An independent component analysis filtering approach for estimating continental hydrology in the GRACE gravity data

REMOTE SENSING OF ENVIRONMENT

卷:115

Article

Frappart, Frederic¹  Ramillien, Guillaume^2,3  Leblanc, Marc⁴  Tweed, Sarah O.⁴  Bonnet, Marie-Paule^1,5  Maisongrande, Philippe^6,7 

[1] Univ Toulouse, UPS, OMP, LMTG, F-31400 Toulouse, France

[2] Univ Toulouse, UPS, OMP, DTP, F-31400 Toulouse, France

[3] CNRS, OMP, DTP, F-31400 Toulouse, France

[4] James Cook Univ, Sch Earth & Environm Sci, Hydrol Sci Res Unit, Cairns, Qld, Australia

[5] LMTG, OMP, IRD, F-31400 Toulouse, France

[6] Univ Toulouse, UPS, OMP, LEGOS, F-31400 Toulouse, France

[7] CNES, F-31400 Toulouse, France

关键词: Filtering technique;    Gravimetry from space;    Hydrology;    Independent component analysis;   

DOI  :  10.1016/j.rse.2010.08.017

来源: Elsevier

【 摘 要 】

An approach based on Independent Component Analysis (ICA) has been applied on a combination of monthly GRACE satellite solutions computed from official providers (CSR, JPL and GFZ), to separate useful geophysical signals from important striping undulations. We pre-filtered the raw GRACE Level-2 solutions using Gaussian filters of 300, 400, 500-km of radius to verify the non-Gaussianity condition which is necessary to apply the ICA. This linear inverse approach ensures to separate components of the observed gravity field which are statistically independent. The most energetic component found by ICA corresponds mainly to the contribution of continental water mass change. Series of ICA-estimated global maps of continental water storage have been produced over 08/2002-07/2009. Our ICA estimates were compared with the solutions obtained using other post-processing of GRACE Level-2 data, such as destriping and Gaussian filtering, at global and basin scales. Besides, they have been validated with in situ measurements in the Murray-Darling Basin. Our computed ICA grids are consistent with the different approaches. Moreover, the ICA-derived time series of water masses showed less north-south spurious gravity signals and improved filtering of unrealistic hydrological features at the basin-scale compared with solutions obtained using other filtering methods. (C) 2010 Elsevier Inc. All rights reserved.

【 授权许可】

Free