GPS measurements applied to the leveling of hydrological stations in the Amazon basin
Abstract
A common reference altitude for hydrological stations is needed for hydrological and hydrodynamic studies. This is also essential to evaluate the quality of hydrological data derived by the techniques of satellite altimetry. However, defining and maintaining such reference at the scale of the Amazon basin with a centimeter level accuracy is tricky because : - of the difficulty in accessing the hydrological stations and getting GPS data - the network is wide, sparse and far from permanent GPS stations - some of the sites are affected by more than 10 centimeters vertical displacement variations caused by hydrological loading. This poster proposes a method of leveling the hydrological stations of the Amazon basin using GPS data, for that we selected 7 permanent GPS stations in the Amazon basin, 6 stations from RBMC-Brazilian Permanent GPS Network and one water level station equipped with permanent receiver installed by CPRM/IRD on Madeira river where the GRACE results show the peak of vertical displacements in Amazon basin . Their coordinates were estimated weekly using a global network of 32 IGS reference stations and processing double-difference ionospheric-free phase observations. The seasonal hydrological loading signal on each of these GPS station has been derived from the series of coordinates. These sites were then used for: - altitude referencing of the closest hydrological stations - kinematic GPS profile adjustments over rivers of the Amazon Basin - water level comparison to satellite altimetry results GPS data were processed using the GINS scientific software developed by CNES/GRGS.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.G23C0708M
- Keywords:
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- 1200 GEODESY AND GRAVITY;
- 1800 HYDROLOGY