Evaluation of Doppler Radar Ball Tracking and Its Experimental Uses by Jason

by JASON JOHN MARTIN, M.S. Washington State University December 2012 Chair: Lloyd V. Smith Doppler radar is being implemented in baseball and softball venues around the world to track the trajectory of pitched and hit balls. The units are positioned behind home plate and can track the pitch and hit speeds, spin rates, angles, and ball positions. The data is used to measure the performance of players, as well as keep statistics on the game. The radar units are also used by sporting goods manufacturers to measure the performance of equipment. The goal of this study was to determine the accuracy of data reported by the radar. When compared to high speed video, the radar measured the speeds of the hit and pitch near home plate to within 2.8%, and 2.3% respectively. The associated angles were within 1.2°. Hit distances of the radar were within 5% of a laser range finder. The hit and pitch speeds and angles near home plate were within 0.2% and 0.6°, respectively when compared to infrared video tracking. Balls hit at increasing horizontal angles experienced increasing radar noise and an optimal vertical angle of 15° minimized noise. An error of 4 m (13.1 ft) in the initial ball position resulted in an error of the velocity and angles of a pitch of 4 m/s (8.9 mph) and 8°. An analysis of game and field study data provided a measure of the vertical and horizontal release point of the pitch. When the starting point of the pitch was held constant, a standard deviation of 0.03 m (0.09 ft) and 0.04 m (0.13 ft) in the horizontal and vertical position