后向散射激光雷达是探测大气气溶胶参数的有力工具,但它存在盲区和过渡区,且需要假设气溶胶的消光后向散射系数比来反演气溶胶的参数,这些限制了它的探测范围和精度。集侧向散射、后向散射和拉曼散射于一体的单波长发射五通道接收激光雷达系统,克服了上述困难。该激光雷达可以探测气溶胶的退偏比廓线、水汽混合比廓线、后向散射系数廓线和消光系数廓线等。气溶胶后向散射系数和消光系数可从地面到对流层顶进行探测,气溶胶退偏比廓线可以在对流层内进行探测,水汽混合比廓线可以在边界层内进行探测。在硬件条件的基础上,分析了各通道的信噪比和探测结果的随机相对误差。实例探测表明:该激光雷达系统数据可靠,探测范围较广。该系统的建立,为进一步深入研究气溶胶消光系数、水汽时空分布以及它们之间相互关系奠定了坚实的实验基础。
Backscattering lidar is a powerful tool for atmospheric aerosol detection, but it can not receive the full signals in lower hundreds of meters, and has an assumption of lidar ratio for aerosol backscattering coefficient reversion. One wavelength emission and five channel receivers lidar system based on backscatter, side-scatter, and Raman scatter technique overcomes the above shortcomings. The system can detect aerosol depolarization ratio profile, water vapor mixing ratio profile, backscattering coefficient profile and aerosol extinction coefficient profile. Aerosol backscattering coefficient and extinction coefficient profile were from the ground to the tropopause, aerosol depolarization ratio profile was in troposphere, and water vapor mixing ratio was in planetary boundary layer. The signal to noise ratios of all channel and relative errors of detected results were analyzed based on the system hardware. Case study indicates that the data of this system are reliable, and detection ranges are rather wide. The system can be used for studying the spatio-temporal distribution of atmospheric aerosol extinction coefficient, water vapor and their relationship.