卫星探测通道晴空大气吸收透过率快速计算研究进展  

An overview of fast calculation to clear atmospheric absorption transmittance of satellite channel

作　　者：马刚 郭杨[4,5,6] 苏婧[7] 白文广 张鹏[4,5,6] MA Gang;GUO Yang;SU Jing;BAI WenGuang;ZHANG Peng(Center for Earth System Modeling and Prediction of CMA,Beijing100081,China;Key Laboratory of Earth System Modeling and Prediction,China Meteorological Administration,Beijing100081,China;State Key Laboratory of Severe Weather(LaSW),Chinese Academy of Meteorological Sciences,China Meteorological Administration,Beijing100081,China;National Satellite Meteorological Center,Beijing100081,China;Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites,Beijing100081,China;Innovation Center for FengYun Meteorological Satellite(FYSIC),Beijing100081,China;College of Atmospheric Science,Lanzhou University,Lanzhou730000,China)

机构地区：[1]地球系统数值预报中心,北京100081 [2]中国气象局地球系统数值预报重点开放实验室,北京100081 [3]灾害天气国家重点实验室,北京100081 [4]国家卫星气象中心,北京100081 [5]中国遥感卫星辐射测量和定标重点开放实验室,北京100081 [6]许健民创新中心,北京100081 [7]兰州大学大气科学学院,兰州730000

出　　处：《地球物理学报》2023年第6期2275-2291,共17页Chinese Journal of Geophysics

基　　金：国家重点研发计划(2018YFC1506701)资助。

摘　　要：大气透过率计算是辐射传输模拟的核心,快速、精确的卫星通道透过率计算方法在卫星资料仿真与反演、卫星资料同化等领域有极大的应用价值.本文综合论述了卫星通道透过率快速模拟技术的研究进展,内容包括基于Taylor展开、最优光谱采样、主分量分析以及机器学习理论等方法的论述,分析了不同代表性模型的基本原理、模拟精度以及存在的问题.在快速透过率模拟的订正方面,本文分析了云水吸收对卫星微波通道透过率的订正,并对模拟透过率的直接订正、辐射传输的光学路径订正、通道光谱中的气体重叠吸收订正以及气体连续吸收订正等方面进行了分析和讨论.本文还论述了我国在卫星通道透过率快速模拟和透过率订正技术的研究进展及存在的问题.指出,快速透过率模拟的首要应用对象是变分框架下的卫星通道辐射资料同化,其本质是把基于吸收强度、谱线线型等复杂物理过程转化为在数学空间高度线性化的计算方法.基于Taylor展开和基于最优光谱采样方法,快速计算有效层光学厚度是当前主流的卫星通道透过率快速计算途径.而如何重新定义不依赖于卫星天顶角的预报因子、将更多的可变气体从均匀混合气体中分离出来,以及定义充分而又具有足够伴随精度的预报因子集合、卫星观测倾斜路径的射线追踪订正等技术是进一步提高卫星观测模拟精度的关键所在.基于上述分析,本文最后还提出我国当前和未来卫星通道透过率快速仿真正演的发展前景.Atmospheric transmittance is the core of the infrared radiation transmission calculation and fast and accurate calculation approaches in channel transmittance make it possible for infrared remote sensing and satellite data assimilation.This paper firstly comprehensively reviews the progress of fast simulation techniques of satellite channel transmittance in terms of the Taylor expansion,the optimal sampling,the principal component analysis and the theory of machine learning,together with the basic principle,precision and problems of different typical simulation models.For rapid correction of transmittance simulation,this paper analyzes and discusses those approaches by cloud water absorption in microwave channel transmittance,radiative transfer optical path,channel spectra overlapping of gas absorption and gas content in aspects of continuous absorption.Then it discusses the progress and problems related to the rapid simulation of satellite channel transmittance and transmittance correction technologies in China.It points out that the essence of rapid transmittance simulation is to transfer the complex physics processes,such as absorption intensity and spectral lines,into a highly simplified mathematical space,and the fast calculation based on the Taylor expansion and the effective optical thickness by the optimal spectrum sampling are the current mainstream of fast channel transmittance calculations.It also points out that the future direction of RTTOV(Radiative Transfer for TIROS the Operational Vertical Sounder(TOVS))is how to redefine those forecast factors which can be independent on the zenith Angle of the satellite,how to separate more variable gases from mixing gases,and how to define the forecast factors in perfect precision.Finally,this paper puts forward the orientations of fast simulations of current and future satellite channel transmittance for Chinese satellites.

关 键 词：卫星 大气吸收 透过率 快速计算 

分 类 号：P401[天文地球—大气物理学与大气环境]