150 likes | 253 Vues
An Overview of Selected ISO Standards Applicable to Digital Archives. Science Archives in the 21st Century 25 April 2007 Donald Sawyer - NASA/GSFC/NSSDC Lou Reich - CSC (NASA/GSFC) John Garrett - Raytheon (NASA/GSFC/NSSDC). Overview. NSSDC Standards Participation: Historical Perspective
E N D
An Overview of Selected ISO Standards Applicable to Digital Archives Science Archives in the 21st Century 25 April 2007 Donald Sawyer - NASA/GSFC/NSSDC Lou Reich - CSC (NASA/GSFC) John Garrett - Raytheon (NASA/GSFC/NSSDC)
Overview • NSSDC Standards Participation: Historical Perspective • Selected ISO standards for Archives • Reference Model of an Archive and its Information • Checklist of Activities between Data Providers and Archives • Packaging Data and Metadata with an XML Manifest • Describing Data and Sending it to an Archive • Ensuring Archives can be Trusted to Preserve Information • Wrap-up Views
NSSDC Standards Participation: Historical Perspective • NSSDC formed NASA/Science Office of Standards and Technology (NOST) in 1988 • Created and supported a formal NOST standards development process • NOST FITS Technical Committee formed by Astrophysics discipline • In 1999, NOST Definition of FITS: NOST 100-2.0 • NSSDC began participation in Consultative Committee for Space Data Systems (CCSDS) standards development in 1986 • Data packaging standard (SFDU): ISO 12175 • Data description registration authority procedures: ISO 13764 • Data description packaging for registration: ISO 15395 • PVL data tagging language: ISO 14961 • Data description language EAST specification: ISO 15889 • Data entity dictionary specification: ISO 21961, 21962, 22643 • NSSDC began formally leading Space Physics Archive Search and Extract (SPASE) development for Heliophysics in 2003 • Version 1.1.0 is available for data producers at http://www.spase-group.org/data/doc/spase-1_1_0.pdf
Reference Model of an Archive • Reference Model for an Open Archival Information System (OAIS): ISO 14721 • Standardizes terms, concepts, and basic responsibilities • Addresses functions, information models, migration, federation • Basis for this workshop’s Framework document • Extremely widely adopted • Recognized and used throughout virtually all national archives and digital libraries, and many science data repositories, commercial organizations • NSSDC uses it for internal and external communication
NSSDC Uses OAIS Concepts Archive Information Packages Provenance Information Archival Information Collections Context Information Archive Information Units Reference Information Submission Information Packages Fixity Information Content Information Designated Community Representation Information
Validation Phase Transfer Phase Checklist of Activities between Data Providers and Archives • Producer-Archive Interface Methodology Abstract Standard (PAIMAS): ISO 20652 Develop agreement (data to be delivered, complementary elements, schedule) Phase objective Validate the transferred objects Define the information to be archived Actual transfer of the objects in SIPs Transferred object files Preliminary Phase Formal Definition Phase Preliminary Agreement Dictionary Formal model Submission Agreement Anomalies Validation agreement Data ready to archive
Action table Description Methodology: Preliminary Phase Sub-phases and Actions
Packaging Data and Metadata with an XML Manifest • XML Formatted Data Unit (XFDU): CCSDS 661.0-R-1 • Undergoing formal Space Agency review • ISO review to follow • Supports single file implementation (e.g., zip) • Contains or points to other files • Supports OAIS or custom metadata categorization, mime types, checksums, and transformations such as compression and encryption. • Validation API supports a range of structural and semantic validation capabilities • Prototype java software library available from NASA • Prototype C++ API available from ESA • Current scalability testing to 50 Gbytes
Describing Data and Sending it to an Archive • Producer-Archive Interface Specification (PAIS): CCSDS/ISO Data Archive Ingest WG draft • Formal Space Agency review late summer • ISO review 2008 • Standardized and extensible attributes to describe data objects prior to transfer to archive • Maps data and PAIS information to XFDU packaging standard for transfer • Will leverage and extend XFDU software library
Ensuring Archives can be Trusted to Preserve Information • Digital Repository Audit and Certification: CCSDS/ISO BOF working group • Looking to become chartered CCSDS/ISO Working Group • Build on work completed in other organizations, particularly: • Research Libraries Group/National Archives and Records Administration’s “Trustworthy Repositories Audit & Certification: Criteria and Checklist (TRAC)” • Network of Expertise in long-term STORage Working Group’s “Catalogue of Criteria for Trusted Digital Repositories” • Subject of subsequent presentation at this workshop
Wrap-up Views • Difficult to pre-judge the success of any particular standards effort • May take several years to ‘catch on’ or be superceded • However, OAIS reference model ‘caught on’ in draft stage - large need and good timing! • Significant educational component associated with any standards effort • Another form of research • Contact presenter for more information • Donald.Sawyer@nasa.gov