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Sequential estimation of surface water mass changes from daily satellite gravimetry data / Guillaume L. Ramilien in Journal of geodesy, vol 89 n° 3 (March 2015)  

Public [article]  inJournal of geodesy > vol 89 n° 3 (March 2015) . - pp 259 - 282 Titre : Sequential estimation of surface water mass changes from daily satellite gravimetry data Type de document : Article/Communication Auteurs : Guillaume L. Ramilien, Auteur ; Frédéric Frappart, Auteur ; S. Gratton, Auteur Année de publication : 2015 Article en page(s) : pp 259 - 282 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] Amazone (fleuve) [Termes IGN] Amérique du sud [Termes IGN] analyse diachronique [Termes IGN] bande K [Termes IGN] carte thématique [Termes IGN] données GRACE [Termes IGN] estimation statistique [Termes IGN] filtre de Kalman [Termes IGN] levé gravimétrique [Termes IGN] masse d'eau [Termes IGN] océanographie spatiale [Termes IGN] variation temporelle Résumé : (auteur) We propose a recursive Kalman filtering approach to map regional spatio-temporal variations of terrestrial water mass over large continental areas, such as South America. Instead of correcting hydrology model outputs by the GRACE observations using a Kalman filter estimation strategy, regional 2-by-2 degree water mass solutions are constructed by integration of daily potential differences deduced from GRACE K-band range rate (KBRR) measurements. Recovery of regional water mass anomaly averages obtained by accumulation of information of daily noise-free simulated GRACE data shows that convergence is relatively fast and yields accurate solutions. In the case of cumulating real GRACE KBRR data contaminated by observational noise, the sequential method of step-by-step integration provides estimates of water mass variation for the period 2004–2011 by considering a set of suitable a priori error uncertainty parameters to stabilize the inversion. Spatial and temporal averages of the Kalman filter solutions over river basin surfaces are consistent with the ones computed using global monthly/10-day GRACE solutions from official providers CSR, GFZ and JPL. They are also highly correlated to in situ records of river discharges (70–95 %), especially for the Obidos station where the total outflow of the Amazon River is measured. The sparse daily coverage of the GRACE satellite tracks limits the time resolution of the regional Kalman filter solutions, and thus the detection of short-term hydrological events. Numéro de notice : A2015-338 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0772-2 Date de publication en ligne : 05/11/2014 En ligne : https://doi.org/10.1007/s00190-014-0772-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76707 [article]