Quantifying Retroreflective Materials using Digital Imagery JS Forensic Consulting, LLC

Format:

Book

Conference/Event

Author/Creator:

Suway, Jeffrey, author.

Contributor:

Cornetto, Anthony

Conference Name:

WCX SAE World Congress Experience (2020-04-21 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2020

Summary:

Retroreflection occurs when a light ray incident on a surface is reflected back towards the light source. The performance of a retroreflective material is of interest to accident reconstructionist, human factors professionals, lighting professionals, and roadway design professionals. The retroreflective effect of a material can be defined by the coefficient of retroreflection, which is a function of the light's entrance angle and the viewer's observation angle. The coefficient of retroreflection of a material is typically measured in a laboratory environment or in the field with a retroreflectometer. Often the material in question cannot be taken to a laboratory for testing and commercially available portable retroreflectometers are limited to entrance angles of 45 degrees or less and may be cost prohibitive in some cases. This paper presents a methodology to capture images of a retroreflective material at entrance angles between -90 degrees and 90 degrees and observations angles between 0.2 degrees and 1.2 degrees. The process of calibrating the camera and the light source is presented and the coefficient of retroreflection is calculated from the images and presented as a function of entrance angle and observation angle

Notes:

Vendor supplied data

Publisher Number:

2020-01-0570

Access Restriction:

Restricted for use by site license