Wavelet Noise Reduction in Dynamic Light Scattering

Abstract

Particle size determination with dynamic light scattering (DLS) is limited by noise. We have used a wavelet transform method to reduce noise in the DLS data. A digital storage oscilloscope (DSO) was used to capture the time-history of the scattered light intensity and signal denoising was implemented with a multi-scale packet wavelet transform. The experimental results indicate that, for a threshold of 0, corresponding to no denoising, the DLS signal with noise, does not give good results because the number of samples used to compute the correlation function was only 20k or 10k and the data are noisy. However, denoising with thresholds in the range 0.5-0.8 can give both better particle size values and smaller root mean square error from the same raw light scattering data.