Ssalto/Duacs products use Jason-1, Envisat, GFO, ERS-1, ERS-2 and Topex/Poseidon data. File format is NetCDF, but the system also delivers images in Postscript format (only for gridded products).
Several variations of the same or similar products exist:
- merged data, in opposition to data from one satellite
- Reference / up-to-date historical datasets
- Global / regional products
- High / low resolution maps
- Formal mapping error maps
- Real time processing
For both DT and NRT products, the above acknowledgement has to be cited: "The altimeter products were produced by Ssalto/Duacs and distributed by Aviso with support from Cnes".
Ssalto/Duacs product fact sheets
Ssalto/Duacs products are described in fact sheets available on this website. Each fact sheet includes Delayed and (Near-) Real time products.
Orbit quality depends among other things on delay between measurement and data delivery. Thus altimetry sea surface height data, that use the orbit as input, are of a better accuracy with a delay than in real or near-real time. So Near-Real Time data (NRT) are to be used preferentially for operational applications, i.e. applications that need the most recent data, whereas for studies, climatologies, etc. Delayed-Time (DT) data are the best choice.