An acoustic sensor system for determination of macroscopic surface roughness

In this paper, an alternative technique for the measurement of roughness of road surfaces is proposed. This noncontact method is based on the scattering of acoustic waves from the road surface and measuring the normalized Fourier spectrum of the scattered wave in the specular direction. Surfaces prepared with different size aggregates ranging from 2.36 mm to 25 mm were analyzed. The roughness parameter of a surface increases linearly with increasing aggregate size. The proposed method can possibly be extended to perform in situ surface roughness measurements from a moving vehicle.