研究基于ChiGaM卫星星间位差反演Mascon模型,反演过程中采取的策略包括:1)引入分段加速度(piece-wise constant acceleration,PCA)参数以减弱动力学定轨过程中力模型误差的影响;2)采用考虑至3-CPR(cycle per revolution)的经验模型吸收...研究基于ChiGaM卫星星间位差反演Mascon模型,反演过程中采取的策略包括:1)引入分段加速度(piece-wise constant acceleration,PCA)参数以减弱动力学定轨过程中力模型误差的影响;2)采用考虑至3-CPR(cycle per revolution)的经验模型吸收星间位差中的低频噪声;3)融合多源数据构建正演模型和参数先验约束矩阵。处理2022-03—2023-12期间卫星数据,构建Mascon模型IEU-CGS-Monthly2023M。与GRACE-FO卫星同时期Mascon模型产品对比,结果表明,所反演模型计算的全球与区域质量分布变化与对比模型具有较高的一致性;各模型大地水准面阶误差在信号占优阶次内高度重合;在9个选定流域内,所反演模型与对比模型的平均相关系数大于0.9;模型整体表现与对比模型相近。本文利用ChiGaM卫星星间位差实现了高精度Mascon模型反演,验证了卫星获取重力场时变信号的能力,可为相关数据处理及应用提供参考。展开更多
Global Navigation Satellite System(GNSS)observations are critical for establishing high-precision terrestrial reference frames(TRF),but the environmental loading effects,particularly hydrological loading deformation(H...Global Navigation Satellite System(GNSS)observations are critical for establishing high-precision terrestrial reference frames(TRF),but the environmental loading effects,particularly hydrological loading deformation(HYLD),remain unaccounted in existing TRF like ITRF2020,limiting their accuracy.This study evaluates the performance of multiple HYLD datasets derived from GRACE(mascon and spherical harmonic(SH)products)and four hydrological models(LSDM,ERA5,GLDAS2,and MERRA2)in explaining seasonal and non-seasonal GNSS displacements globally using IGS Repro3 and Re pro 2datasets.Among these six HYLD datasets,we demonstrate that the GRACE mascon solution achieves superior performance in explaining the seasonal and non-seasonal GNSS displacements,by quantifying the amplitude reduction ratio(AMPR)and root mean square reduction ratio(RMSR)induced by HYLD corrections,respectively.The mascon-derived HYLD achieves better correction,particularly with the vertical median AMPR of 35.1%and RMSR of 4%.In contrast,hydrological models and SH product have relatively lower performance in explaining GNSS displacements,with ERA5 achieving only 24.7%for the ve rtical AMPR.The HYLDs of coastal stations generally exhibit worse perfo rmance with lower AMPR and more negative RMSR distributions,likely reflecting the influence of ocean loading and their limitations in accurately isolating the land water signal within land boundaries;whereas the mascon result shows minimal differences between inland and coastal stations,benefitting from the reduced leakage of land water into the oceans.Furthermore,the transition from Repro2 to the improved reprocessing strategy in Re pro3 enhances the overall consistency between HYLDs and GNSS displacements,specifically with a 7%improvement in the vertical AMPR with MERRA2.展开更多
The primary mission of the Gravity Recovery and Climate Experiment (GRACE) satellite and its successor,GRACE Follow-On (GRACE-FO), is to provide time-variable gravity fields, and its observations have been widely used...The primary mission of the Gravity Recovery and Climate Experiment (GRACE) satellite and its successor,GRACE Follow-On (GRACE-FO), is to provide time-variable gravity fields, and its observations have been widely used in various studies. However, the nearly one-year gap between GRACE and GRACE-FO has affected our ability to obtain continuous time-variable gravity data. In this study, we use the Singular Spectrum Analysis (SSA) method to fill the nearly one-year gap between the GRACE and GRACE-FO missions, as well as the gaps within the GRACE mission itself, to generate a continuous and complete mascon product from April 2002 to December 2022. These products are evaluated at the basin scale in Greenland, Antarctica, and ten river basins worldwide, as well as across oceans. The results show that our filled data can effectively recover seasonal and interannual signals and exhibit good consistency with previous reconstructions. The products provided in this study will benefit GRACE applications related to oceans, glaciers, and terrestrial water storage.展开更多
文摘研究基于ChiGaM卫星星间位差反演Mascon模型,反演过程中采取的策略包括:1)引入分段加速度(piece-wise constant acceleration,PCA)参数以减弱动力学定轨过程中力模型误差的影响;2)采用考虑至3-CPR(cycle per revolution)的经验模型吸收星间位差中的低频噪声;3)融合多源数据构建正演模型和参数先验约束矩阵。处理2022-03—2023-12期间卫星数据,构建Mascon模型IEU-CGS-Monthly2023M。与GRACE-FO卫星同时期Mascon模型产品对比,结果表明,所反演模型计算的全球与区域质量分布变化与对比模型具有较高的一致性;各模型大地水准面阶误差在信号占优阶次内高度重合;在9个选定流域内,所反演模型与对比模型的平均相关系数大于0.9;模型整体表现与对比模型相近。本文利用ChiGaM卫星星间位差实现了高精度Mascon模型反演,验证了卫星获取重力场时变信号的能力,可为相关数据处理及应用提供参考。
基金sponsored by the National Natural Science Foundation of China,China(Grant Nos.42174028,42474030,and 41774007)Major Science and Technology Program of Hubei Province,China(Grant No.JSCX202501188)the Natural Science Foundation of Wuhan,China(Grant No.2024040701010029)。
文摘Global Navigation Satellite System(GNSS)observations are critical for establishing high-precision terrestrial reference frames(TRF),but the environmental loading effects,particularly hydrological loading deformation(HYLD),remain unaccounted in existing TRF like ITRF2020,limiting their accuracy.This study evaluates the performance of multiple HYLD datasets derived from GRACE(mascon and spherical harmonic(SH)products)and four hydrological models(LSDM,ERA5,GLDAS2,and MERRA2)in explaining seasonal and non-seasonal GNSS displacements globally using IGS Repro3 and Re pro 2datasets.Among these six HYLD datasets,we demonstrate that the GRACE mascon solution achieves superior performance in explaining the seasonal and non-seasonal GNSS displacements,by quantifying the amplitude reduction ratio(AMPR)and root mean square reduction ratio(RMSR)induced by HYLD corrections,respectively.The mascon-derived HYLD achieves better correction,particularly with the vertical median AMPR of 35.1%and RMSR of 4%.In contrast,hydrological models and SH product have relatively lower performance in explaining GNSS displacements,with ERA5 achieving only 24.7%for the ve rtical AMPR.The HYLDs of coastal stations generally exhibit worse perfo rmance with lower AMPR and more negative RMSR distributions,likely reflecting the influence of ocean loading and their limitations in accurately isolating the land water signal within land boundaries;whereas the mascon result shows minimal differences between inland and coastal stations,benefitting from the reduced leakage of land water into the oceans.Furthermore,the transition from Repro2 to the improved reprocessing strategy in Re pro3 enhances the overall consistency between HYLDs and GNSS displacements,specifically with a 7%improvement in the vertical AMPR with MERRA2.
基金the National Natural Science Foundation of China(E3ER0402A2,E421040401)the University of Chinese Academy of Sciences Research Start-up Grant(110400M003)the Fundamental Research Funds for the Central Universities(E2ET0411X2).
文摘The primary mission of the Gravity Recovery and Climate Experiment (GRACE) satellite and its successor,GRACE Follow-On (GRACE-FO), is to provide time-variable gravity fields, and its observations have been widely used in various studies. However, the nearly one-year gap between GRACE and GRACE-FO has affected our ability to obtain continuous time-variable gravity data. In this study, we use the Singular Spectrum Analysis (SSA) method to fill the nearly one-year gap between the GRACE and GRACE-FO missions, as well as the gaps within the GRACE mission itself, to generate a continuous and complete mascon product from April 2002 to December 2022. These products are evaluated at the basin scale in Greenland, Antarctica, and ten river basins worldwide, as well as across oceans. The results show that our filled data can effectively recover seasonal and interannual signals and exhibit good consistency with previous reconstructions. The products provided in this study will benefit GRACE applications related to oceans, glaciers, and terrestrial water storage.
