CTOH: from L1 to L4 altimeter data
Sara
Fleury
LEGOS/CTOH
Poster
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 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.
The CTOH maintains homogeneous altimetric GDR data bases for the following missions :
Topex/Poseidon ; GFO ; ENVISAT ; Jason-1; Jason-2 ; Saral/Altika ; Cryosat2. Retracking of
ERS-1 and ERS-2 waveform with the ICE-2 algorithm is underway (see dedicated poster).
Both 1Hz and 10-20-40Hz data are available over all possible oceanic and continental
surfaces.
In addition we add about 20 recent corrections in a homogeneous way to all of the
missions. These include tide models, DAC, MSS, geoids, and new tropospheric corrections.
In addition, the CTOH works on developing and distributing new altimetric products which
today can be accessed from the web site (http://ctoh.legos.obs-mip.fr/products). In the future,
these will be distributed via the new AVISO ODES Online Data Extraction Service (see
dedicated poster). These include :
Coastal products : Alongtrack data are available in a dozen regions, with specific X-TRACK
processing in the coastal band. SLA are available on a nominal groundtrack (1hz and 20hz for
some regions), as well as a high-resolution MSS (…/products/coastal-products). This product
includes tidal constants : amplitude and phase lag with error estimations for each tidal
constituent (see dedicated poster).
Continental hydrology products : including the “Hydroweb” data base for monitoring river
and lake levels (…/products/hydroweb). Hydroweb now integrates the CASH project Topex
reprocessed data over terrestrial surface waters.
Global SubMesoscale filaments. Amplitude and position of sub-mesoscale filament barriers
calculated from gridded AVISO surface currents using the Finite-Size Lyapunov Elements
(d’Ovidio et al., 2009), at 4 km resolution from 1993 to today (…/products/submesoscalefilaments).
Advection products: Surface tracer fields, such as SSS and SST, are stirred by AVISO
surface currents. This allows us to simulate submesoscale structures in observed large-scale
tracer fields (see dedicated poster).
The CTOH also provides altimetric expertise to users and the space agencies based on
waveform analyses over all surfaces, and analyses of corrections and algorithms adapted to
different surfaces, for past, present (Jason-2, Cryosat-2 and SARAL), and future altimetric
missions such as SWOT.
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 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.
The CTOH maintains homogeneous altimetric GDR data bases for the following missions :
Topex/Poseidon ; GFO ; ENVISAT ; Jason-1; Jason-2 ; Saral/Altika ; Cryosat2. Retracking of
ERS-1 and ERS-2 waveform with the ICE-2 algorithm is underway (see dedicated poster).
Both 1Hz and 10-20-40Hz data are available over all possible oceanic and continental
surfaces.
In addition we add about 20 recent corrections in a homogeneous way to all of the
missions. These include tide models, DAC, MSS, geoids, and new tropospheric corrections.
In addition, the CTOH works on developing and distributing new altimetric products which
today can be accessed from the web site (http://ctoh.legos.obs-mip.fr/products). In the future,
these will be distributed via the new AVISO ODES Online Data Extraction Service (see
dedicated poster). These include :
Coastal products : Alongtrack data are available in a dozen regions, with specific X-TRACK
processing in the coastal band. SLA are available on a nominal groundtrack (1hz and 20hz for
some regions), as well as a high-resolution MSS (…/products/coastal-products). This product
includes tidal constants : amplitude and phase lag with error estimations for each tidal
constituent (see dedicated poster).
Continental hydrology products : including the “Hydroweb” data base for monitoring river
and lake levels (…/products/hydroweb). Hydroweb now integrates the CASH project Topex
reprocessed data over terrestrial surface waters.
Global SubMesoscale filaments. Amplitude and position of sub-mesoscale filament barriers
calculated from gridded AVISO surface currents using the Finite-Size Lyapunov Elements
(d’Ovidio et al., 2009), at 4 km resolution from 1993 to today (…/products/submesoscalefilaments).
Advection products: Surface tracer fields, such as SSS and SST, are stirred by AVISO
surface currents. This allows us to simulate submesoscale structures in observed large-scale
tracer fields (see dedicated poster).
The CTOH also provides altimetric expertise to users and the space agencies based on
waveform analyses over all surfaces, and analyses of corrections and algorithms adapted to
different surfaces, for past, present (Jason-2, Cryosat-2 and SARAL), and future altimetric
missions such as SWOT.
OSTS session
Outreach, Education and Altimetric Data Services