Earthdata Forum

Hi CDDIS Analysis Team,
I am currently working with the Jason-2/DORIS orbit products available through the NASA Crustal Dynamics Data Information System (CDDIS), specifically the files from version E of the Geophysical Data Record (GDR-E). They can be accessed at ftp://doris.ign.fr/pub/doris/products/orbits/ssa/ja2/GDR-E.
These products, which include coordinates and velocities provided by SSALTO, are essential to our analysis.
However, I noticed that the files do not contain any explicit information regarding the precision or accuracy of the coordinates and velocities, unlike the GPS precise orbit files, where accuracy information is typically available.
Could you please clarify whether the precision of the orbit data (coordinates and velocities) is documented somewhere for the GDR-E files, or if there is a way to estimate the accuracy of these products?
Thank you for your assistance, and I look forward to your response.
Best regards,
Ruby

Hi Ruby,

It’s no problem at all, thank you for your interest!

I can’t speak exactly to Jason-2’s orbit accuracy for each individual file but I can reference work that I found in the IDS website.

Here’s a bibliography of online publications that have cited the DORIS system: https://ids-doris.org/ids/reports-mails/doris-bibliography/on-line-publications.html

More specifically here’s a presentation from 2014 describing the PODs from the Analysis Center at CNES in the framework of the ITRF2013: https://ids-doris.org/images/documents/report/publications/OSTST2014-PODatCNESCLSAnalysisCenterforIDS.pdf
- I believe that slide 7 might be the info you’re looking for, it shows the Radial / Cross-Track / Along-Track independently over time for Jason-2

Thanks again for the question, and I hope this helps!

- Taylor