Hey, today while watching the cricket I was fascinated by "Hawkeye" and how it predicted the ball trajectory, from the bowlers hand to a few metres past the batsmen. "Hawk-Eye is a computer system used in cricket, tennis and other sports to track the path of the ball." http://en.wikipedia.org/wiki/Hawk-Eye Now I've looked around the net, to find some explanation of how it works, but have failed. I can only think of two things that it would rely on, either there are many cameras that follow the ball, and then create a model for the trajectory, or there is some equations(s) that are used aswell. Does anybody have any knowledge of this subject, or possibly an explanation of how it works? What type of equations would you use to calculate the trajectory? I am an AS Student studying physics so my knowledge on equations of motion is fairly limited. Though this thread is specifically about cricket ball trajectory, I would also be interested in the ball trajectory of other sports such as golf or even tennis. Thanks. :shy: EDIT: I changed the first post, because the original post was poorly written.