NODC Jason-2 and Jason-3 Archive Details

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Archive Requirements

The NOAA National Oceanographic Data Center (NODC), as the designated archive for the Jason-2 (OSTM) and Jason-3 data, is a segment of the NOAA Jason Ground System (NJGS). As the public interface to the Jason mission data, NODC is committed to providing high-quality archive services and data discovery, access and visualization methods to support a wide range of audiences from the general public to expert members of the Ocean Surface Topography Science Team (OSTST) and members of the Jason-2 and -3 Science Working Teams.

Archive Services

All critical archive functions necessary for the preservation of Jason-2 (OSTM) data have been established and rigorously tested through the comprehensive NOAA and Four Partner Operational Readiness Reviews. An ISO description for each Jason-2 (OSTM) data family has been written and is available in CLASS. ISO 19115 descriptions for Jason-3 will be developed in 2012. Quality Assurance for Jason-2 (OSTM) at ingest into the archive is maintained using a system known as NRTAVS, which was developed by JPL under contract with NOAA. It extends the near real time quality monitoring established for Jason-1 to include Jason-2 (OSTM). NODC has also established the Jason Rich Inventory (JRI) system for Jason-2 (OSTM) Geophysical Data Records which is being enhanced and operationalized for Jason-3. At present, standards-based services such as direct ftp, http and OPeNDAP for the X-GDR data are supported directly by NODC although these functions are anticipated to transition to CLASS at some point in the future. The NODC archive accessions for the six Jason-2 (OSTM) datatypes are given below. Note that these links point only to the metadata:

1. Level-2 X-Geophysical Data Records (O/I/GDR)
2. Ancillary Files
3. Auxiliary Files
4. Near Real-Time Altimetry Validation System (NRTAVS) QA Reports
5. Orbital Information
6. Packet Telemetry

Archive Roles

NODC has provided leadership in preservation planning and stewardship oversight of the entire archive process, including high-level access to and visualization of the science data as well as efforts to ensure its quality, and its connection with data from the other altimeter missions, including GEOSAT, which is now also preserved for the long-term in the NODC archive.

History of the Jason-2 (OSTM) Submission Agreement

In early 2005, based on a Request to Archive process under consideration by the Data Archive Board (now known as the Data Management Committee), it was agreed that the drafting of an archive Submission Agreement would be the appropriate way to clearly establish and document the Jason-2 (OSTM) and Jason-3 archive strategy. This Submission Agreement would document the relationships between the Archive, consisting of CLASS and NODC, and the Producer, consisting of the NOAA Environmental Satellite Processing Center (ESPC), which generates the local Jason-2 (OSTM) and Jason-3 products and provides those created by CNES. The negotiations to create this Submission Agreement were conducted by Kenneth Casey for NODC, Jeremy Throwe for CLASS, and John Lillibridge of NESDIS STAR, who represented the NOAA, EUMETSAT, and CNES producers. The process of drafting the Jason-2 (OSTM) and Jason-3 Submission Agreement gained momentum as the partners realized that the negotiations were addressing critical questions related to the short-term usability and the long-term understanding and preservation of the data. The partners all agreed that standards-compliant formats would be critical, and netCDF with Climate/Forecast (CF) file-level metadata attributes was chosen to store the mission products. Standard names for altimetry observations were debated within the CF community and are now under consideration for approval. Greater unrestricted access to the full mission data was advocated, with some successes. The great majority of the mission data and all mission products are publicly available, but CNES still requires limited access to some ancillary fields provided by ECMWF and to telemetry data.