Patent ID: 6895677
Filing Date: 2005-05-24
Classification: G01C

Abstract:
1. An apparatus for providing a temporary visible reference line across a surface, comprising: a first laser source disposed at a first elevated, stationary location relative to the surface, said first laser source being operative to emit optical energy at a wavelength of between 380 nm and 750 nm along a selectable path within a first region of the surface so as to form at least a portion of a temporary visible line thereon; and a second laser source disposed at a second elevated, stationary location relative to the surface, said second laser source being operative to emit optical energy at a wavelength of between 380 m and 750 m along a selectable path within a second region of the surface so as to form at least a portion of a temporary visible line thereon; and a controller, said controller being responsive to input user commands to operate said first laser source when a temporary visible line is to be formed within the first region and to operate said second laser source when a temporary visible line is to be formed within the second region of the surface.