PROJECTILE-IMPACT-LOCATION DETERMINATION - AN ACOUSTIC TRIANGULATION METHOD

A unique method of determining the impact position of a projectile has been developed which is based on the measurement of acoustic waves ge nerated by the impact of the projectile on a target screen and incorpo rates three microphones positioned at the screen corners. By detecting and measuring the differences in arrival times of the airborne sound wave at three points, the impact location can be found. A closed form solution to the nonlinear equations expressing the impact location in terms of the differences in arrival times of the sound waves has been found. The technique has been applied to golf balls striking a screen of dimensions 2.5 m by 3.0 m, with an accuracy of position measurement of +/-0.05 m. The system has been demonstrated over a wide range of p rojectile velocities from as little as 3 m s(-1) up to speeds of over 50 m s(-1).