Data processing

Transforming raw data into an easily usable form involves a great deal of data processing. The systems that perform this task are a vital component of satellite operations.

Step 1 - Raw telemetry and level 1 data

Raw telemetry from instruments on the satellite is downlinked to Cnes and Nasa ground stations, which forward it to the quality control and processing centers at JPL and Cnes. Telemetry is then processed to obtain level 1 data, i.e., data that are timed and located, expressed in the appropriate units, and checked for quality. This task is performed by the Instrument Control Center (CCI).

Step 2 - Level 1 data and level 2 geophysical data

Level 1 data are corrected for instrument errors and errors due to atmospheric signal propagation and perturbations caused by surface reflection. Geophysical corrections are then applied (solid earth, ocean and pole tides, etc.). Jason-1 altimetry data are processed to this level by the CMA multimission altimetry center, which is part of Ssalto. Ssalto is also responsible for precise orbit determination (POD).

Step 3 - Data validation and qualification

The CMA validates geophysical data for quality assurance. Validation involves precise quality controls and monitoring of instrument drift. This step is an integral part of the processing sequence before giving the go-ahead to generate science products and distribute them to users.

Step 4 - Ssalto/Duacs level 3 and level 4 data:

Level 3 data are validated (off-record data are edited), along-track data. Further computation is performed on level 2 geophysical data (e.g. SSH or SLA). There may be cross-calibration between missions. Level 4 are multi-satellite (cross-calibrated), gridded data.

 

EnglishFrançaisEspañol
Rss feedsContactSitemapPartnersFAQGlossaryLexicon
You must enable cookies in your browser preferences to save the modifications
You are using an older version of Internet Explorer, please update to take full advantage of Aviso+ features

Customize the home page

View all widgets
Reduce display
Public profile
User profile

Select/Deselect widgets

Discover AVISO+

Customizable home, reading tools, products search guide, etc.. Discover step by step the features of the new site AVISO+.

Customizable homepage

The new home page is composed of blocks called "widgets".

Rearrange the blocks with a "Click & Drop".

Hide a widget with the cross at the top right. Reset or add a widget with the "wrench" icon. The "User" and "Public" profiles offer a predefined organization.

All the modifications are automatically saved as cookies on your machine so as to enable you to have your own specific AVISO+.

Reading tools

Ease your reading by choosing the page background colour (black/white) and/or by modifying the font size.

Browsing menu and breadcrum trail

To ease your browsing through AVISO+, you can use at any time the main banner items with the interactive submenus or use the browsing menu on the left side of the screen (it is open by default). For more readiness of the page contents, you can fold and unfold the browsing menu by clicking on the tab. At any time you can know where you are thanks to the browsing menu or the breadcrum at the top of the page.

Products search guide

The first submenu of the "Data" banner item leads you to a new search form enabling you to find quickier the product that suits your needs. The list of results is updated according to your selection criteria.

AVISO+ Multimedia

The first submenu of the "Multimedia" banner item leads you to AVISO+ collections of images and videos linked to altimetry and its applications. Have a nice visit!