Abstract's details

CTOH studies for extending the range of altimetry applications over the ocean and continental surfaces

Fabien Blarel (LEGOS-CNRS, France)


Damien Allain (LEGOS, France); Florence Birol (LEGOS, France); Denis Blumstein (CNES, France); Robin Chevrier (LEGOS, France); Lucrèce DJEUMENI (Legos, France); Wassim Fkaier (Legos, France); Frederic Frappart (LEGOS, France); Yvan Gouzenes (LEGOS, France); Fabien Leger (LEGOS, France); Rosemary Morrow (LEGOS, France); Fernando Niño (LEGOS, France)

Event: 2022 Ocean Surface Topography Science Team Meeting

Session: Outreach, Education and Altimetric Data Services

Presentation type: Type Poster

Contribution: PDF file


The Center for Topography of the Oceans and Hydrosphere (CTOH) is a French Observation Service created in 1989 and dedicated to satellite altimetry studies. It focuses on the development and promotion of new processing approaches of the altimetric data for emerging research domains (coastal ocean, oceanic sub-mesoscale phenomenons, continental surface water, sea ice, polar caps). It works in close relationship with space agencies (mainly CNES and ESA) at different levels for satellite altimetry missions: preparation of new missions, definition of the user’s needs, CAL/VAL studies, signal analysis & data reprocessing, development of thematic products, teaching and outreach.
In terms of data distribution, the CTOH maintains a global GDR data base for almost all altimetry missions since Topex/Poseidon. All the products are made homogeneous (addition of the most recent parameters / corrections for the old missions) and provided in netcdf format. A new version of ERS-2 data, reprocessed by the CTOH for hydrological applications is also available (it includes ICE-1 and ICE-2 retrackers). Both 1Hz and 10/20/40Hz data are available globally. For some products, the CTOH database contains also L1 products (waveforms).
In addition, the CTOH develops new altimetry products:
• Fine-resolution ocean products: position of the main Southern Ocean polar fronts and global climatology of near-inertial current characteristics.
• Coastal products : X-TRACK along-track SLA time series and tidal harmonic constants, reprocessed with a software designed for coastal altimetry, but also the recent high-resolution (20-Hz) X-TRACK/ALES sea level product, now reaching a distance of 3-4 km from the coast on average (see Leger et al., OSTST 2022). These products are distributed by AVISO+ and by ESA, respectively.
• Continental hydrology products : including Topex/Poseidon reprocessed by the CASH project and water level maps developed for 5 rivers: the Amazon, Orenoque, Gange-Bramhapoutre, Congo and Mekong.
It also contributes to the development of sea-ice products distributed by AVISO+ (Arctic Sea Ice Thickness and Snow depth monthly maps over sea ice) and to the “Hydroweb” data base for monitoring river and lake levels.


Poster show times:

Room Start Date End Date
Mezzanine Tue, Nov 01 2022,17:15 Tue, Nov 01 2022,18:15
Mezzanine Thu, Nov 03 2022,14:00 Thu, Nov 03 2022,15:45
Fabien Blarel