基于扫描F-P标准具的高光谱分辨低平流层温度探测

Scanning F-P etalon based high spectral resolution lidar for low-stratosphere temperature measurement

报道了一种基于扫描F-P标准具的高光谱分辨低平流层大气温度探测技术.通过扫描F-P标准具,获得大气分子瑞利后向散射的透过率分布.对该透过率进行非线性拟合,由拟合得到的谱宽计算大气温度分布.为了减小频率不稳定引起的系统误差,采用静态的F-P标准具实时监测激光出射频率,并在数据处理中进行补偿.由时间分辨率2000 s的激光雷达原始信号的信噪比,根据最大似然估计误差分析,该方法在30km以下的探测误差小于1.9K,50km以下的探测误差小于9.8K.在对比实验中,在18～36km高光谱分辨激光雷达与探空气球探测的温度廓线最大偏差4.7K;在27～34km,高光谱分辨激光雷达与瑞利积分激光雷达探测的温度最大偏差2.7K.在15～27km,由于气溶胶的污染,瑞利积分激光雷达的温度明显偏离其他两种探测结果,最大偏差达22.8K.

A high spectral resolution lidar（HSRL） for measurement of low stratosphere temperature by scanning Fabry Per ot interferometer （FPI） is proposed and demonstrated. The transmission of Rayleigh backscatter through the FPI is obtained by scanning the cavity spacing of the FPI, and then fitted to Gaussian function using the nonlinear fitting algorithm. Temperature is calculated from the fitted bandwidth of the measured transmission. To reduce systematic error due to frequency instability of the laser, another solid FPI is incorporated into the optical receiver to monitor the frequency drift, which compensates in the data pro cessing. The statistical error is calculated based on a maximum likelihood estimator, which is less than 1.9 K/9.8K below 30 km/50km. In the comparison experiment, the max temperature deviation between the high spectral resolution lidar （HSRL） and radiosonde is 4.7K from 18 km to 36km, and it is 2.7K between the HSRL and Rayleigh integration lidar （RIL） from 27km to 34km. The temperature profile from Rayleigh integration lidar deviates from the results from HSRL and radiosonde obviously from 15km to 27km, with a max deviation of 22.8K, which may due to the aerosol contamination.