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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:

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

to get latest product information

DT-ADT "Ref"

Satellite

Distribution media

Frequency

Data period

File weight

Jason-2

FTP

6 months

Jan. 2009 - ongoing

4 MB per file (zipped)

Jason-1

FTP

6 months

August 2002 - ongoing

3.5 MB per file (zipped)

Envisat

FTP

6 months 

June 2003 - ongoing

3.5 MB per file (zipped)

ERS-1

FTP

6 months 

October 1992 - May 1995

1 MB per file (zipped)

ERS-2

FTP

6 months 

May 1995 - June 2003

3 MB per file (zipped)

T/P

FTP

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

FTP

6 months

Jan. 2009 - ongoing

3.5 MB per file (zipped)

Jason-1

FTP
FTP (new orbit)

6 months

August 2002 - Jan. 2009
Feb. 2009 - ongoing 

3.5 MB per file (zipped)

Envisat

FTP

6 months 

June 2003 - ongoing

3.5 MB per file (zipped)

ERS-1

FTP

6 months 

October 1992 - May 1995

1 MB per file (zipped)

ERS-2

FTP

6 months 

May 1995 - June 2003

3.5 MB per file (zipped)

GFO

FTP

6 months 

January 2000 - October 2008

2 MB per file (zipped)

T/P

FTP
FTP (new orbit)

6 months 

September 1992 - August 2002
September 2002 - October 2005

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)

anonymous ftp

30 days

Jason-1

ftp

Daily

3 hours to 3 days

February 2004 - ongoing

2.5 MB per file (zipped)

anonymous ftp

30 days

Envisat

ftp

Daily

3 hours to 3 days

February 2004 - ongoing

3.5 MB per file (zipped)

anonymous ftp

30 days