Radar Altimetry Aids Managing Gauge Networks Joecila Santos da Silva & Stéphane Calmant & Frédérique Seyler & Daniel Medeiros Moreira & Daniel Oliveira & Achiles Monteiro Received: 13 July 2011 /Accepted: 21 March 2013 / Published online: 12 January 2014 # Springer Science+Business Media Dordrecht 2014 Abstract The hydrological observation network in the Amazon basin is made of conventional rainfall and water level stations presently maintained by the Agência Nacional de Águas (ANA), the National Agency for Waters. The water level network has long been plagued by difficulties associated with spatial coverage, timely delivery and data errors. Satellite obser- vations are important means for providing hydrologic data with acceptable spatial and temporal resolution, and radar altimeters embarked onboard successive satellites since the early 1970s collect measurements of water level over rivers in a well-defined geodetic reference frame and can be used to address some of these problems. Nowadays, satellite altimetry can be used to collect the time variations of the water levels over many rivers throughout the word, as long as the reach are several hundred meters wide. This ability is particularly interesting in ungauge basins but it can also be used as an independent source of information to cross-check existing gauge series. In the present study, we focus on examples Water Resour Manage (2014) 28:587–603 DOI 10.1007/s11269-013-0484-z J. S. da Silva (*) Centro de Estudos do Trópico Úmido – CESTU, Universidade do Estado do Amazonas – UEA, Avenida Djalma Batista, 3578, Flores, 69050-010 Manaus, AM, Brazil e-mail: jsdsilva@uea.edu.br S. Calmant Institut de Recherche pour le Développement – IRD, UMR 5566 LEGOS CNES/CNRS/IRD/UT3, 14, Av. Edouard Belin, 31400 Toulouse, France e-mail: stephane.calmant@ird.fr F. Seyler Institut de Recherche pour le Développement – IRD, UMR ESPACE-DEV, 0,275 km Route de Montabo, BP 16597323, Cayenne-Guyane, France e-mail: frederique.seyler@ird.fr D. M. Moreira : D. Oliveira : A. Monteiro Serviço Geológico do Brasil – CPRM, Av. Pasteur, 404,Urca, 22290-040 Rio de Janeiro, Brazil D. M. Moreira e-mail: daniel.moreira@cprm.gov.br D. Oliveira e-mail: daniel.oliveira@cprm.gov.br A. Monteiro e-mail: achiles.monteiro@cprm.gov.br