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

Frappart, Frédéric, Ramillien, Guillaume, LeBlanc, Marc, Tweed, Sarah O., Bonnet, Marie-Paule, and Maisongrande, Philippe (2011) An independent component analysis filtering approach for estimating continental hydrology in the GRACE gravity data. Remote Sensing of Environment, 115 (1). pp. 187-204.

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Abstract

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.

Item ID: 20861
Item Type: Article (Refereed Research - C1)
Keywords: filtering technique; gravimetry from space; hydrology; independent component analysis
ISSN: 1879-0704
Date Deposited: 13 Mar 2012 01:28
FoR Codes: 04 EARTH SCIENCES > 0499 Other Earth Sciences > 049999 Earth Sciences not elsewhere classified @ 50%
05 ENVIRONMENTAL SCIENCES > 0599 Other Environmental Sciences > 059999 Environmental Sciences not elsewhere classified @ 50%
SEO Codes: 96 ENVIRONMENT > 9609 Land and Water Management > 960913 Water Allocation and Quantification @ 100%
Citation Count from Web of Science Web of Science 2
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