Types of dataset: Ssalto/Duacs multimission altimeter products
Contents: gridded sea surface heights above geoid; dynamic topography is the sum of sea level anomaly (SLA) and mean dynamic topography (MDT)
Use: Ssalto/Duacs gridded products are devoted to scientific applications and non-commercial use: study of the general circulation (ocean gyres ...)
Condition of access : All Ssalto/Duacs product users need an account, see Access to Ssalto/Duacs data
Data access service: see Data access service. In NRT, FTP delivers the most recent data (day-0) whereas Opendap/geographic-temporal extraction tool/LAS only delivers data more than one month.
Description: gridded product, provided in near-real time and in delayed time. As a snapshot, each map represents the sea state for a given day. One level of resolution is available (1/3°x1/3°, Mercator grid), but this product is also provided in a second version that is resampled on a 1/4°x1/4° cartesian grid (really destinated to users confused by the Mercator grid).
This product contains absolute geostrophic velocities computed from absolute topography.
Geographic coverage: global
A specific regional product with an improved quality is available in local areas (more information).

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-MADT "Ref"

DT-MADT "Upd"

Description: the NRT data are delivered daily with a 6-day delay, a 3-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.

Copyright: 2001-ongoing CLS-Cnes