Patent ID: 7995796

Claim:
A method for determining sheeting type of a reflective sheeting material covering a road sign comprising: means for illuminating at least a portion of the reflective sheeting material covering the road sign from a plurality of distances along the roadway; means for collecting a plurality of light intensity measurements reflected from the at least a portion of the reflective sheeting material; means for generating an as-measured retroreflectivity profile using the light intensity measurements corresponding to exemplary angular displacements of incident light from a reference position; means for providing a database of retroreflectivity profiles with each retroreflectivity profile having an associated known sheeting type; means for comparing the as-measured profile to each retroreflectivity profile from the database of retroreflectivity profiles; means for selecting the retroreflectivity profile that best correlates to the as-measured retroreflectivity profile; and means for determining sheeting type of the reflective sheeting material based on the known sheeting type associated with the selected retroreflectivity profile.