Proceedings Article | 27 January 2009
KEYWORDS: Particles, Light scattering, Particle sizing, Dynamic light scattering, Particle sizing techniques, Chemical elements, Stochastic processes, Signal processing, Interference (communication), Particle systems
In photon correlation spectroscopy (PCS) particle sizing techniques, the choice of regularization parameter in the inverse
algorithm of Tikhonov Regularization can be classified into prior and posterior strategies. For prior strategies, the choice
of regularization parameter is made before calculating the regularized solution, but the posterior strategies, based on
some principles, make the choice of regularization parameter matching the error level of original data during the
calculation for the regularized solution. The critical issue of regularization method lies in the proper balance and tradeoff
between the accuracy and stability of the solutions, in other words, the regularization parameter chosen should match the
error lever of autocorrelation function. Using prior and posterior strategies, scattered light signal of 50nm, 100nm and
300 nm particles were simulated and their autocorrelation functions inversed respectively. If noise existed, the stability
was weakened while the deviation of peak value increased. For prior strategy, the noise influence to the inverse is
obvious when noise factor is 0, 0.01, 0.02, 0.04, 0.05, 0.06, 0.08, 0.1 and 1, but inverse results can be obtained on large
noise level even the noise factor is at 1. However, when using posterior strategy, the effect on inverse result was less
when error was small, but convergent inverse results cannot be obtained when the noise level is high.