气泡激光散射信号处理方法

Processing Methods for Laser Scattering Signals of Bubbles

提出了阈值检测、降噪处理和功率谱估计三种分析和处理水中气泡激光散射信号的方法。利用这三种方法分别对不同散射角时的测量信号进行了处理.得到了水中气泡激光散射强度随散射角的分布特性,并将实验结果与米氏(Mie)理论结果及水的散射强度进行了对比,比较和分析了三种方法的优劣。阈值检测法和降噪处理法分别以平均值和绝对偏差为中心来估计气泡散射强度,它们不能隔离直流分量。功率谱估计法处理得到的气泡角散射特性与Mie理论结果一致,能够区别开气泡散射和水的散射,两者相差近1个数量级。实验结果表明功率谱估计法是最合理的处理气泡激光散射信号的方法。

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.