Abstract's details

CTOH altimetry products (L1 to L4) for ocean and continental surfaces applications

Florence Birol (Florence.Birol@legos.obs-mip.fr, France)


Fabien Blarel (CTOH/LEGOS, France); Denis Blumstein (CNES, France); Sara Fleury (CTOH/LEGOS, France); Frédéric Frappart (CTOH/GET, France); Nicolas Fuller (CTOH/LEGOS, France); Benoit Legresy (CNRS, France); Rosemary Morrow (CTOH/LEGOS, France); Fernando Niño (CTOH/LEGOS, France)

Event: 2015 Ocean Surface Topography Science Team Meeting

Session: Outreach, Education and Altimetric Data Services

Presentation type: Type Poster

Contribution: not provided


The Center for Topography of the Oceans and Hydrosphere (CTOH) is a French Observation Service created in 1989 and dedicated to satellite altimetry studies. Its objectives are to 1) maintain and distribute homogeneous altimetric databases for ocean, hydrosphere and cryosphere applications, 2) help scientific users to develop new altimetry derived products and 3) contribute to the development and validation of new processing approaches of the altimetric data for emerging research domains (coastal ocean, continental surface water monitoring, cryosphere, ...).

The CTOH maintains homogeneous altimetric GDR data bases for the following missions : Topex/Poseidon, GFO, ENVISAT, Jason-1, Jason-2, Saral/Altika and Cryosat2 (ESA, CNES). Except for GFO, all these products are provided in netcdf format. A very new version of ERS-2 data, reprocessed by the CTOH, including both ICE-1 and ICE-2 retrackers and all the usual corrections is also now available (see posters by Legresy et al.). Jason-3 and Sentinel-3 will be added soon after the data areavailable.

Both 1Hz and 10/20/40Hz data are available globally (for oceans and continental surfaces). The CTOH database contains L1 products (waveforms) as well, for some altimeter missions. We also add about 20 recent altimetry corrections and auxiliary parameters in a homogeneous way to all GDRs. It includes tide models, DAC, MSS, geoids, and tropospheric corrections. New geophysical corrections are being developed for continental surfaces applications and distributed.

In addition, the CTOH works on developing new altimetric products :

• Coastal products : Along-track SLA time series are available in 23 different regions, computed with the X-TRACK software designed for coastal altimetry processing (…/products/coastal-products). A regional product of along-track tidal harmonic constants (including the amplitude, phase lag and error estimates for a number of tidal constituents), computed by harmonic analysis of X-TRACK 1-Hz SLA, is also available. In 2015, X-TRACK code was rewritten and the editing strategy revisited (see poster by Fuller et al.).

• High resolution products: Over the open ocean, multi-satellite data approaches are being developed to improve the mapping and representation of finer-scale structures in gridded regional maps. Lagrangian techniques are also used to recreate finer-scale structures in ocean tracer fields (e.g. temperature and salinity) using the lateral stirring from gridded altimetric currents. These have been developed in a number of test regions.

• Continental hydrology products : including the “Hydroweb” data base for monitoring river and lake levels (…/products/hydroweb). Hydroweb integrates the CASH project: Topex reprocessed data over terrestrial surface waters. Water level maps are also developed for 5 rivers: the Amazon, Orenoque, Gange-Bramhapoutre, Congo and Mekong.

All these products are now progressively re-distributed via AVISO+, our new common platform with AVISO: http://www.aviso.altimetry.fr/en/home.html.

More information can be found on the CTOH website http://ctoh.legos.obs-mip.fr/.

Poster show times:

Room Start Date End Date
Grand Ballroom Foyer Thu, Oct 22 2015,11:00 Thu, Oct 22 2015,18:00
Florence Birol