两点标定法求解背景气溶胶S_a(z)值的可行性研究

Feasibility Study for Acquiring S_a(z) Value of Background Aerosol Using Two-Point Calibration Method

对两点标定法求解气溶胶消光后向散射比Sa(z)的可行性进行了研究。讨论了利用两点标定法反演气溶胶消光后向散射比的精度和两标定点之间距离的关系:当两点之间的距离大于1km时,利用两点标定法得到的气溶胶消光后向散射比是可靠的。对比分析了两标定点间的距离大小及两种不同的迭代方法对两标定点之间气溶胶消光后向散射比反演结果的影响。并对两点标定法用于气溶胶消光后向散射比反演时,预先对反演结果进行误差估计的可行性进行了探讨。实际反演结果表明,利用两点标定法进行气溶胶消光后向散射比的反演,当两标定点之间的距离大于1km且标定点的气溶胶消光系数的误差为5%时,反演得到两标定点之间气溶胶消光后向散射比的误差一般不会超过6%。

Feasibility of using two-point calibration method to acquire aerosol extinction-to-backscattering ratio is explored. Two-point calibration method is one of the important methods for acquiring aerosol extinction-to- backscattering ratio. The relationship between the distance of the two calibration points and the accuracy of aerosol extinction-to-backscattering ratio acquired by using two-point calibration method is discussed. The aerosol extinction- to-backscattering ratio obtained by using two-point calibration method is reliable when the distance between the two points is greater than 1 km. The influence of the distance between the two calibration points on the inversion results of aerosol extinction-to-backscattering ratio from one calibration point to another one is analyzed. The influence to aerosol extinction-to-backscattering ratio inversion results of two different iterative methods is discussed. The feasibility of beforehand error estimation of inversion results when two-point calibration method is used for the inversion of aerosol extinction-to-backscattering ratio is investigated. The inversion results show that the error of aerosol extinction-to-backscattering ratio between the two calibration points does not exceed 6 % generally when the distance between the two calibration points is greater than 1 km and the extinction coefficient error of the calibration point is 5 %.