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SLA - Sea Level Anomalies

Types of dataset: Ssalto/Duacs multimission altimeter products
Contents: along-track sea surface heights computed with respect to a seven-year mean
Use: study of ocean variability (mesoscale circulation, seasonal variation, El Niño...), including operational oceanography (near-real time products)
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-SLA

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.
  • SLA

Copyright : 2005-ongoing CLS - Cnes

to get latest product information

DT-SLA "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

4 MB per file (zipped)

Envisat

FTP

6 months 

June 2003 - ongoing

3 MB per file (zipped)

ERS-1

FTP

6 months 

October 1992 - May 1995

3 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 MB per file (zipped)

DT-SLA "Upd"

Satellite

Distribution media

Frequency

Data period

File weight

Jason-2

FTP

6 months

Jan. 2009 - ongoing

4 MB per file (zipped)

Jason-1

FTP
FTP (new orbit)

6 months

August 2002-Jan. 2009
since Feb. 2009 

4 MB per file (zipped)

Envisat

FTP

6 months 

June 2003-ongoing

3 MB per file (zipped)

ERS-1

FTP

6 months 

Oct. 1992-May 1995

3 MB per file (zipped)

ERS-2

FTP

6 months 

May 1995-June 2003

3 MB per file (zipped)

GFO

FTP

6 months 

January 2000-October 2008

4 MB per file (zipped)

T/P

FTP
FTP (new orbit)

6 months 

Sep.1992-Aug. 2002
Sep.2002-Oct.2005

3 MB per file (zipped)

RT & NRT-SLA

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 : 2001-ongoing CLS-Cnes.

Satellite

Distribution media

Frequency

Delivery delay

Data period

File weight

Jason-2

FTP

Daily

3 hours to 3 days

few months

2.5 MB per file (zipped)

Anonymous FTP

30 days

Jason-1

FTP

Daily

3 hours to 3 days

few months

2.5 MB per file (zipped)

Anonymous FTP

30 days

Envisat

FTP

Daily

3 hours to 3 days

few months

3 MB per file (zipped)

Anonymous FTP

30 days