1. Standard Metadata in Scientific Data Formats Ted.Habermann@noaa.gov September 19, 2007 Flash at: http://nosc.noaa.gov/dmc/docs/metadata/player.html

2. Metadata Provided with a Level 3 SST Product From SWFSC Observations of Metadata in netCDF Files Metadata Provided with a Level 3 SST Product From CLASS <attribute name="references" type="String" value="NOAA POES satellites information: http://www.oso.noaa.gov/poes/index.htm. Processing link: http://www.osdpd.noaa.gov/PSB/PSB.html. Processing reference: Walton C. C., W. G. Pichel, J. F. Sapper, D. A. May. The development and operational application of nonlinear algorithms for the measurement of sea surface temperatures with the NOAA polar-orbiting environmental satellites. J.G.R., 103: (C12) 27999-28012, 1998. Cloudmask reference: Stowe, L. L., P. A. Davis, and E. P. McClain. Scientific basis and initial evaluation of the CLAVR-1 global clear/cloud classification algorithm for the advanced very high resolution radiometer. J. Atmos. Oceanic Technol., 16, 656-681. 1999. Calibration and Validation: Li, X., W. Pichel, E. Maturi, P. Clemente-Colà ;³n, and J. Sapper. Deriving the operational nonlinear multi-channel sea surface temperature algorithm coefficients for NOAA-15 AVHRR/3. International Journal of Remote Sensing, Volume 22, No. 4, 699 - 704, March 2001a. Calibration and Validation: Li, X, W. Pichel, P. Clemente-Colón, V. Krasnopolsky, and J. Sapper. Validation of coastal sea and lake surface temperature measurements derived from NOAA/AVHRR Data. International Journal of Remote Sensing, Vol. 22, No. 7, 1285-1303, 2001b." /> The obvious difference in the quantity and quality of metadata available in these two netCDF files prompted me to begin thinking about how we can take advantage of improving content in metadata repositories as we write data into scientific data formats. Today I will share some of those thoughts.

3. Metadata Definitions NoneAll Amount of Collection Level Metadata in Granule Granule Metadata - metadata that documents a specific entity, usually a file, archived or requested by a user from an archive. Historically granule metadata are closer to the data and, therefore, more specialized. Dates, spatial extents and local statistics are examples of granule metadata. Collection Metadata - metadata that documents an entire collection of granules or dataset. Generally more Standard. Examples include DIF/FGDC/ISO metadata records in Geospatial One-Stop or GCMD. Where on this Spectrum Might We Belong?

4. Metadata Partnerships Data Provider Direct Users Archive Designated Community (Archive Users) Partnership Granule Metadata - Created by Data Provider for Real-time customers. Collection Level Metadata - Created at archive for data discovery Partnership

5. Archive Process Evolution Standard Metadata Standard Products Users Designated Community Heterogeneous Format Dependent Tools Present Archive Homogeneous Data and Metadata, Standard Tools Rich Granule Inventory Future Archive? Submission Information Package (SIP)

6. Metadata in this Process Collection Metadata Repository FGDC XML NcML Granule Metadata Repository Rich Inventory XSLT + netCDF Writer Data SIP AIP Submission Information PkgArchive Information Pkg

7. Archive Information Package Content AIP Convention MetadataCollection MetadataGranule Metadata

8. netCDF writer knows 1.collection to convention crosswalks so that convention metadata can be constructed from NcML 2.metadata crosswalks so that multiple metadata conventions can be supported in AIPs Who Does What? Collection Metadata Repository FGDC XML NcML Rich Inventory XSLT + netCDF Writer Data SIP AIP Submission Information PkgArchive Information Pkg NcML holds collection elements 1. needed to support conventions 2. netCDF profiles for FGDC? DC? ISO? 3. User dependent - can this be written dynamically as part of WCS response? netCDF writer adds convention metadata netCDF writer adds granule metadata

9. THREDDS Metadata AIP THREDDS Catalog 1) The THREDDS Catalog Generator can extract selected collection or granule metadata from the files and include it in the catalog. 2) The Metadata_Link attributes could be extracted to support a THREDDS Metadata Service.

10. ISO Metadata AIP MD_AggregateInformation + aggregateDataSetName [0..1] : CI_Citation + aggregateDataSetIdentifier [0..1] : MD_Identifier + associationType : DS_AssociationTypeCode + initiativeType [0..1] : DS_InitiativeTypeCode InitiativeTypes + campaign + collection + exercise + experiment + investigation + mission + sensor + operation + platform + process + program + project + study + task + trial ISO Objects

11. Conclusion It seems likely that real-time and archive users can benefit from convergence of ideas that have developed around granule and collection metadata. I have proposed an approach to including collection metadata in netCDF files and making collection metadata available through metadata services in THREDDS Catalogs. Hopefully those ideas can contribute to this convergence. Questions or suggestions: ted.habermann@noaa.gov