GRGS > Research > Subjects > Spatial Altimetry

Bureau des longitudes Centre national d’études spatiales Institut national de l'information géographique et forestière - Laboratoire LAREG Observatoire de Paris Institut national des sciences de l'Univers Observatoire de la Côte d'Azur Service Hydrographique et Océanographique de la Marine Observatoire Midi-Pyrénées Université de la Polynésie Française Ecole Supérieure des Géomètres et Topographes - Conservatoire national des arts et métiers Ecole et Observatoire des Sciences de la Terre

Spatial Altimetry

Altimeter Calibration: from the Ocean to Inland Waters

The incomparable precision achieved in the framework of the TOPEX / Poseidon mission has led to many studies on changes in sea level (generally estimated at 3 mm / year). Consequently, the study of bias and drift in altimeter measurement requires closer attention, that is, precision of 1 mm / year or less. The effect of these deviations in instrument readings can in fact falsely distort readings of sea level variation during a mission, but the analysis of absolute bias of the instruments is also very important for combining long series of altimetric data from different missions.

Monitoring the TOPEX / Poseidon, Jason-1 and Jason-2 missions is carried out at the absolute calibration site in Corsica. Developed in 1996 in collaboration with CNES, this project also helps monitor the level of the Mediterranean. In addition, new techniques using GPS are deployed there (tropospheric corrections, GPS buoys) to improve the validation of various measurements used to determine sea surface height.

Finally, along with tradition studies of the marine environment, we are also interested in the calibration of altimeter measurements on inland waters (lakes, rivers...) using in-situ measurements at dedicated sites that will be developed or improved through these experiments.

Calibration Altimétrique: de l’océan aux Eaux Continentales (Corse)

Calibration Altimétrique: de l’océan aux Eaux Continentales (Corse)

P. Bonnefond1 , P. Exertier1 , O. Laurain1 , F. Pierron1 , Y. Ménard2 , F. Lyard3, S. Calmant3, J.-F. Crétaux3, L. Testut3, G. Jan4 and V. Ballu5 

1 OCA/GeoSciences Azur, Grasse, France
2 CNES, Toulouse, France
3 LEGOS, Toulouse, France
4 NOVELTIS, Ramonville, France
5 IPGP, Paris France