Hello I watched some of the US Open 2011 matches. E.g. in this one: http://www.youtube.com/watch?v=HX9eAgni8cE there is a person sitting beside the court shooting the course of the ball with some kind of long black stick. I haven't seen this in other grand slams. For what purpose is that shooting? Is it a directional microphone used to enhance voices from the racket hitting the ball? If it's for that, it looks a bit low tech means for that. Anyone able to advise me?