for firing a projectile sitting in the chamber.