典型滤波器对星载高光谱分辨率激光雷达532 nm通道回波信号的影响

高光谱分辨率激光雷达（High Spectral Resolution Lidar，HSRL）系统利用窄带滤波器将激光雷达回波信号中的大气粒子（云或气溶胶）散射和分子散射成分分开，提升了云或气溶胶光学特性的反演质量。提出了一种基于HSRL探测原理的HSRL回波信号模拟方法，其原理是利用CALIPSO云/气溶胶消光系数产品和数值天气预报数据被用来仿真星载HSRL 532 nm回波信号。两种典型的窄带光谱滤波器:FPI（Fabry-Prot Interferometer）和碘吸收滤波器，作为分子通道滤波器的性能通过仿真的星载HSRL回波信号进行分析。对三种典型:晴空、卷云、气溶胶（两层厚云）的HSRL回波廓线进行详细的敏感分析表明碘分子吸收滤波器的性能明显优于FPI滤波器，其中碘吸收滤波能保持可以忽略不计的相对偏差（4.010-3%），这是由低光学厚度（1.0）的粒子后向散射效应引起的。但是，如果FPI滤波器的粒子后向散射透过率能保持在10-3水平以下，其仍不失为是一个好的选择。

Effect of typical filters on return signals of spaceborne HRSL channel at 532 nm

The future high spectral resolution lidar(HSRL) system employs a narrow spectral filter to separate the particulate(cloud/aerosol) and molecular scattering components in the lidar return signals, which improves the quality of the retrieved cloud/aerosol optical properties. A simulation method of HSRL return signal based on HSRL detection principle was presented. The principle was that the CALIPSO cloud/aerosol extinction coefficient product and numerical weather forecast data were used to simulate the spaceborne HSRL 532 nm return signal. The performance of two typical spectral filters, i.e., Fabry-Prot interferometric(FPI) and iodine absorption filters, were analyzed using the simulated spaceborne HSRL return signals when they used as spaceborne HSRL molecular channel filter. The sensitivity analysis of three typical HSRL echo profiles(clear sky, cirrus cloud, aerosol, two-layer thick cloud) shows that the performance of iodine absorption filter was obviously better than that of FPI filter. The iodine absorption filter can maintain negligible relative deviation (4.010-3%), which was caused by the backward scattering effect of particles with low optical thickness(1.0). However, an FPI filter would still be a good choice for spaceborne HSRL systems if its particulate backscattering transmittance can be maintained below a level of 10-3.