摘要
大气水汽含量随海拔升高急剧减小,为准确获得水汽浓度随高度的分布,设计多波长发射水汽探测星载距离分辨差分吸收激光雷达(DIAL)。选取波长相差较小,水汽吸收截面不同的4个发射波长:其中3个吸收截面较大的波长作为信号光束,第4个吸收截面较小的波长作为参考光束,分3组对不同海拔高度处的水汽浓度进行分段探测。对4个发射波长的回波信号进行了仿真模拟,为验证其水汽探测能力,在白天和夜晚对3组波长水汽浓度探测的相对误差进行分析讨论。结果表明,在相对误差小于20%的情况下,该多发射波长星载距离分辨差分吸收激光雷达系统可以实现白天对流层(小于12 km)、夜晚平流层底以下(小于15 km)水汽浓度的探测。理论上初步证实了该多波长星载距离分辨差分吸收激光雷达能全天时精确地探测对流层水汽浓度分布。
The concentration of atmospheric water vapor decreases sharply as the attitude increases. In order to obtain an accurate distribution of water vapor in atmosphere, a spaceborne range-resolved differential absorption lidar （DIAL） of multiple wavelengths emission is designed. Four wavelengths are identified with small diffeerences in wavenumbers, and with different water vapor absorption cross sections, where three wavelengths with larger cross sections are considered to be signal beams, and the last one with smaller cross section is called the reference beam. Divided into three groups, the concentrations of water vapor at different elevations can be segmentally detected. The echo signals of the four wavelengths are simulated. To verify the performance of water vapor profiles detection, the random systematic relative errors of three groups detections of DIAL from spaceborne platforms in daytime and nighttime are evaluated. The analysis shows that, under relative error less than 20%, water vapor profile measurement is possible under troposphere （less than altitude of 12 km） in daytime, and under the bottom of the stratosphere （less than altitude of 15 km） at night. It is theoretically and preliminary proved that the multiple wavelengths spaceborne range-resolved DIAL has the ability of accurate detection of water vapor concentration distributions in troposphere.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2015年第2期279-284,共6页
Chinese Journal of Lasers
基金
国家自然科学基金(61178072)
关键词
大气光学
距离分辨差分吸收激光雷达
星载系统
水汽遥感
多波长探测
atmospheric optics
range-resolved differenctial absorption lidar
spaceborne system
water vapor remote sensing
multiple wavelengths detection
