Don SawyerNASAGSFC

1
The Open Archival Information System
(OAIS)Reference Model and its Usage

• Don Sawyer/NASA/GSFC
• Lou Reich/NASA/CSC
• David Giaretta/BNSC
• Patrick Mazal/CNES
• Claude Huc/CNES
• Michel Nonon-Latapie/CNES
• Nestor Peccia/ESA/ESOC
• October 9-12, 2002

2
Background

• OAIS Reference Model developed by Consultative
  Committee for Space Data Systems
• Work item under ISO TC 20/ SC 13
• Addresses intermediate and indefinite long term
  storage of digital data
• A framework
• for understanding significant relationships among
  the entities of some environment, and
• for the development of consistent standards or
  specifications supporting that environment.

3
Resulting Model

• Model targeted to several categories of reader
• Archive designers
• Archive users
• Archive managers, to clarify digital preservation
  issues and assist in securing appropriate
  resources
• Standards developers
• Already widely adopted as starting point in
  digital preservation efforts
• Digital libraries (e.g., Netherlands National
  Library)
• Traditional archives (e.g., US National Archives)
• Scientific data centers (e.g., National Space
  Science Data Center)
• Commercial Organizations (e.g., Aerospace
  Industries Association preservation working team)

4
Reference Model Status

• Recently published as final CCSDS standard (Blue
  Book) available from
• http//www.ccsds.org/documents/pdf/CCSDS-650.0-B-
  1.pdf
• In publication process as a final ISO standard
  ISO 14721 2002

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Reference Model for anOpen Archival Information
System Brief Technical Overview
6
Open Archival Information System (OAIS)

• Open
• Reference Model standard(s) are developed using a
  public process and are freely available
• Information
• Any type of knowledge that can be exchanged
• Independent of the forms (i.e., physical or
  digital) used to represent the information
• Data are the representation forms of information
• Archival Information System
• Hardware, software, and people who are
  responsible for the acquisition, preservation and
  dissemination of the information

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Purpose, Scope, and Applicability

• Framework for understanding and applying concepts
  needed for long-term digital information
  preservation
• Long-term is long enough to be concerned about
  changing technologies
• Starting point for model addressing non-digital
  information
• Provides set of minimal responsibilities to
  distinguish an OAIS from other uses of archive
• Framework for comparing architectures and
  operations of existing and future archives
• Basis for development of additional related
  standards
• Addresses a full range of archival functions
• Applicable to all long-term archives and those
  organizations and individuals dealing with
  information that may need long-term preservation
• Does NOT specify an implementation

8
Model View of an OAIS Environment

• Producer is the role played by those persons, or
  client systems, who provide the information to be
  preserved
• Management is the role played by those who set
  overall OAIS policy as one component in a broader
  policy domain
• Consumer is the role played by those persons, or
  client systems, who interact with OAIS services
  to find and acquire preserved information of
  interest

OAIS (archive)
Producer
Consumer
Management
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OAIS Information Definition

• Information is always expressed (i.e.,
  represented) by some type of data
• Data interpreted using its Representation
  Information yields Information
• Information Object preservation requires clear
  identification and understanding of the Data
  Object and its associated Representation
  Information

Interpreted Using its
Yields
Data Object
Representation Information
Information Object
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Information Package Definition
Preservation Description Information
Content Information

• An Information Package is a conceptual container
  holding two types of information
• Content Information
• Preservation Description Information (PDI)

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External Data Flow View
Producer
OAIS
queries
result sets
orders
Consumer
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OAIS Functional Entities
Preservation Planning
P R O D U C E R
C O N S U M E R
Data Management
Descriptive Info.
Descriptive Info.
queries
result sets
Ingest
Access
orders
SIP
DIP
AIP
AIP
Archival Storage
Administration
MANAGEMENT
SIP Submission Information Package AIP
Archival Information Package DIP Dissemination
Information Package
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Reference Model Summary

• Reference model is to be applicable to all
  digital archives, and their Producers and
  Consumers
• Establishes common terms and concepts for
  comparing implementations, but does not specify
  an implementation
• Identifies a minimum set of responsibilities for
  an archive to claim it is an OAIS
• Provides detailed models of both archival
  functions and archival information
• Discusses OAIS information migration and
  interoperability among OAISs

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Reference Model for anOpen Archival Information
System Usage Examples
15
Selected non-Space Usage

• Networked European Deposit Library (NEDLIB)
• National Library of the Netherlands
• IBM is developing an implementation recognizing
  OAIS concepts
• British National Library
• Asking IBM to extend its OAIS like
  implementation
• Research Library Group and OnLine Computer
  Library Center
• Developed an OAIS based approach to trusted
  repositories
• Library of Congress
• Hosting an XML based data packaging approach that
  recognizes OAIS Archival Information Package
  concepts

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CNES Plasma Physics Archive Centre de Données
de la Physique des Plasmas (CDPP)

• SIPAD Système dInformation, de Préservation et
  dAccès aux Données(System for Preservation and
  Access to Data and Information)
• this is the computer system developed and
  operated in order to fulfil the CDPP requirements
• Data to be archived at CDPP
• Space plasma data from either space-borne or
  ground-based instruments
• not only experimental data but also orbit,
  attitude, data AND metadata documents,
  bibliographic references, browse, event
  catalogues,any information that makes easier
  the use of data by scientists not involved in
  the space mission or the ground based
  observations
• long term and multi-missions services
• Internet access http//cdpp.cesr.fr

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SIPAD Access to Data and Metadata

• Make temporal-, mission-/experiment-, or
  Keyword-guided selections of data sets
• Build a data request and finally retrieve the
  data from 1 or several data sets files selection
  criteria, on the fly transformation(s) of
  archived files, many delivery options,
• Navigate through the documentation managed at
  CDPP, retrieve documents and abstracts,
• Browse images (multi-missions, different
  selection and display criteria) and select
  interesting time periods
• Use "event tables" (instrument status catalogues,
  magnetospheric activity indices,) to select
  interesting time periods

18
SIPAD Architecture

• For the system architecture
• compliant with the OAIS functional reference
  model(as far as possible because this model was
  under definition in 1997/1998 when SIPAD was
  developing)
• SIPAD architecture separates the different
  functions of the OAIS model ingest, storage,
  data management, access
• Example the data preservation is under STAF
  responsability
• STAF is a CNES facility dedicated to data
  preservation (at the file level)
• File storage location or the storage media can
  be changed with no impact on client systems like
  SIPAD

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CDPP system architecture(S/W and H/W)
Generation of media(SEM)
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Additional Standards Used

• mandatory EAST () description supplied
• both used for data set documentation data
  processing (temporal or field extractions in
  data files  generic  (single) s/w to be
  developped and maintained)() EAST (Enhanced
  Ada SubseT) is a CCSDS standard
• mandatory "date and time format"
  standardization(all CCSDS standards supported)
  used for data selection
• mandatory data set descriptor (compliant to DIF
  (Directory Interchange Format)) supplied
• both used for data set documentation for
  the SIPAD  search tool by keywords  (keywords
  definition)
• definition of a dictionnary ( like  DEDSL from
  CCSDS) defining all the entities and attributes
  to be supplied
• all the information are delivered to the SIPAD in
  PVL (Parameter Value Language)

21
CDPP Results

• this standards approach allows the s/w to be
  generic (multi missions, multi information
  categories), evolutive and secure (several
  controls possible during the acquisition parsing)
• reuse of the SIPAD for 2 other CNES projects
• interoperability with other data centers under
  prototyping
• CDPP User Helpdesk (Email cdpp_at_cesr.fr)

22
National Space Science Data Center

• Data archived at NSSDC (over 20 TB in 4300 data
  sets)
• Space Physics, Astrophysics, and Planetary data
  from mostly space-borne instruments
• not only experimental data but also orbit,
  attitude, data AND metadata documents,
  bibliographic references, browse, event
  catalogues,any information that makes easier
  the use of data by scientists not involved in
  the space mission
• long term and multi-mission services
• DIOnAS and supporting software provide the
  long-term storage and management of the data
• Internet access http//nssdc.gsfc.nasa.gov/

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User Access to NSSDC Data and Metadata

• Make temporal-, mission-/experiment-, or
  Keyword-guided selections of data sets
• Interactively select and retrieve/display using a
  variety of services, including FTP
• Find and access relevant documentation managed at
  NSSDC, retrieve documents and abstracts,
• Customers
• Space physics researchers (NSSDC as active
  archive)
• General public
• NASA/OSS active archives (NSSDC as permanent
  archive)

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NSSDC Architecture

• For the system architecture
• compliant with the OAIS functional
  modelseparates different functions ingest,
  archival storage, data management, access
• Compliant with the OAIS information model
• defines an Archival Information Package (AIP)
  for preservation in Archival Storage
• Data are being migrated into Archival Information
  Packages for long-term storage on DLTs
• New data received arrive as AIPs (e.g., the IMAGE
  project) or are put into AIPs during the Ingest
  process

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NSSDC Archive - Logical Architecture
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NSSDC Results

• This standards approach allows the data to be
  managed, and migrated to new media, independently
  of the nature of the data
• Software and data can be updated independently
• AIP creation software can be used by data
  producers to submit data to the archive
• supports a standard pipeline-processing mode
• provides great Ingest efficiencies for the archive

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Reference URLs

• OAIS Reference Model, CCSDS Blue Book
• http//www.ccsds.org/documents/pdf/CCSDS-650.0-B-
  1.pdf
• ISO Archive Standards Overview Web site
• http//ssdoo.gsfc.nasa.gov/nost/isoas/overview.ht
  ml
• Lavoie, Brian. "Meeting the challenges of digital
  preservation the OAIS reference model". OCLC
  Newsletter. No. 243.January/February 2000. Pages
  26-30. An excellent overview of the OAIS RM and
  Workshops.
• http//www2.oclc.org/oclc/pdf/news243.pdf
• Research Libraries Group has established a web
  page to track OAIS implementation efforts and
  issues
• http//www.rlg.org/longterm/oais.html