A drifting GPS buoy for retrieving effective riverbed bathymetry

JOURNAL OF HYDROLOGY

卷:520

Article

Hostache, R.¹  Matgen, P.¹  Giustarini, L.¹  Teferle, F. N.²  Tailliez, C.¹  Iffly, J. -F.¹  Corato, G.¹ 

[1] CRP Gabriel Lippmann, L-4422 Belvaux, Luxembourg

[2] Univ Luxembourg, Fac Sci Technol & Commun, L-1359 Luxembourg, Luxembourg

关键词: Global Navigation Satellite System (GNSS);    Global Positioning System (GPS);    Water Surface Elevation (WSE);    Effective bathymetry;    Hydrodynamic modeling;    Data assimilation;   

DOI  :  10.1016/j.jhydrol.2014.11.018

来源: Elsevier

【 摘 要 】

Spatially distributed riverbed bathymetry information are rarely available but mandatory for accurate hydrodynamic modeling. This study aims at evaluating the potential of the Global Navigation Satellite System (GNSS), like for instance Global Positioning System (GPS), for retrieving such data. Drifting buoys equipped with navigation systems such as GPS enable the quasi-continuous measurement of water surface elevation, from virtually any point in the world. The present study investigates the potential of assimilating GNSS-derived water surface elevation measurements into hydraulic models in order to retrieve effective riverbed bathymetry. First tests with a GPS dual-frequency receiver show that the root mean squared error (RMSE) on the elevation measurement equals 30 cm provided that a differential post processing is performed. Next, synthetic observations of a drifting buoy were generated assuming a 30 cm average error of Water Surface Elevation (WSE) measurements. By assimilating the synthetic observation into a 1D-Hydrodynamic model, we show that the riverbed bathymetry can be retrieved with an accuracy of 36 cm. Moreover, the WSEs simulated by the hydrodynamic model using the retrieved bathymetry are in good agreement with the synthetic truth, exhibiting an RMSE of 27 cm. (C) 2014 Elsevier B.V. All rights reserved.

【 授权许可】

Free