Processing methods for laser scattering signals of bubbles

Three methods for analyzing and processing the laser scattering signal of bubbles in water, the threshold detection, noise elimination processing and power spectral estimation, are put forward. Using the above three methods, the measured signals for different scattering angles are processed respectively and the angular distribution of light intensity scattered by bubbles in water is obtained. Compared with Mie result and water scattering intensity, advantages of three methods are analyzed. The average value and the absolute deviation respectively are centered in the threshold detection and noise elimination method to estimate the bubble scattering intensity, and the DC component could not be isolated by them. The angular scattering property of bubbles obtained using the power spectral estimation agrees with the result based on Mie theory. Bubble and water scattering could be distinguished based on this method, and the difference of them would be nearly one order of magnitude. Experimental results show that the power spectral estimation is the most reasonable method for processing the laser scattering signal of bubbles.