Han Yajuan, Wu Xiaoqing, Luo Tao, Qing Chun, Yang Qike, Jin Xiaomei, Liu Nana, Wu Su, Su Changdong
J Opt Soc Am A Opt Image Sci Vis. 2020 Jun 1;37(6):995-1001. doi: 10.1364/JOSAA.387211.
It is worth highlighting that, for the first time to the best of our knowledge, vertical profiles of atmospheric parameters and $C_n^2$ were measured at Lhasa, south of the Tibetan Plateau, using balloon-borne radiosondes. Based on the measurements, two new statistical models (Lhasa HMN and Lhasa Dewan) for estimating turbulence strength are proposed. Attention has been paid to evaluate the reliability of the two models to reconstruct vertical profiles of $C_n^2$ from a statistical perspective. The statistical analyses presenting the Lhasa HMN model are accompanied with lower bias, root mean square error (RMSE), and bias-corrected RMSE ($\sigma$) than those of the Lhasa Dewan model, which implies the Lhasa HMN model can better reveal the nature of turbulence characteristics of Lhasa influenced by unique local weather conditions. In addition, the comparison between the Lhasa HMN model and measurements in calculating integrated astroclimatic parameters is carried out, and the result suggests that the performance of the Lhasa HMN model is reliable and satisfactory. The new reliable $C_n^2$ model offers new insight into the characteristics of optical turbulence at Lhasa and provides support for pursuing astronomical site selection in the Tibetan Plateau.
值得强调的是，据我们所知，这是首次使用气球携带的无线电探空仪在青藏高原南部的拉萨测量大气参数和大气折射指数结构参数 $C_n^2$ 的垂直剖面。基于这些测量结果，提出了两种用于估计湍流强度的新统计模型（拉萨HMN模型和拉萨德万模型）。已从统计角度对这两种模型重建 $C_n^2$ 垂直剖面的可靠性进行了评估。与拉萨德万模型相比，展示拉萨HMN模型的统计分析具有更低的偏差、均方根误差（RMSE）和偏差校正均方根误差（$\sigma$），这意味着拉萨HMN模型能够更好地揭示受当地独特天气条件影响的拉萨湍流特性的本质。此外，还对拉萨HMN模型与计算综合天文气候参数时的测量结果进行了比较，结果表明拉萨HMN模型的性能可靠且令人满意。这个新的可靠的 $C_n^2$ 模型为拉萨光学湍流特性提供了新的见解，并为在青藏高原进行天文选址提供了支持。
