A technique was developed and the optimal parameters were selected for solving the inverse problem of determining the total content (TC) of R-11 freon (CCl₃F) from ground-based spectrometric measurements of solar radiation at the St. Petersburg NDACC station using an IFS 125HR Fourier interferometer and SFIT4 software. The main features of the technique were the spectral interval of 830–860 cm^–1 and the previously measured instrument spectral sensitivity function. Continuum absorption of radiation by water vapor and attenuation of radiation by the fi lm of amorphous ice deposited on the receiver were also taken into account. The spectral baseline was corrected by a second-order polynomial and the vertical distribution of water vapor was refi ned to compensate for the variability of the ice-film thickness during solution of the inverse problem. The technique was used to determine the TC of R-11 during 2009–2019. The estimated measurement errors were average systematic error 7.4%; random, 2.9% for the entire observation period. The longterm trend of the TC was assessed as –0.29 ± 0.07%/yr; mean volume concentration, –0.31 ± 0.07%/year.

中文翻译：

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透明光谱反演技术用于评估Ccl 3 f氟利昂的大气含量

开发了一种技术，并选择了最佳参数来解决反问题，即使用圣彼得堡NDACC站的太阳辐射的地面光谱法测量来确定R-11氟利昂（CCl ₃ F）的总含量（TC）IFS 125HR傅里叶干涉仪和SFIT4软件。该技术的主要特点是光谱间隔为830–860 cm ^–1以及先前测量的仪器光谱灵敏度功能。还考虑了水蒸气对辐射的连续吸收以及沉积在接收器上的无定形冰膜对辐射的衰减。通过二阶多项式校正光谱基线，并修正水蒸气的垂直分布，以补偿反问题求解期间冰膜厚度的变化。该技术用于确定2009-2019年间R-11的TC。估计的测量误差为平均系统误差7.4％；随机，整个观察期间为2.9％。TC的长期趋势估计为–0.29±0.07％/年；平均体积浓度，–0.31±0.07％/年。