[Moims-dai] MOIMS-DAI responses to MOSSG

[Mark Conrad]

Well said, David!



On Wed, Sep 14, 2016 at 10:34 AM, David Giaretta <david at giaretta.org> wrote:

> As discussed at the DAI webex yesterday, and with further exchanges of
> emails, here is a collection of comments on the MOSSG paper.
>
>
>
> ..David
>
>
>
> 1)      Although the paper states “Archive ingestion is not considered
> part of the IOAG interoperability goals.”, nevertheless as is recognised in
> “However, the assumption is that there are mechanisms for archive ingestion
> implemented”, it will not be possible to get data out of an archive unless
> data is ingested into it. MOIMS-DAI covers data ingest and should be
> mentioned in the document, for example CCSDS 651.1-B-1, Producer-Archive
> Interface Specification (PAIS). Blue Book. Issue 1. February 2014.
>
> 2)      The use of the word archive is misleading. What is discussed in
> most of the document is what might be termed “short-term storage”. For
> example, the Service Description of the kind “Archive of Agency Y is
> accessed by Agency X to…”, which implies simple access to the bits which
> have been stored. Interoperability normally means being able to use the
> bits.
>
> The MOIMS-DAI work on archives is about maintaining the usability of the
> bits.
>
> If agencies X and Y use the same format and semantics for the bits then
> there is no problem. If one the other hand they do not then agency X will
> need additional information. This may be relevant if there is a long time
> between the creation of the data by Agency Y and the use by Agency X. It
> may also be relevant if there is very little time between creation and use,
> for example if the agencies use different systems.
>
> This is recognised in slide 29 in the PowerPoint presentation which has,
> at the top level (with additions/changes marked in red):
>
> *Integration levels*
>
> *Archiving*
>
> *Degree*
>
> *of Interoperability*
>
> Ops, engineering *and science* teams from various space agencies  need
> to  integrate their data in a*n* archive *or a set of federated archives,* and
> update/retrieve from *them, both during the mission lifetime, and in
> long-term archives post-mission.*
>
> Agreed common data formats (data standard), agreements on metadata
> content, *compliance with long-term digital preservation practices, such
> as CCSDS standards for OAIS, PAIS and future protocol-level standards yet
> to be developed by CCSDS.  *
>
>
>
>
>
>
>
> There are several problems with the original right hand side:
>
> a)       Agreeing formats is not adequate. For example the agencies could
> agree to use CSV – but what do the elements mean? what are the units? Is
> agency X going to combine something measured in meters with something
> measured in feet? In other words what metadata content is needed? This is
> what DAI is concerned with.
>
> b)      If Agency X wants the data from Agency Y after Y’s project has
> ended, can one be sure that the right metadata has been collected?
> MOIMS-DAI is working on “INFORMATION PREPARATION TO ENABLE LONG TERM USE”
> to create a checklist to help ensure that enough of the right kinds of
> metadata is collected. Of course ensuring the data continues to be usable
> despite the inevitable changes over time in software, systems, semantics
> etc., is covered by CCSDS 650.0-M-2, Reference Model for an Open Archival
> Information System (OAIS). Magenta Book. Issue 2. June 2012.
>
>
>
>
>
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