Apr 24, 2025

Dear SWOT User Community,

The joint NASA/CNES SWOT project is pleased to announce the upcoming transition of SWOT science data products from Version C to Version D.

• The Version D products resolve several known issues in the Version C KaRIn science data products.
• They are generated with updated processing algorithms, calibration parameters, and some geophysical models.
• This release is referred to as Version D0.

 

The Version D KaRIn Science Data Products Release Note provides:

• Information about the dates for this transition.
• How to distinguish the SWOT Version C0, C2, and D0 products using the Composite Release Identifier in the product file names.
• A summary of the most significant changes from Version C0, to C2, to D0 products.
• Links to the User Handbook, Products Description Documents, and Algorithm Theoretical Basis Documents. There have been some small updates to the User Handbook and Product Description Documents since the Version C release, and these updates are already available.
• Lists of the known issues in each of the C0, C2, and D0 products.
• Data access at NASA PO.DAAC, CNES AVISO, and CNES hydroweb.next. Note that the data access areas for Version D products are slightly different from the Version C products.

 

The Major Changes to SWOT Products from Version C to D  package provides more details about the significant changes from Version C to D products. 

Version D products will be generated for all measurements spanning the start of the calibration phase onward, and consist of:

• Reprocessed products for observations from the start of the calibration phase (March 30, 2023) through the end of cycle 31 (~April 27, 2025). The reprocessing of SWOT KaRIn Version D products is scheduled to start in April 2025 and is expected to complete in early 2026.
• Forward-processed products for measurements from April 28, 2025 onward. 
• The last Version C products will be for measurements on April 27, 2025, and will typically become available by May 1, 2025.
• The first Version D products will be for measurements on April 28, 2025, and are expected to become available by May 7, 2025.

 

There will be a short delay in SWOT product availability from approximately May 1-7, 2025 to facilitate this transition from Version C to D products.
However, no gaps in data coverage are anticipated when data distribution resumes by May 7, 2025.

The project will host a Webinar on April 28 and May 19 at 15:00 UTC (08:00 PDT, 11:00 EDT, and 17:00 CET) to describe the most significant changes from Version C to D products.

All users are welcome to attend either of these two occurrences of this Webinar at the Teams link provided below.

The content of these two occurrences is planned to be the same and will consist of two parts:

1. Description of major changes from Version C to D, as shown in attached slides.
2. Review of the reference frame, geodetic coordinates, and reference surfaces used in SWOT products.

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User Services Office
NASA JPL Physical Oceanography DAAC
E-mail: podaac@podaac.jpl.nasa.gov
URL: https://podaac.jpl.nasa.gov
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