| 摘要 |
<p>Method and apparatus for determining the position at which a projectile passes through an area in space. Two light beams are projected to scan the whole of the area in space, and detector means are provided for detecting the reflections of said beams off a projectile passing through said area. Means are provided for determining the angular relationship of the reflected beams relative to established reference lines at spaced reference points to accurately determine the position at which the projectile passes such area in space.</p> |
