Browell E V, Ismail S, Shipley S T
NASA Langley Research Center, Hampton, Virginia 2366, USA.
Appl Opt. 1985 Sep 1;24(17):2827-36. doi: 10.1364/ao.24.002827.
The differential absorption lidar (DIAL) technique generally assumes that atmospheric optical scattering is the same at the two laser wavelengths used in the DIAL measurement of a gas concentration profile. Errors can arise in this approach when the wavelengths are significantly separated, and there is a range dependence in the aerosol scattering distribution. This paper discusses the errors introduced by large DIAL wavelength separations and spatial inhomogeneity of aerosols in the atmosphere. A Bernoulli solution for determining the relative distribution of aerosol backscattering in the UV region is presented, and scattering ratio boundary values for these solutions are discussed. The results of this approach are used to derive a backscatter correction to the standard DIAL analysis method. It is shown that for the worst cases of severe range dependence in aerosol backscattering, the residual errors in the corrected DIAL O3 measurements were <10 ppbv for DIAL wavelengths at 286 and 300 nm.
差分吸收激光雷达（DIAL）技术通常假定，在用于DIAL测量气体浓度剖面的两个激光波长处，大气光学散射是相同的。当波长显著分开且气溶胶散射分布存在距离依赖性时，这种方法会产生误差。本文讨论了DIAL波长的大分离以及大气中气溶胶的空间不均匀性所引入的误差。提出了一种用于确定紫外区域气溶胶后向散射相对分布的伯努利解，并讨论了这些解的散射比边界值。该方法的结果用于推导对标准DIAL分析方法的后向散射校正。结果表明，对于气溶胶后向散射严重距离依赖性的最坏情况，在286和300 nm的DIAL波长下，校正后的DIAL O3测量中的残余误差<10 ppbv。
