大气压力是最重要的气象要素之一。为了实现空间激光遥感大气压力,需要先进行必要的地基激光雷达探测实验研究。以单纵模Nd∶YAG激光器的二倍频532 nm激光脉冲作为泵浦源,以KTP(KTiOPO4)晶体作为非线性转换介质的光参量振荡器和光参量放大器,产生了760.236 nm和760.307 nm 波长的两种激光脉冲,脉冲能量为40 mJ,采用?350 mm望远镜接收大气的后向散射,从而获得了不同高度处与激光雷达之间双波长的差分光学厚度。有效探测高度为500~4000 m,时间分辨率为1~5 min。实验结果表明,差分光学厚度对应着大气层不同高度处与激光雷达间的压力差,其对应关系的数值表达是可以期待的。

Atmospheric pressure is one of the most important meteorological parameters. In this work, to realize spaceborne laser remote sensing of atmospheric pressure, ground-based lidar measurement investigations are conducted. A 532-nm laser pulse produced by the second-frequency of a single longitudinal-mode Nd∶YAG laser is used as a pump source. An optical parametric oscillator and an optical parametric amplifier using a KTP (KTiOPO4) crystal as a nonlinear conversion medium generate two laser pulses with wavelengths of 760.236 and 760.307 nm, with the pulse energy reaching 40 mJ. A ?350-mm telescope receives the backscattering of the atmosphere, the differential optical depth of two wavelengths between different altitudes and the lidar is obtained. The effective detection altitudes range of the ground-based differential absorption lidar is 500--4000 m, and the time resolution is 1--5 min. The investigations show that the differential optical depth corresponds to the pressure difference between different altitudes of the atmosphere and the lidar, and a numerical expression of the corresponding relationship can be obtained.