GRACE大气去混频模型计算的若干策略分析  

Strategies and analysis for the computation of GRACE atmospheric de-aliasing models

作　　者：游为 熊大伟 方伟浩 YOU Wei;XIONG DaWei;FANG WeiHao(Faculty of Geosciences and Environmental Engineering,Chengdu 611756,China;Nanjing Metro Operation Co.,Ltd.,Nanjing 210008,China)

机构地区：[1]西南交通大学地球科学与环境工程学院,成都611756 [2]南京地铁运营有限责任公司,南京210008

出　　处：《地球物理学进展》2023年第3期1059-1073,共15页Progress in Geophysics

基　　金：国家自然科学基金面上项目(41974013,42174014)资助。

摘　　要：非潮汐高频大气质量变化需要在时变重力场模型的计算过程中予以扣除.本文从大气垂直积分与大气积分平均值算法改进与优化、大气积分平均值时间跨度选择和大气输入数据更新等方面出发,提出若干大气去混频模型计算策略,并从谱域、空域、时域等角度进行模型质量评估.结果表明:基于ERA-Interim数据及本文改进的大气垂直积分算法计算SWJTU1模型,在空域上与RL06的差距小于2 mm大地水准面高,与RL05的差距在14 mm以内;基于ERA5再分析数据计算SWJTU2模型,在空域上与RL06差距小于SWJTU1与RL06的差距,其与SWJTU1的模型差异在0.4 mm内.本文实验结果表明:大气垂直积分算法改进和输入数据的更新都能提高模型质量,但是算法改进的提升程度更大;大气垂直积分平均值的改进算法极大提高了模型计算效率,且对模型质量的影响可以忽略,本文认为平均值的时间跨度应当尽可能长.本文提出的计算大气去混频模型的若干策略,亦可为我国自主研发的重力卫星数据处理提供参考.De-aliasing products is employed to reduce high-frequency mass anomalies in the current state-of-the-art of satellite gravity data processing.In this paper,several strategies for the calculation of atmospheric de-aliasing model are proposed from aspects of the refinement and optimization over the algorithm of calculating atmospheric vertical integration and it's long-term mean fields,together with the selection of its time span as well as the enhancing of the input atmospheric fields for calculating the models.Comparisons between models determined in our methods and those official ones are performed from perspectives of(time)spectral domain,spatial domain and C00 coefficient to validate the value of our strategies.The results indicate that,based on the ERA-Interim data,the gap between SWJTU1 and RL06 is less than 2 mm geoid height in the space domain,while the gap between SWJTU1 and RL05 is less than 14 mm;another set of comparisons between our new product SWJTU2,which uses the enhanced ERA5 reanalysis data as well as the refined calculation method proposed in this paper with RL06 and SWJTU1 reveals a global variation in space domain of 2 mm geoid height and 0.4 mm geoid height,respectively.Combined with other product assessing strategies we propose,all the results tell that the refinement of atmospheric vertical integration algorithm together with the enhancement of input atmospheric fields can receive an improvement in the quality of the de-aliasing model,nevertheless,the former enhancement shows a greater impact on model quality;besides,the optimized algorithm of atmospheric vertical integration average greatly improves the calculation efficiency in time,which leaves a negligible gap as well;experiments also demonstrate that the alternative time span of vertical integration average should be long enough.Strategies concerning atmospheric de-aliasing models in this thesis canbe employed as well into the China's self-developed gravity satellite data processing for references.

关 键 词：地球重力场 GRACE 大气去混频模型 ERA-INTERIM ERA5 球谐分析 

分 类 号：P223[天文地球—大地测量学与测量工程]