CCSDS Panel 2 Packaging Standards

1
CCSDS Panel 2 Packaging Standards

• David Giaretta

2
Space Information Interchange Services

• that facilitate the preservation, access, and
  exchange of space mission-related information
  across the Global Information Infrastructure and
  the space mission information systems
  infrastructurethese services will increase the
  value of information gathered from space by
  enabling it to be transparently used by current
  and future users of the information infrastructure

3
Space Data vs ordinary data

• Space Data does NOT limit the scope of the
  panel
• The Standards and associated tools developed by
  the Panel are applicable to ALL types of
  information
• However the panel has tended to focus on binary
  data with complex metadata e.g.
• Earth Observation images
• Space Plasma datasets
• Astronomical images
• i.e. not just text

4
Information leakage
5
Metadata Management
Searchable catalogue data
Updatable
locate metadata
Metadata
Metadata repository
Metadata
Data
Data
Request data
Data repository
6
Packaging concepts

• Broad division of classes
• Structure
• handle the packaging
• Service
• Service mechanisms
• Data
• Actual data

7
Structure

• Container data unit
• Hierarchical container packing
• Application data unit contains
• objects of application data and any related
  ancillary or identification data objects required
  to process them
• Description data unit - contains
• A unique Data Description identifier with which
  it can be located
• All data description objects (e.g., DDRs, DEDs,
  supplementary description data) necessary to
  interpret the described LVOs.

8
Service

• Replacement
• Logical insert external data object
• Associate identifier with external dtaa object
• Logically concatenate external data objects
• Data Administration
• Parameters used for data administration
• Object naming
• Referencing registered information

9
Data

• Application data object
• Object of primary interest
• Supplementary data object
• Various data useful for understanding, evaluating
  or processing relationship undefined
• Data Description Record data object
• Description of the syntax
• Data Dictionary data object
• Semantic information
• Catalogue attributes data object
• Attributes not defined
• Volume production data object
• E.g. processing history

Need rules for which data object can be contained
within which Structure Unit
10
Label-Value-Object (LVO)

• LABEL contains sub-fields
• An identifier of the format and meanings of all
  the other LABEL sub-fields
• An identifier of the description of the format
  and meaning of the data in the VALUE field (ADID)
• Gives LOCATION and ID of the data description
• An identifier that gives an indication of the
  type of data in the VALUE field
• The necessary information required to delimit the
  VALUE field
• VALUE field
• may contain any form of data
• LABEL field specifies
• method used to delimit this field
• description of the data in this field
• Delimitation technique for object must be
  specified
• Length
• By Pattern
• End of file

11
CCSDS Panel 2 Standards

• Data Description languages
• EAST plus related tools
• Parameter Value Language (PVL)
• (some similarities to XML)
• XML-based
• JAVA-based
• Data Dictionary Specification Language
• Abstract, XML and PVL syntax

12

• Structures for data transfer
• Conceptual as well as concrete
• For data and metadata
• Metadata registry
• For long-term access to metadata
• Procedures standardised
• Tools available

13
Long-term Preservation of Information

• Open Archival Information Systems (OAIS)
  Reference Model
• Standards arising from OAIS
• Ingest
• standard ingest forms
• standard ingest methodology
• Certification
• Data Identification for Archival Information
  Packages
• Access Dissemination

14
Context other developments

• Global Information Infrastructure
• W3C
• OMG
• Other ISO standards bodies
• GRID

15
Problems

• Specialised code needed for the specific
  packaging
• Maintenance of software is a problem
• Contents for catalogue not specified
• Relationships between objects limited