使CO2浓度测量误差减小的星载激光雷达波长优化

研究了星载积分路径差分吸收（IPDA）激光雷达系统工作波长与大气CO2 分子柱线浓度测量误差之间的关系，并优化波长以降低测量误差。首先介绍CO2 分子柱线浓度测量原理，理论分析并模拟仿真了系统随机误差、温度不确定性误差、频率不稳定性误差和水蒸汽干扰误差随激光雷达工作波长变化关系，优化工作波长使浓度测量总误差达到最小值。最终选定激光雷达on-line波长为6361.2250cm-1，off-line 波长为6 360.99 cm-1，并仿真计算得到温度不确定性为1 K、频率不稳定度为0.6 MHz 时，共导致的CO2 柱线浓度测量误差为0.58710-6，达到CO2 浓度测量精度110-6 的要求，为星载IPDA 激光雷达系统实现高精度CO2 柱线浓度探测优化系统参数提供了参考。

Wavelengths optimization to decrease error for a space-borne lidar measuring CO2 concentration

The relationship between atmospheric column-averaged CO2 concentration measurement errors and operating wavelengths of space-borne integrated path differential absorption (IPDA) lidar was studied. The column-averaged CO2 concentration measurement principle was presented, and the system random error, temperature uncertainty error, frequency drift error and H2O interference error as a function of the operating wavelengths of lidar were analyzed. The operating wavelengths were optimized to minimize the total concentration measurement error. For optimal IPDA lidar on-line and off-line wave number of 6 361.225 0 cm-1 and 6360.99cm-1, the total column-averaged CO2 concentration measurement error was calculated to be 0.58710-6 with 1K temperature error and 0.6MHz frequency drift error, which meets the requirement of the column- averaged CO2 concentration measurement with 110-6 accuracy. The optimized wavelengths are applicable for retrieval of column-averaged CO2 concentration with high precision for space-bore IPDA system.