ABSTRACT

This paper presents an efficient line-by-line (LBL) technique for the fast computation of compact and precise spectral lookup tables (LUTs) for LBL radiative transfer models. The key feature of this technique is obtaining and using efficient non-uniform wavenumber grids for line profile interpolations with a given accuracy. Grid points are concentrated at the centre of the lines and are rare in the wings. In case of narrow and isolated spectral lines, this technique derives LUTs that are compact by several orders of magnitude than those that use uniform grids. The potential of this technique is demonstrated using the problem of calculating non-Voigt line profiles, as suggested by Hartmann and Tran (HTP). The size of LUTs for the replacement of direct calculations of HTPs in forward remote sensing models is estimated, and a set of LUTs for H₂O lines are created and written as ASCII files in http://wadis.saga.iao.ru/view/hartmann-tran/. Furthermore, the conditions under which this technique can speed up (by approximately one order of magnitude) forward LBL models are discussed.

摘要

本文提出了一种有效的逐行（LBL）技术，用于快速计算LBL辐射传递模型的紧凑和精确的光谱查找表（LUT）。该技术的关键特征是以给定的精度获取并使用有效的非均匀波数网格进行线轮廓插值。网格点集中在线条的中心，在机翼上很少见。在窄且孤立的谱线的情况下，该技术所得出的LUT比使用统一网格的LUT紧凑几个数量级。如Hartmann和Tran（HTP）所建议的，使用计算非Voigt线轮廓的问题证明了该技术的潜力。估计用于替换前向遥感模型中HTP的直接计算的LUT的大小，并为H设置一组LUT在http://wadis.saga.iao.ru/view/hartmann-tran/中创建_2条O行并将其写为ASCII文件。此外，讨论了该技术可以加速（大约一个数量级）正向LBL模型的条件。