Abstract: A measurement system obtains and stores digital data on the positions of golf club and significant human body parts during a golf club swing. An interactive display allows later display of the measured performance for use in instruction or review. A coordinate transformer allows the viewing of a displayed simulated golfer from any aspect and at variable speeds and stop action. A generator such as an alphanumeric or graphic generator displays suggested display options, graphics, informative labels, and alphanumeric tabular data. Permanent copies of any displayed picture can be made for later home study.

Abstract: Electro-optical sensors measure the location of a plurality of spots on the surface of a golf club head or a golf ball at a minimum of two precisely spaced points in time. The two time points for the club head are just prior to impact with the golf ball. The two time points for the golf ball are just after impact by the club head. From the apparent displacements of the plurality of spots between measurements, the apparatus determines in substantially real time the velocity of the club head or ball and the spin about orthogonal axes.