US Patent 7292711 Flight parameter measurement system

A portable flight parameter measurement tracks the surface of an object in motion, e.g., a ball, and determines speed, trajectory, a spin axis, and a spin rate around that axis. The measurement system is particularly suited for analyzing the path of a ball in flight which is affected, in great part, by the amount of spin and the direction of spin imparted to the ball upon impact. The measurement system provides a user, such as a golfer, with important feedback for modifying his or her swing to obtain desired results. The measurement system utilizes non-precision marks, surface blemishes such as cuts made by a club, dimples, or a combination of all three as the only features necessary to determine ball flight characteristics.