ADT - Absolute Dynamic Topography
Types of dataset: Ssalto/Duacs multimission altimeter products
Contents: along-track sea surface heights above geoid; dynamic topography is the sum of sea level anomaly (SLA) and mean dynamic topography (MDT, Rio05 here)
Use: study of the general circulation (ocean gyres ...)
Description: mono altimeter satellite product homogeneous with other satellites, available in near-real time and in delayed time.
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
DT-ADT
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-ADT "Ref"
Satellite | Distribution media | Frequency | Data period | File weight |
|---|---|---|---|---|
Jason-2 | 6 months | Jan. 2009 - ongoing | 4 MB per file (zipped) | |
Jason-1 | 6 months | August 2002 - ongoing | 3.5 MB per file (zipped) | |
Envisat | 6 months | June 2003 - ongoing | 3.5 MB per file (zipped) | |
ERS-1 | 6 months | October 1992 - May 1995 | 1 MB per file (zipped) | |
ERS-2 | 6 months | May 1995 - June 2003 | 3 MB per file (zipped) | |
T/P | 6 months | September 1992 - August 2002 | 3.5 MB per file (zipped) |
DT-ADT "Upd"
Satellite | Distribution media | Frequency | Data period | File weight |
|---|---|---|---|---|
Jason-2 | 6 months | Jan. 2009 - ongoing | 3.5 MB per file (zipped) | |
Jason-1 | 6 months | August 2002 - Jan. 2009 | 3.5 MB per file (zipped) | |
Envisat | 6 months | June 2003 - ongoing | 3.5 MB per file (zipped) | |
ERS-1 | 6 months | October 1992 - May 1995 | 1 MB per file (zipped) | |
ERS-2 | 6 months | May 1995 - June 2003 | 3.5 MB per file (zipped) | |
GFO | 6 months | January 2000 - October 2008 | 2 MB per file (zipped) | |
T/P | 6 months | September 1992 - August 2002 | 3.5 MB per file (zipped) |
RT & NRT-ADT
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: from few hours after the measurements to 3 days.
Condition of access : The NRT "historical data" are freely available via the links below. For RT and NRT data less for one month, see Access to Ssalto/Duacs data .
Data period : within a few months at most, from the latest update of the DT products to today.
Copyright : 2004-ongoing CLS-Cnes.
Satellite | Distribution media | Frequency | Delivery delay | Data period | File weight |
|---|---|---|---|---|---|
Jason-2 | ftp | Daily | 3 hours to 3 days | janvier 2009 - ongoing | 2.5 MB per file (zipped) |
30 days | |||||
Jason-1 | ftp | Daily | 3 hours to 3 days | February 2004 - ongoing | 2.5 MB per file (zipped) |
30 days | |||||
Envisat | ftp | Daily | 3 hours to 3 days | February 2004 - ongoing | 3.5 MB per file (zipped) |
30 days |


