摘要
分析了差分吸收光谱法反演大气二氧化氮(NO2)浓度过程中任意选择缓变吸收结构表达式对反演结果的影响。传统的二氧化氮浓度反演中直接用比值光谱的低阶拟合曲线代替缓变吸收信息,阶次选择任意,数值模拟发现这种方法会给反演结果带来很大的误差(最大在40%以上)。本文提出以二氧化氮吸收截面为参考,通过对比值光谱的非线性回归,确定缓变吸收信息的表达式。此方法避免了拟合多项式选择的任意性,提高了二氧化氮浓度反演的准确性,数值模拟结果误差不超过1%,并以此获得了合理的二氧化氮浓度实测值。
The influence of different slow - variation fitted curves on the retrieve of NOz density by DOAS is analyzed in this paper. It is discovered that random choice of the fitted curve may bring great error to the result, the greatest error exceed 40% to the numerical simulation. A new method searching for the slow - variation absorption structure through nonlinear regression is displayed, by which random choice of polynomial is avoided. By this method the precision of retrieved NO2 density is improved obviously. Finally, the real NO2 vertical column density (VCD) of Chengdu in May 15th,2006. is retrieved.
出处
《光散射学报》
2007年第1期70-73,共4页
The Journal of Light Scattering
基金
国家自然科学基金资助(编号:60478044)