WAVELET DE-NOISING OF TERRESTRIAL LASER SCANNER DATA FOR THE CHARACTERIZATION OF ROCK SURFACE ROUGHNESS

Abstract

The application of terrestrial laser scanning to the study of rock surface roughness faces a major challenge: the inherent range imprecision makes the extraction of roughness parameters difficult. In practice, when roughness is in millimeter scale it is often lost in the range measurement noise. The parameters extracted from the data, therefore, reflect noise rather than the actual roughness of the surface. In this paper we investigate the role of wavelet de-noising methods in the reliable characterization of roughness using laser range data. The application of several wavelet decomposition and thresholding methods are demonstrated, and the performances of these methods in estimating roughne..