Apparatus and method for measuring retroreflectivity of a surface

摘要

An apparatus for measuring the retroreflectivity of a surface. The apparatus comprises a light source for illuminating an area of said surface at an incident angle relative to the surface; a detector for detecting light reflected back from the surface at an observation angle relative to the surface; a signal processing unit adapted to receive a detector signal from the detector and to determine, from at least the received detector signal, a measure of retro reflectivity of the surface; a range finder for measuring a distance between the apparatus and the illuminated area. The signal processing unit is further adapted to adjust the measure of retroreflectivity responsive to the measured distance.

主权项

1. An apparatus for measuring retroreflectivity of a surface, the apparatus comprising:
a light source for illuminating an area of said surface at an incident angle relative to the surface; a detector for detecting light reflected back from an observation area of the surface at an observation angle relative to the surface; a signal processing unit adapted to receive a detector signal from the detector and to determine, from at least the received detector signal, a measure of the retroreflectivity of at least a part of the surface; at least one device for measuring a distance between the apparatus and the illuminated area, the device for measuring a distance between the apparatus and the illuminated area comprising the light source, the detector and the signal processing unit; wherein the signal processing unit is further adapted to adjust the measure of the retroreflectivity responsive to the measured distance; characterised in that the detector comprises a position-sensitive detector for detecting light as a function of a position within a light receiving area of the detector, wherein the signal processing unit is adapted to determine the distance from a position within the light receiving area of the detected light reflected back from the surface.