Abstract: The test range is provided with a calibration system for calibrating the exact position of a light curtain formed by a ballistic screen. The calibration system uses a model ball which can be moved through a light screen at high speed in order to simulate the actual passage of a driven golf ball through the light screen. Positioning of the model golf ball at a point at which the golf ball just contacts the light screen serves to determine the exact location of the light screen. A laser ranging device is used to locate the calibration system relative to a launch point. Thus, the precise distance of the curtain of light from the launch point can be readily determined. The calibration system may also be used to determine if a ballistic screen is mounted in a true vertical plane.

Abstract: The system for determining the carry and/or lateral deviation and/or flight time of a driven golf ball uses a grid of geophones to sense the time of impact of a driven golf ball. The geophones are buried in the ground so that the impact is sensed via sound waves travelling through the ground. A computer receives a signal from each sensor indicating an impact and determines the time at which the impact was sensed by each sensor and screens out all but the six shortest times of impact. This information is then used to mathematically calculate the point of impact within a square of geophones corresponding to the recorded times. A plot of the flight path of the golf ball can be displayed on a display monitor based upon the carry and the flight time. The calculated flight time and carry are compared with a known standard to determine conformance with the standard.