Accession Number : ADD003223

Title :   Optical Method for Surface Texture Measurement.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Gee,Sherman

Report Date : 09 Sep 1975

Pagination or Media Count : 5

Abstract : This invention relates generally to the measurement of surface texture (roughness) and more particularly for the measurement of highway pavement surface textural characteristics. The surface qualities of a highway pavement determines to a large degree the conditions under which safe driving can be maintained. The ultimate objective is to employ pavement material which will reduce the frequency and severity of highway accidents due to skidding and loss of control of the vehicle under various driving conditions. The invention provides a system to measure the polarization characteristics of light reflected from the pavement surface. By illuminating the road surface with linearly polarized light such as from a laser source mounted on a moving vehicle, the reflected light will become depolarized as a result of diffuse scattering from the textured road surface. The reflected light will generally be elliptically polarized, the degree of ellipticity being dependent on the pavement textural characteristics.

Descriptors :   *Patents, *Pavements, *Surface roughness, *Test equipment, Optical instruments, Measuring instruments, Texture, Highways, Light, Polarization, Instrumentation, Laser beams

Subject Categories : Civil Engineering
      Test Facilities, Equipment and Methods
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE