Types of dataset: Ssalto/Duacs multimission altimeter products
Contents: multimission sea surface heights computed with respect to a seven-year mean, along-track or gridded (1/8°x1/8° on a regular grid)
Use: regional studies; ocean variability (mesoscale circulation, seasonal variation...), including operational oceanography (near-real time products)
Condition of access :All Ssalto/Duacs product users need an account on FTP, see Access to Ssalto/Duacs data
Description: regional product resulting from specific processes, available in near-real time and in delayed time.
For gridded merged data, a formal mapping error file is also available, with geostrophic velocity anomalies.
Geographic coverage: Mediterranean Sea (30°N-46°N, 5°W-36°E)

Format: NetCDF
Tools :

• User Handook: Ssalto/Duacs User Handbook : (M)SLA and (M)ADT Near-Real Time and Delayed Time Products
• Data reading software

Description: this delayed time product is available in two versions:

• "Ref" (Reference) series: homogeneous datasets based on two satellites (Jason-2 / Envisat  or Jason-1 / Envisat or Topex/Poseidon / ERS) with the same groundtrack. Sampling is stable in time.
• "Upd" (Updated) series: up-to-date datasets with up to four satellites at a given time (Jason-2 / Jason-1 / Envisat from 2009 or between October 2002 and September 2005, the association Jason-1 / Topex/Poseidon / Envisat / GFO). Sampling and Long Wavelength Errors determination are improved, but quality of the series is not homogeneous.

Copyright : 2005-ongoing CLS-Cnes

DT-(M)SLA "Ref"

DT-(M)SLA "Upd"

* During a provisional time (May-June 2010), two different versions of the Ssalto/Duacs-DT data coexist, one on the FTP, now authenticated, the other on the Opendap/the Geographic/temporal extraction tool. Currently, the Opendap and the Geographic/temporal extraction tool give access to the version v2.1.0 of the Ssalto/Duacs-DT data. During Summer 2010, they will integrate the version v3.0.0 of the Ssalto/Duacs-DT data like the authenticated FTP. At this occasion, the access to the Opendap and the Geographic/temporal extraction tool will change and will be authenticated accordingly to the new data policy (see Licence agreement on the subscription form).

Description : the NRT "historical data" are available one month after the date of measurement. The delivery delay for the RT and NRT data is lower: between a 6-day delay and a 0-day delay.
Data period : within a few months at most, from the latest update of the DT products to today (for RT data) to one month ago (for NRT data).
Copyright : 2001-ongoing CLS-Cnes.