【摘要】 初步反演结果表明,Fernald前向积分法(FFIM)能够用于机载大气探测激光雷达气溶胶后向散射系数的反演,但相应的理论解释没见国内外相关文献报道.根据合肥地基大气探测激光雷达2008年2月27日的探测数据模拟得到的机载激光雷达数据,对FFIE用于机载大气探测激光雷达气溶胶后向散射系数的反演结果进行了定量分析,分析表明:当反演标定点的高度选在10km左右时,FFIM能够用于机载大气探测激光雷达气溶胶后向散射系数反演的主要原因有3个:1)Fernald前向积分方程(FFIE)分母中两项的差值一般远大于零,这决定了FFIM应用于机载大气探测激光雷达气溶胶后向散射系数反演时,反演误差不会无限大而且反演结果不会出现负值;2)标定值误差为100%时,在整个反演过程中误差项的值仅变化了0.006,是标定值没有误差时分母值的0.6%;3)FFIE的标定项中分子的后向散射系数占主导地位,标定点的气溶胶后向散射系数变化较大的值,对整个标定项的值影响却很小.研究表明,上疏下密的大气结构和较高的标定位置是FFIM能够用于机载大气探测激光雷达气溶胶后向散射系数反演的根本原因.更多还原

【Abstract】 Preliminary inversion results show that the Fernald forward integration method(FFIM) can be used to calculate aerosol backscatter coefficient from airborne atmosphere detecting lidar.But the corresponding theoretical explanations have not been found in relevant papers.In this paper,We use the simulated data based on the ground-based atmosphere detecting radar in Hefei lidar data on February 27,2008,to quantitatively analyze the above inversion results obtained by the FFIM.Results show that there are three main reasons that the FFIM can be used to calculate aerosol backscatter coefficient when the altitude of lidar calibration points is about 10km.First,the inversion error cannot be infinite and negative results will not appear because the difference batween the denominator items in the Fernald forward integration equation is always greater than zero.Second,inversion error is no more than 0.006 when calibration error is 100%,which is 0.6 percent of the denominator value.Third,Molecule backscatter coefficient is dominant in the calibration item of the Fernald forward integration equation.Big fluctuation range of aerosol backscatter coefficient in the calibration points has little influence on the calibration item value.In general,the atmosphere structure that has a small density in the upper layer but a big density in the lowerlayer,and a high calibration position are two basic reasons for which the FFIM can be applied to the aerosol backscatter coefficient inversion through using airborne atmosphere detecting lidar data.更多还原