MIE散射系数的改进算法

提出一种新的计算MIE散射系数的算法。该算法使用了改进的后向递推公式,可对MIE系数中的消光系数Kext和散射系数Ksca进行精确计算。由于新算法能显著地减少计算循环次数,因此明显缩短了计算时间。对广泛运用的递推法和连分式法进行了比较详细的讨论。并且把新算法的计算结果和已有的成果进行了比较。结果表明:(1)计算的循环次数与粒子的复折射率基本没有关系;(2)连分式得到的结果通常最准确;(3)新算法在尺度系数较大时(>1000),计算时间仅为连分式算法的10-2~10-3,计算的误差小于10-5;(4)算法的适用范围广,对于尺度系数从10-6到106,复折射率从从10-6到106都能很好地进行计算。

Improved algorithm for MIE scattering coefficient

A new improved algorithm for calculating MIE scattering coefficient is presented in the paper. This algorithm can accurately calculate extinction coefficient Kext and scattering coefficient methods Ksca. It base on improved backward recursion method and remarkably reduce the calculation time. The usually used methods, such as recursion method and continued fractions method, are discussed in detail. By comparison with calculation results of several algorithms, some conclusions can be obtained: (1) The cycle numbers is almost irrelevant to complex refractive index. (2) The continued fractions method usually can get the most accurate result.(3) Time consumed by new algorithms is 10-2~10-3 to continue fractions, and the error is less than10-5. (4) The algorithm is suit for size parameters from 10-6 to 106 and complex refractive index from 10-6 to 106.