摘要 |
<p>An apparatus for measuring surface properties of a carriageway or road, comprising a platform arranged to move over the carriageway, the platform carrying a light source arranged to illuminate the carriageway, and a detector arranged to receive light returning from the carriageway, characterised in that the light source projects a line of light onto the surface, the line of light being parallel to the direction of travel, and data representing light returning from the line of light is captured and stored. The displacement of the vehicle between two successive measurements is estimated from the cross-correlation of the two successively measured profiles.</p> |