Comparison of Surface Roughness Measurement in Dichromatic Speckle Patterns with Autocorrelation Method
Applying autocorrelation method to process laser speckle patterns, the relation between surface roughness and speckle elongation and correlation length of autocorrelation function can be obtained, and the measured surface roughness can be achieved based on this relation. One-dimension autocorrelation and two-dimension autocorrelation function are used, Moreover, surface roughness is evaluated by speckle elongation and correlation length of autocorrelation function. Aspect ratio of speckle granular represents speckle elongation ratio, which eliminates effects of speckle granular average size on measurement results compared to other methods using before. It has high reliability and efficiency in surface roughness measurement evaluation.
Zhengyi Jiang, Shanqing Li, Jianmin Zeng, Xiaoping Liao and Daoguo Yang
Z. H. Yuan et al., "Comparison of Surface Roughness Measurement in Dichromatic Speckle Patterns with Autocorrelation Method", Advanced Materials Research, Vols. 189-193, pp. 680-683, 2011