CoAuthors

Stéphane Calmant (LEGOS/IRD, France); Félix Perosanz (GET/CNES, France); Jean-François Cretaux (LEGOS/CNES, France); Adrien Paris (CLS, France); Joécila Santos da Silva (UEA, Brazil); Frédérique Seyler (Espace/IRD, France); Otto Rotunno Filho (UFRJ, Brazil)

Since the work presented by Hall et al. (2012), ICESAT has little been used for hydrology in the Amazon basin. In the present work, we present an update of the validation of the ICESAT data (GLA14 V34). Taking into account the slope of the river surface gained during GPS cruises when comparing the ICESAT measurements of height of the water surface with gauge readings, we show that ICESAT was actually a very accurate instrument in monitoring water surfaces, performing much better than stated by Hall et al. (2012). Yet, because it was not placed on a suitable orbit, ICESAT could not be used to monitor the water level changes at dedicated locations. In turn, we propose a methodology to use ICESAT to accurately level the in-situ gauges, taking avantage of the dense spatial coverage of the successive ICESAT tracks. Besides, we show that ICESAT is an independant dataset suitable for checking for potential errors in the readings. Given that ICESAT-2 is expected to perform even better than ICESAT, use of ICESAT-2 data this way could qualify the readings when these are expected to serve as a ground truth for other altimetry missions such as the SWOT mission.