WORLD METEOROLOGICAL ORGANIZATION
INTER-PROGRAMME EXPERT TEAM ON METADATA AND DATA INTEROPERABILITY
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42
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CONTENTS
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Agenda |
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Executive
summary |
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General
summary of the work of the session |
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Annexes |
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AGENDA
1. ORGANIZATION OF THE SESSION
2. WMO CORE PROFILE OF THE ISO METADATA STANDARD
2.1 Review of the version 1.1 of the WMO core
profile
2.1.2 Clarification required for
the implementation of the WMO core profile by WIS centres
- File naming
conventions
- Metadata identifiers
- Relating data-files
to metadata-files
- Metadata versioning
- Dataset hierarchies
- Geographic metadata conventions &
machine-readable gazetteer for Volume A
- Human readable metadata & SRU query response
- Controlled vocabularies and ontologies
- Definition of access control policy controlled
vocabulary & implementation in metadata
record
- Miscellaneous metadata conventions
- Metadata management policies
- Metadata standards maintenance
4.1 Actions arising from this
meeting
4.2 Tooling to support
collaborative development of WMO Core Profile standard
___________
The first meeting of the CBS Inter-Programme
Expert Team on Metadata and Data Interoperability (IPET-MDI) was held in
Geneva, Switzerland, from 27 to 29 April 2010 under the chairmanship of Mr J.
Tandy (UK).
The meeting focused its activities on the WMO
core profile of the ISO metadata standard, in particular on the clarification
required for the implementation of the WMO core profile by WIS centres and the
tool to support the development of WMO Core Profile standard. The meeting
developed 62 recommendations in this respect related to the following items:
- File naming conventions
- Metadata identifiers
- Relating data-files to metadata-files
- Metadata versioning
- Dataset hierarchies
- Geographic metadata conventions & machine-readable gazetteer for Volume A
- Automated validation
- Human readable metadata & SRU query response
- Controlled vocabularies and ontologies
- Definition of access control policy controlled vocabulary & implementation in metadata record
- Miscellaneous metadata conventions
- Metadata management policies
- Tooling to support collaborative development of WMO Core Profile standard
The recommendations of the meeting will be
submitted to the meeting of the OPAG-ISS Implementation Coordination Meeting on
ISS (ICT-ISS) scheduled in Geneva from 27 to 30 September 2010.
The
documents prepared for the meeting are available from: http://www.wmo.int/pages/prog/www/WDM/IPET-MDI-I/IPET-MDI-I_list_documents.html
1. ORGANIZATION OF THE SESSION
1.1.1 The first meeting of the CBS
Inter-Programme Expert Team on Metadata and Data Interoperability (IPET-MDI)
was held in Geneva, Switzerland, from 27 to 29 April 2010 under the
chairmanship of Mr J. Tandy (UK). The list of participants is given in Annex to
this paragraph.
1.1.2 On behalf of the Secretary-General, Mr
P. Shi, Director of the WIS Branch, welcomed the participants. He
recalled that the fourteenth session of the Commission for Basic Systems
endorsed the version 1.1 of the WMO core profile of the ISO Metadata standard.
Version 1.1 is being implemented by the centres that are candidates to become
Global Information System Centres (GISC) or Data Collection or Production
Centres (DCPC). Those centres raised issues concerning the implementation of
the version 1.1. The sixth session of the Inter-Commission Coordination Group
on WIS, which was held in Seoul in February 2010, invited the IPET-MDI to
provide guidance on metadata for authors, including samples and templates, and
to define clear specification of minimum metadata requirements. Mr P. Shi
stressed the importance of considering the inclusion of this set of guidance in
a guide for the implementation of the WMO core profile.
1.1.3 The Commission agreed that the
application of the ISO 19100 series of geographic information standards to the
development of a WMO conceptual model of data representation should be
considered as a fundamental element of a CBS policy on data representation
systems. Applying a standard approach for data representation, this should lead
to the development of a WMO core profile of the ISO 19100 series for metadata
and data, encompassing the WMO core profile of the ISO metadata standard. CBS
tasked the IPET-MDI to develop and maintain a WMO conceptual data model and a
WMO core profile of the ISO 19100 series of standards for metadata and data.
1.1.4 CBS agreed that WMO and CBS would
benefit from closer cooperation with the Open Geospatial Consortium (OGC),
which sets standards for web access to geospatial information. A Memorandum of
Understanding between WMO and OGC was signed in November 2009.The WMO/OGC
Memorandum of Understanding is instrumental in providing the mechanism for the
co-ordination between the activities carried out by OGC and WMO with a view to
developing the use of ISO/OGC standards for the WIS. Mr P. Shi invited the
meeting to consider how to benefit from this MoU to facilitate the development
of a WMO conceptual data model and a WMO core profile of the ISO 19100 series
for metadata and data.
The participants of the meeting
agreed that development of the guidance for the WMO Core Profile metadata
standard. Due to time constraints the item "DEVELOPMENT OF A WMO CONCEPTUAL DATA MODEL" was removed from
the agenda. The modified agenda was adopted by the participants. It is
reproduced at the beginning of this report.
The meeting agreed upon its
working hours. The documents prepared for the meeting are available from http://www.wmo.int/pages/prog/www/WDM/IPET-MDI-I/IPET-MDI-I_list_documents.html.
2. WMO
CORE PROFILE OF THE ISO
METADATA STANDARD
2.1 Review
of the version 1.1 of
the WMO core profile
2.1.1.1 The meeting agreed on the editorial
corrections to the UML representation of the version 1.1 of the WMO core
profile of the ISO metadata standard as given in IPET-MDI-I/Doc. 2.1 (1) with a
view to aligning it to the Annex A to ISO 19115 Cor
1, and to publish the corrected version. The version number for this amended
release is discussed in item "2.1.2.58 Versions and future update
cycles". As these are ONLY correcting typos in WMO Core Profile
documentation, there is no need to reflect any changes in schema etc. Only the
UML descriptive document needs updating. Noting that these editorial
corrections had no impacts on the implementation of the WMO core profile, the
meeting recommended inviting the chair of the OPA-ISS and the President of CBS
to request the Secretariat to post this corrected version in http://wis.wmo.int/2010/metadata/version_1-1-1
together with the current extensions to ISO code lists.
2.1.1.2 Additional constraints identified during
this meeting will be expressed within the UML, therefore the standard profile
documentation must be updated. A schematron rule set will be derived from these
UML constraints. Guidance notes will be provided explaining more about the
impact of the constraints. To ensure completeness, conditions and notations on
usage will be added to the data-dictionary where appropriate to supplement the
UML model.
2.1.2 Clarification
required for the implementation of the WMO core profile by WIS centres
2.1.2.0 This section has notes regarding the usage
of ISO MI_Metadata and MD_Metadata root elements and the use or non-use of namespace
prefixes in examples in this document. The elements mentioned above are
both valid root elements in ISO19115-2. MD_Metadata is the current WMO
practice, and as such, sections that address elements in current practice use
the MD_Metadata as the root element. A
transition to using the MI_Metadata element as the
recommended root element is envisioned, so in this document examples that
illustrate future practice that will require MI_Metadata as the root element will
use that element. In future practice MI_Metadata will replace all usage
of MD_Metadata. Section 2.1.2.39
has more details about this transition.
Similarly, examples in
this document sometimes use the gmd prefix for
elements that are shown with default namespace in other examples. Users
of this document should understand that current WMO practice uses default
namespaces, but in the future it will be recommended that WMO XML use an
explicitly named prefix (gmd). For a given XML
document one method or the other must be chosen as is documented in section
2.1.2.43.
2.1.2.1 The meeting noted the following concerns
relating to the ‘file naming convention, identifier & uniqueness’ issue.
This issue has been obscured by continually entangling several problems:
·
The granularity
level described by each metadata record;
·
The need to accommodate a simple solution for GTS datasets intended for global exchange; and
· The association of metadata files
and data-files (or groups of data-files)
2.1.2.2 To illustrate the problem, the team
discussed two cases:
A. Metadata record A describes a dataset of bulletins
which are stored in the 24-hour cache of the GISC. The metadata record is
equivalent (although more informative) to a record in WMO vol
C1 & describes the normal
contents of this type of bulletin; for example SYNOPS from several observation
stations; including MLO (Mauna Loa, Hawaii).
B. Metadata record B describes a long-term climate record from station MLO
which is comprised of a collection of SYNOPTIC observations from, say, 1954.
2.1.2.3 Whilst both datasets are continually
changing, both metadata records are ‘quasi-static’; only needing to be changed
when the observation regime changes (i.e. a new instrument is deployed or the
exact observation location changes) The critical differences between records A & B in this example are:
·
Temporal extent: A
has a relative temporal extent in any
24-hour period, whilst B has
a temporal extent from 1954 to (almost) present day;
·
Citation authority: authority for A is int.wmo.wis,
whilst B is gov.noaa
· Quality control: the
dataset described by B may
have undergone additional quality control to validate the observation record
for inclusion in a long-term archive
2.1.2.4 Whilst the meeting noted that there may be significant overlap between A and B, one cannot assume that overlap exists. The meeting concluded that metadata records A
and B describe entirely different products!
2.1.2.5 The meeting noted that for efficiency, some
Regional Transportation Hubs (RTH) ‘batch’ bulletins into groups (a.k.a. messages) for efficient transfer. This
is not evident to the end users, hence the
content of a transport-level GTS message is not required to be described by a
metadata record. The meeting assumed that the user/consumer is interested
in the discrete bulletins which are currently catalogued in Volume C1 and will
be exposed via the WIS Discovery Access and Retrieval (DAR)-metadata catalogue.
2.1.2.6 Significant discussion about the file-naming-convention (see Attachment
II-15 to the Manual on the GTS) lead to the following statements:
·
All files (not bulletins)
exchanged via the GTS must conform
to this convention.
o
There are two types of data transfer in the GTS: file
transfer and legacy bulletin. Legacy bulletins are solely identified by
their abbreviated heading line (AHL), not by the filename of their transfer
container (a.k.a. message) file.
·
Whilst OAI-PMH has been agreed as the protocol for GISC-GISC
metadata harvesting, the WIS functional architecture indicates that the default mechanism for National Centres
(NC) and DCPCs to pass their metadata records to their affiliated GISC is via
sending of files. The meeting noted that the Internet connectivity is not
always available and transfer via GTS is necessary in such case.
o
Therefore, filenames
of all metadata files transferred via the GTS must conform to the endorsed
file-naming-convention.
·
The file-naming-convention is summarized as:
«productPart»_«originatorPart»_«YYYYMMDDhhmmss»[_«additionalPart»].«type».[«compression»]
o
where «productPart» is «pflag»_«productidentifier»,
and «pflag» describes the format of «productidentifier»,
o
«originatorPart» is C_«CCCC»,
where «CCCC» is 4-letter code for the
originating telecommunications centre, and
o
«type» is general format type from fixed acceptable list.
·
There are four types of «productPart» (hence values of «pflag») defined:
o
T_«TTAAii» and A_«TTAAii»«CCCC»«YYGGgg»[«BBB»] are provided for mapping bulletins
into file transfer. The latter (A_
form) gives all AHL information, while the former (T_ form) is sufficient for bulletins not using «BBB» for amendment/correction (ex. NWP
output). «YYGGgg»
is day-in-month, hour, and minute in UTC.
o
Routing of bulletins between RTHs is specified using «TTAAii» and «CCCC».
o
The file-naming-convention is designed in order to resolve
the limitations of too narrow namespace «TTAAii»,
and following two «pflag»s are
prepared for that purpose.
o
W_«WMO Product Identifier» is globally unique identifier of the
product, where «WMO Product Identifier»
is a comma-separated list of data properties, including originating centre,
data category, and other information, optionally followed by varying date and «BBB». Invariant string is intended
to be used in routing control.
Note 1: W_«WMO Product Identifier» scheme employs commas (,) to separate
elements – this may create problems
if these file-names are ever integrated into other lists or URLs as the comma
is commonly used as a list delimiter in software systems. ET-CTS should be
informed of this concern.
o
Z_«local product identifier» is a effectively a free-form identifier
type, which is unique only within the originating centre.
·
Eventually bulletins and T_ and A_
product-identifiers will be phased out in favour of file transfer with W_ and Z_ identifiers. However, currently Volume C1 and the Routing
Catalogue only covers bulletins,
which have to be mapped to either T_
or A_ types of filename.
· Implementation note:
within their GISC implementation, CMA have only accounted for T_ and A_ product identifier types.
2.1.2.7 As a DAR metadata record is considered to
be quasi-static (i.e. it is unlikely to change over the period of days or
months) certain instance-specific elements of the data-filename must be
excluded from the name of any associated metadata-identifier. For example, an
‘A_’ type product-identifier ‘«TTAAii»«CCCC»«YYGGgg»[«BBB»]’
would be truncated to ‘«TTAAii»«CCCC»’ to provide a unique identifier that does
not vary over time.
Separate metadata records for
amendments / corrections are considered unnecessary: the «BBB» element should
never be present in a metadata filename.
When amended to remove the
elements that may vary between bulletin instances, A_ product identifiers
differ in content from T_ product identifiers only by including «CCCC». Noting
that «CCCC» is also incorporated in the top-level file-naming convention, there
appears to be no value in using A_ product identifier types for metadata; T_
product identifier types should suffice.
W_ and Z_ product identifiers
should retain their arbitrary complexity, albeit amended to remove elements
that vary between bulletin/product instances (if necessary).
Given the nature of W_ and Z_
product-identifier schemes, the team were unable to see a mechanism for
establishing an implicit machine-interpretable linkage between a metadata and
its associated data files.
The meeting agreed to use suffix
".xml" instead of ".met" for compatibility with common
implementations (cf. 2.1.2.12).
Recommendation 1:
when metadata file is transferred between WIS centres, the metadata filenames:
- must comply with the WMO
file-naming-convention;
- should use T_ product identifiers in place
of A_ product identifiers to aid simplicity
- should truncate W_ product identifiers to
form an invariant string; i.e. the date and amendment / correction code will be
excluded
- must ensure that Z_ product identifier are
globally unique within the WIS
- must use the «YYYYMMDDhhmmss» element from the top-level file-naming convention to express the
metadata publication / update date-time (this must represent the same date-time
as the MD_Metadata/dateStamp element);
- Use an ‘.xml’ extension:
- Examples:
- T_FCUK31_C_EGRR_20100310180000.xml
- T_HHXA05_C_BABJ_20100427083000.xml
- W_FR-meteofrance-toulouse,GRIB,ARPEGE-75N10N-60W65E_C_LFPW_20100428115800.xml
2.1.2.8 Where metadata records are harvested from
contributors outside the WIS community using OAI-PMH, there is no way for the
harvester to know file naming conventions used by the metadata provider.
Therefore, in this situation, there is no requirement to constrain the
filename. Only where metadata records are transferred via the GTS or
other GTS-like file-transfer mechanisms do the filenames need to conform with
the convention above.
XML formats are not currently
used to transfer data via the GTS. However, once this changes, it is
conceivable to have collisions between data-files and metadata files. To
remedy this, there is a need to be able to distinguish between the files with
additional information in the filename.
Note 2: The ‘.xml’ file extension does not currently
appear in the permitted list in the file-naming convention. A proposal to
modify the file-naming convention is offered to ET_CTS & ET_OI:
Allocate a new extension=”.iso19139.xml”
2.1.2.9 Metadata identifiers do not need to
explicitly match (a truncated version of) the data-filenames they describe. The
team identified that the metadata naming conventions from IPET-MI-II (Moscow,
2006) could be applied [in principle].
Recommendation 2:
gmd:MD_Metadata/gmd:fileIdentifier is a URI (Universal Resource Identifier) structured as follows:
- fixed string "urn:x-wmo:md:"
- citation authority
- Examples:
§
"int.wmo.wis"
§
"gov.noaa"
§
"edu.ucar.ncar"
§
"uk.gov.metoffice"
- Citation
authority "int.wmo.wis" is used for all
datasets intended for global exchange
- Citation
authority for other datasets remains with the dataset provider, expressed using
a reverse-DNS name
- Register of
citation authorities should be maintained by WMO secretariat
- separator colon ‘:’
- empty string, reserved for future extension
- separator colon ‘:’
- unique identifier:
- if
a GTS «TTAAii» and «CCCC» is allocated for the
product use «TTAAii»«CCCC»;
- else
if a WMO Product Identifier is allocated for the product use a truncated WMO product identifier field
of the associated data-files, excluding the date-stamp and any other varying
elements as necessary; or
- else
use a locally-unique identifier for the citation authority (not recommended for
data and products intended for global exchange)
Examples:
- urn:x-wmo:md:int.wmo.wis::FCUK31EGRR
- urn:x-wmo:md:cn.gov.cma::NMC.NWP.HCXA05BABJ
- urn:x-wmo:md:int.wmo.wis::FR-meteofrance-toulouse,GRIB,ARPEGE-75N10N-60W65E_C_LFPW
[Action
MDI-1-i : Ted - propose mechanism for unique identification of place names -
e.g. urn:x-wmo:place:int.wmo.wis::AtlanticOcean
etc.]
The meeting noted that some
additional guidance may be necessary to facilitate the construction of WMO
product identifiers.
The meeting noted with
appreciation the WMO Product Identifier syntax adopted by the Satellite
community for RARS data and encouraged similar harmonization efforts for other
communities and data types.
The GTS Manual recommends using
BUFR/CREX Common Code Table C13 categories as data designators in WMO Product
Identifiers, although exactly how these categories are integrated deserves
further specification. The meeting noted the abbreviated categories proposed to
this end in the joint
ICM-MTN & ET-OI report for every data categories and sub-categories in
BUFR/CREX common code table C13, but saw the need for further refinement and a
formal approval as an extension to table C13
Recommendation 3:
gmd:MD_Metadata/gmd:fileIdentifier elements are treated as CASE-INSENSITIVE when
assessing metadata records for duplication.
2.1.2.10 The meeting noted that:
·
OAI-PMH requires the identifier must comply with generic URI
syntax (RFC2396, now obsoleted by RFC3986). The
naming convention defined in Recommendation 2 above is compliant to URN scheme
of URI. The namespace identifier of URN (i.e. "x-wmo") begins with "x-",
which indicates an experimental namespace not registered to IANA (cf.
RFC3406). In the long term, the WIS community may wish to apply to IANA
for registration of formal namespace "wmo"
under URN, or namespace under "info:" URI scheme if the review
process for URN does not work
(http://info-uri.info/registry/docs/misc/faq.html#use_urn describes such high
burden).
· OGC & others are
beginning to favour persistent URLs over URNs as they
are resolvable; an example would be: "cma.gov.cn/md/HCXA20BABJ.NMC.NWP"
2.1.2.11 Modifying the MD_Metadata/fileIdentifier may cause issues with
harvesting processes used by systems such as geonetwork. The gmd:MD_Metadata/gmd:fileIdentifier is used as a primary key
to identify records for harvesting. Changing the primary key may result in the
record appearing twice. To avoid needing to change
the identifier dynamically during
harvest, it is envisaged that the addition of a WMO Core Profile compliant
identifier will be added by bi-lateral arrangement a priori. Also, data
custodians may choose to create new
metadata records specifically for the WIS community. However, OAI servers do
not distinguish between metadata catalogues during harvesting; the entire
catalogue is open to all. Existing OAI servers are not currently set up to
expose only a subset of their catalogue. To resolve this concern, if the
data-provider is able to guarantee global uniqueness of their original MD_Metadata/fileIdentifier this will remain
acceptable as a primary key within WIS and there is no requirement to add a WMO
Core Profile compliant identifier.
Recommendation 4: WIS Centers should not modify MD_Metadata/fileIdentifer
(as well as any other content) when receiving metadata from external data
provider, as far as they guarantee global uniqueness of the fileIdentifier.
UUID (Universal Unique Identifier) is considered globally unique in this
respect. However, a WIS Center may
agree with the data provider to give a fileIdentifier
compliant to the WMO Core Profile. In that case previously given fileIdentifier is preserved in:
"MD_Metadata/dataQualityInfo/DQ_DataQuality/lineage/LI_Lineage/source/LI_Source/sourceCitation/CI_Citation/identifier/MD_Identifier/code".
It
is possible that future versions of ISO 19115 will allow multiple
identifications in a single metadata record. If this becomes part of the
standard an alternative convention may be developed. Note that renaming
of fileIdentifier shall not apply when GISC is relaying
GISC-to-GISC synchronisations, in order to avoid looping.
The minimum required information
for a sourceIdentifier is:
<gmd:dataQualityInfo>
<gmd:DQ_DataQuality>
<gmd:scope>
<gmd:DQ_Scope>
<gmd:level>
<gmd:MD_ScopeCode
codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#MD_ScopeCode" codeListValue="dataset">dataset</gmd:MD_ScopeCode>
</gmd:level>
</gmd:DQ_Scope>
</gmd:scope>
<gmd:lineage>
<gmd:LI_Lineage>
<gmd:source>
<gmd:LI_Source>
<gmd:sourceCitation>
<gmd:CI_Citation>
<gmd:title>
<gco:CharacterString>This is the title of the original
dataset</gco:CharacterString>
</gmd:title>
<gmd:date>
<gmd:CI_Date>
<gmd:date>
<gco:DateTime>2010-05-08T07:38:00</gco:DateTime>
</gmd:date>
<gmd:dateType>
<gmd:CI_DateTypeCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_DateTypeCode" codeListValue="creation">creation</gmd:CI_DateTypeCode>
</gmd:dateType>
</gmd:CI_Date>
</gmd:date>
<gmd:identifier>
<gmd:MD_Identifier>
<gmd:code>
<gco:CharacterString>This is the identifier</gco:CharacterString>
</gmd:code>
</gmd:MD_Identifier>
</gmd:identifier>
</gmd:CI_Citation>
</gmd:sourceCitation>
</gmd:LI_Source>
</gmd:source>
</gmd:LI_Lineage>
</gmd:lineage>
</gmd:DQ_DataQuality>
</gmd:dataQualityInfo>
The meeting noted that
ISO 19115 is under revision process, by which MD_Metadata/gmd:fileIdentifier will be obsoleted by alternative notation that allows multiple
identification information. After that takes place, it might be less
confusing than "changing" fileIdentifier
that a WIS Centre "adds" second file identifier compliant to WMO Core
Profile. But careful consideration on synchronization and metadata
ownership is required.
Note 3: ISO19115 Revision team should be informed of
our need to use multiple MD_Metadata/fileIdentifier
elements
2.1.2.12 The meeting noted that contrary to previous
understanding, the common OAI implementation do permit the file-name and identifier of a metadata record to be
different. However, it appears that both GEONETWORK and jOAI
both require the filename to have a
‘.xml’ extension.
2.1.2.13 The relationship between a given metadata
identifier and the names of the group of data-files it describes cannot be
routinely inferred from the MD_Metadata/fileIdentifier element or metadata
filename.
Recommendation 5: where possible, the metadata identifier
should map onto the invariant elements of the data-filename to help a human
reader infer the connection. An explicit machine-interpretable linkage to the
associated data-files will be expressed within the metadata record itself using
the
MD_Metadata/gmd:describes/gmx:MX_DataSet/gmx:dataFile/gmx:MX_DataFile/gmx:fileName
element with regular expression of filename as
content. Additional mandatory elements are: fileDescription
and fileType
2.1.2.14 The meeting agreed that there appears to be
no requirement for a machine-interpretable linkage at the file-name level; the
metadata record will not be employed
to resolve routing information for the GTS, so speed & robustness of GTS message-switching
will be unaffected. However, for efficiency, a GISC node may choose to maintain an external mapping of metadata identifiers
to associated filename expressions enabling quick look-up on ingest of new
data-files for indexing to the associated metadata file. In order to ensure
consistency across all GISC nodes, all datasets intended for global exchange
must employ the same mechanism to define the explicit machine-interpretable
linkage from metadata record to data-files. Other datasets are free to choose
their own schemes or employ local agreements as these links need only be
resolved at the NC or DCPC.
Recommendation 6: where the citation authority is int.wmo.wis
(signifying a dataset intended for global exchange), a standardized regular
expression syntax will be used to express the linkage between the metadata
record and the associated data-files via the
MD_Metadata/gmd:describes/gmx:MX_DataSet/gmx:dataFile/gmx:MX_DataFile/gmx:fileName
element.
Multiple linkages may be expressed using the OR syntax in regular expression ‘|’.
Examples:
- Data-filename instance:
“A_SMCI01BABJ281200_C_BABJ_20100428120000.txt”
- MD_Metadata/fileIdentifier=”urn:x-wmo:md:int.wmo.wis::SMCI01BABJ”
- MD_Metadata/gmd:describes/gmx:MX_DataSet/gmx:dataFile/gmx:MX_DataFile/gmx:fileName=”/^A_
SMIC01BABJ[0-9]+_C_BABJ_[0-9]+\.txt$/”
- MD_Metadata/gmd:describes/gmx:MX_DataSet/gmx:dataFile/gmx:MX_DataFile/gmx:fileDescription=”General
description of the datafile”
- MD_Metadata/gmd:describes/gmx:MX_DataSet/gmx:dataFile/gmx:MX_DataFile/gmx:fileType=”text/plain”
- Data-filename instance:
“W_FR-meteofrance-toulouse,GRIB,ARPEGE-75N10N-60W65E_C_LFPW_
20061001000000.bin”
- MD_Metadata/fileIdentifier=”urn:x-wmo:md:int.wmo.wis::FR-meteofrance-toulouse,GRIB,ARPEGE-75N10N-
60W65E_C_LFPW”
- MD_Metadata/gmd:describes/gmx:MX_DataSet/gmx:dataFile/gmx:MX_DataFile/gmx:fileName=”/^W_FR-
meteofrance-toulouse,GRIB,ARPEGE-75N10N-60W65E_C_LFPW_[0-9]{14}\.bin$/”
- MD_Metadata/gmd:describes/gmx:MX_DataSet/gmx:dataFile/gmx:MX_DataFile/gmx:fileDescription=”General
description of the datafile”
- MD_Metadata/gmd:describes/gmx:MX_DataSet/gmx:dataFile/gmx:MX_DataFile/gmx:fileType=”application/
octet-stream”
No serious issues are likely to
arise from use of regular expressions on GTS filenames as the character set is
limited to International Alphabet 5. Further information on Regular
Expressions can be found
at http://docs.google.com/View?id=df4kmgqs_50ffmzmqgj.
The summary is:
·
Metadata creator or manager should provide regular
expression that is understandable for all GISCs. Recommended syntax is
chosen from common subset of various implementations (cf. above reference for
detail; syntax letters are ? * + {,} (|)
^ $ [] [^] [a-z] \d \w . \. \+).
·
GISC Cache should support at least recommended syntax.
It may also support other metacharacter for further
development, but it must not alter recommended syntax and its semantics.
It is advised to check regular expression provided in metadata before matching.
·
Although WMO Filename Convention is case-insensitive,
metadata creators should give regular expression in correct case of
letters. For example, location identifier should be described as [A-Z]{4}, not [a-z]{4}.
· GISC Cache should use
"ignore-case" option of regular expression library in matching
metadata and dataset fragment.
Above recommendations should be
reviewed when use of the regular expression is extended beyond current GTS
files and bulletins, or WIS data or products intended for global exchange is
extended beyond current GTS.
2.1.2.15 The team was asked to verify the agreement
made at the ICG-WIS 6 indicating that only
the fileIdentifier element and metadata creation
date-time stamps will be used to assess uniqueness / duplication of a given
metadata record compared to other records.The
sequence (time-order) of metadata files with the same fileIdentifier
will be assessed according to the date-time stamp.
Recommendation 7:
WIS implementers will assess the uniqueness of a metadata record using only the
fileIdentifier element and metadata creation
date-time stamps:
gmd:MD_Metadata/gmd:fileIdentifier
gmd:MD_Metadata/gmd:dateStamp
Version
numbering or date-stamps are explicitly forbidden from the fileIdentifier
element. The MD_Metadata/dateStamp is the correct place for this information. It
may also optionally appear in the metadata filename (see below). Changing the fileIdentifier element in any way
will appear to be a new product!
Note to
implementers: The gmd:dateStamp within the metadata record should be distinguished from the datestamp in OAI-PMH wrapper XML, which appears as oai:header/oai:datestamp. Note that the OAI-PMH Implementation
Guideline mandates that the OAI-PMH
Aggregators (i.e. a WIS Center that provides metadata harvested from somewhere
else) must use local harvesting time as oai:datestamp.
In other words, OAI-PMH providers of GISCs and RTH-type of DCPCs must not use gmd:dateStamp as oai:datestamp,
because connected GISC cannot use incremental harvesting from such
provider. In some implementations the timestamp of metadata files are
given as oai:datestamp, and the operator can cause
re-synchronization by changing metadata file time stamps (such as touch(1)
command). This is intended behavior, and
developers should follow this methodology so as not to disable this
functionality.
2.1.2.16 Fundamental to ISO19115 are the concepts of
dataset (DS_DataSet) and aggregations (DS_Aggregate). Aggregations, or collections, of datasets
can be of many types including series,
platforms & sensors etc. Every type
of aggregation can include subsets and/or discrete datasets. The relationships
permitted within the ISO19115 conceptual model allow one to create a hierarchy of related aggregations and
datasets. This enables data providers to structure their metadata for improved
clarity & browsing. Both datasets and aggregations have associated metadata
(MI_Metadata). It is implied that
metadata records describing a given aggregation or dataset within the hierarchy
inherit content from their parent metadata record, only amending as
necessary. Additionally, the MD_AggregateInformation element of a specific
metadata record provides a mechanism to associate the subject dataset with
another related dataset. In this case (crossReference
or largerWorkCitation instead of direct hierarchy),
there is no implied inheritance. These mechanisms allow one to create a hierarchy that enables a data-consumer
to browse between related dataset
descriptions.
2.1.2.17 NCAR’s Community
Data Portal, the THREDDS (Thematic Realtime
Environmental Distributed Data Services Project and NOAA’s
National Geophysical Data Centre [http://www.ngdc.noaa.gov/]
have gained experience from structuring datasets within hierarchies. These
dataset hierarchies can be used to structure a browsable network of related
datasets. Such browsable networks can be used to supplement
other browse-hierarchies inferred from the categorization of metadata records
using structured taxonomies etc. (see below). Reference information can be
found at http://www.unidata.ucar.edu/projects/THREDDS
2.1.2.18 NOAA-NGDC are also developing experience in decomposing their catalogue of metadata
records into re-usable elements explicitly identified using UUIDs
and resolvable at a specified URL. Each metadata record uses xlink to reference
the metadata component for inclusion. This normalization
of metadata records aids maintenance by minimizing redundant information. NGDC
respond to consumer queries with either fully-resolved & complete metadata
records (from a web-accessible folder) or partially complete metadata records
containing the xlinks which reference the missing
elements. Both are valid depending on the needs of the consumer.
2.1.2.19 Referring to the needs of WIS, the main focus
is to enable the discovery of
datasets. Building a browse-hierarchy from a network of related metadata
records will add value in the long-term. However, this does not offset the
additional complexity & risk of implementation during the development-phase
of the WIS.
Recommendation 8:
Following creation and subsequent validation of the DRAFT metadata records to
populate the initial WIS DAR catalogue, IPET-MDI will identify candidate static metadata components (i.e. CI_ResponsibleParty object describing WMO) that could be
referenced via xLink from the discovery metadata
records.
[Action
MDI-1-ii: Jean Pierre - Develop candidate static
metadata components]
Such static metadata components
will be identified by UUID and resolvable by URL. These metadata components will be hosted at wis.wmo.int/.
Recommendation 9:
in order to maintain simple GISC implementation, discrete metadata records will
be used to describe GTS products intended for global exchange. Multi-level
dataset-hierarchies may be used to describe datasets resolved at the DCPC and
NC levels.
Recommendation 10:
metadata records describing GTS products intended for global exchange will
continue the practices established to populate Vol C1
where each metadata record describes a set of data-products that vary only with
time. Once a particular dataset has been discovered, GISC nodes are only
required to offer a query service that allows sub-querying based on time. This
will require significant numbers of fine-grained
metadata to be created and published in order to retain simplicity of operation
at the GISC-nodes.
Recommendation 11:
DCPCs and NCs may choose to describe
their dataset at whichever level in the ‘hierarchy’ is deemed appropriate. For
example, a single TIGGE metadata record may describe 10000 data-files or more,
thus avoiding the need to create many hundreds or thousands of metadata
records. In this case, the onlineResource is likely
to refer to a more sophisticated service that facilities query by multiple
parameters in order to minimize the number of positive results returned for a given
query.
[Action
MDI-1-iii: Manuel – build dataset examples for TIGGE]
Recommendation
12: IPET-MDI develops best practice for creating and maintaining hierarchies of
related datasets.
2.1.2.20 As implementation experience with WIS
increases, IPET-MDI will continue to review the value of structured
dataset-hierarchies against the potential cost & risk of implementation.
This may lead to updated
recommendations that positively endorse the use of dataset-hierarchies for
DCPCs or NCs dataset aggregations and perhaps even products intended for global
exchange served by the GISCs. These recommendations imply that NMHSs such as
JMA will be required to create and maintain many thousands of metadata records
to describe their GRIB bulletins (approx. 21000 products). It is recognized
that the query service at the GISC is likely to return large numbers of
positive hits to any query for JMA GRIB data, which is not particularly helpful
for the user. However, there is nothing to stop JMA from exposing a richer,
more sophisticated service interface(s) as a DCPC that provides higher levels
of control to the user. These interfaces would likely be described by fewer, more coarse-grained metadata
records, thus returning fewer positive hits to an initial query in the DAR
catalogue. In this case, the user experience is likely to be significantly
improved.
2.1.2.21 The implementation experiences of DWD, CMA
and JMA had noted a divergence of approaches in the use of geographic metadata.
The WIS implementation community sought explicit guidance on this topic.
Recommendation 13: boundingBox
MD_Metadata/identificationInfo/MD_DataIdentification/extent/EX_Extent/geographicElement/EX_GeographicBoundingBox
will
be mandatory to ensure compliance with INSPIRE regulations. Where the sensor
platform is mobile (e.g. AMDAR, ships or bouys) the
bounding box will describe the maximum reasonable extent within which the
platform may operate, potentially a global extent. However, it should be noted
that GTS practices (tables C1, C2 & C3 of the Manual on GTS) keep the
extent of the bulletin fixed and
require that the data from mobile platforms is allocated to the appropriate
bulletin based on the location of the platform.
The team noted that specifying
datasets that include the north or south poles may be difficult. Also, best
practices on acceptable units for lat/lon must
provided (e.g. -180 to +180, -90 to +90; 0 to 360; or East/West notation.
Recommendation 14:
following best-practice developed by NGDC, boundingExtent,
boundingBoxExtent, boundingTemporalExtent,
and boundingVerticalExtent elements will be tagged for identification and easy
re-use within the metadata record:
<gmd:extent>
<gmd:EX_Extent id="boundingExtent">
...
<gmd:EX_GeographicBoundingBox id="boundingGeographicBoundingBox">
...
<gmd:EX_TemporalExtent id="boundingTemporalExtent">
...
<gmd:EX_VerticalExtent id="boundingVerticalExtent">
Recommendation
15: place-names (such as
observation stations and other static sensor platforms) will be expressed as
both keyword (type=place) and geographicIdentifiers:
·
MD_Metadata/identificationInfo/MD_DataIndentification/descriptiveKeywords/MD_Keywords/keyword
·
MD_Metadata/identificationInfo/MD_DataIndentification/descriptiveKeywords/MD_Keywords/type
= "place"
·
MD_Metadata/identificationInfo/MD_DataIdentification/extent/EX_Extent/geographicElement/EX_GeographicDescription/geographicIdentifier/MD_Identifier
Recommendation 16:
place-names used as keywords and geographicIdentifiers
will be defined in a register (or controlled vocabulary) based on the content
of Vol A. Each entry must have a UUID (as primary
key) in addition to the (mostly) unique WMO station-code identifier. The
station-gazetteer register & each entry will be resolvable by URL
(incorporating the UUID) and, as a minimum, validate the authenticity of a
given station.
The
Volume A gazeteer implementation will be available in
the form of a CT_CodelistCatalogue (e.g
http://asdd.ga.gov.au/asdd/profileinfo/anzlic-allgens.xml) that can be
referenced as: a keyword thesaurus
MD_Metadata/identificationInfo/MD_DataIdentification/descriptiveKeywords/MD_Keywords/thesaurusName/CI_Citation
or
as an authority in the geographicIdentifier case:
MD_Metadata/identificationInfo/MD_DataIdentification/gmd:extent/EX_Extent/geographicElement/EX_GeographicDescription/gmd:geographicIdentifier/MD_Identifier/authority/CI_Citation
In
the geographicIdentifier case, the code:
MD_Metadata/identificationInfo/MD_DataIdentification/extent/gmd:EX_Extent/geographicElement/EX_GeographicDescription/geographicIdentifier/MD_Identifier/authority/CI_Citation/identifier/MD_Identifier/code/CharacterString
shall
have the form:
http://wis.wmo.int/WMOVolumeAGazeteer.xml#WMOStationNumber.
The
CT_CodelistCatalogue includes a codeEntry
element for each item in the catalog. The codelistItem/CodeListDictionary/codeEntry/description shall include the
bounding box or location and elevation for the item in well-known text
(http://en.wikipedia.org/wiki/Well-known_text).
Note: If
the WMO Station Index refers to separate locations for surface and upper air
observations, the location shall be described as MULTIPOINTZ((LON1 LAT1 ELE1),(LON2 LAT2 ELE2)).
[Action
MDI-1-vi: Manuel & Jeremy (& Alexander Besprozvannykh?)
- develop simple Vol A gazetteer]
2.1.2.22 More sophisticated gazetteers are desirable
for future implementations, perhaps providing a Web Feature Service interface.
UK NERC has some experience of establishing sophisticated gazetteer services.
Also, Australian NODC have funding request in place (pending decision in June
2010) to set up a gazetteer service via 12-month project.
2.1.2.23 A set of conformance classes will be
establish for validating compliance of metadata records against the WMO Core
Profile. Each conformance class will vary in its scope of validation and will
have an associated conformance test that can be executed automatically.
Recommendation 17:
ISO19115 / ISO19139 compliance will be assessed for all metadata records
Candidate conformance tests for
‘vanilla’ ISO19115 include:
·
Validate against ISO19139 schema
·
Validate ISO19115 condition statements (schematron)
· Validate ISO19115
code-lists (schematron)
Recommendation 18:
metadata describing GTS products intended for global exchange must conform to
the WMO Core Profile metadata standard.
Recommendation 19:
metadata records from DCPCs and NCs should
employ the WMO Core Profile metadata standard. However, in order to be
inclusive of other data-provider communities, this is not mandatory. Compliance
with ISO19115 remains a mandatory requirement.
2.1.2.24 Candidate conformance tests for WMO
Core-Profile compliance include:
·
Validate WMO Core Profile extensions: condition statements
(schematron)
·
Validate WMO Core Profile extensions: code-lists - extending
to include thesauri, thematic hierarchies, keyword lists, station-gazetteer
(schematron)
· Validate Extension
metadata for WMO Core Profile
[Action
MDI-1-viii: Ted - define the WMO Core Profile extension object]
[Action
MDI-1-ix: Jeremy - define the full set of WMO Core Profile code-lists]
Recommendation 20:
WMO Core Profile compliance conformance tests will create warnings if a
deprecated practice is identified.
Recommendation 21:
a central repository of code-lists (etc.) must be established in order that the
schematron rule-sets can validate against an official source.
Recommendation 22:
unknown extensions to ISO19115/ISO19139 will be ignored unless (a) they
conflict with WMO Core Profile, or the extensions are sufficiently documented
in order to validate against (see below)
Recommendation 23:
Where WMO Core Profile metadata records include multiple language definitions,
validation will ensure that English definitions are present at a minimum.
2.1.2.25 Candidate conformance tests for validating other
ISO19115 profiles include:
·
Validate extension metadata
· Validate extensions as
directed by extension metadata; i.e. supplementary schema, constraints and codelists
[Action
MDI-1-xi: Jean Pierre with guidance from Greg & Ted - develop schematron
rule-sets to implement the conformance tests, using the geonetwork & ANZLIC
schematron rules as a baseline. The focus will be on validation against the WMO
profile. Developing validation tests against other profiles by interpretting
the ISO19115 extension record is a significantly lower priority]
Recommendation 24:
conformance tests (including schematron rule-sets) will be published via a
central repository
2.1.2.26 Schema validation tools commonly check for
the existence of elements rather than whether or not they have content. It was
noted that, in order to unambiguously identify empty elements, geonetwork
automatically adds a “nilReason” into a gco:characterString if it is empty.
Recommendation 25:
validation of metadata must occur when metadata is harvested from DCPC or NC
into the GISC catalogue. It is recommended (although not mandatory) that
metadata is validated when synchronized between GISC-nodes to protect against
inadvertent corruption during the harvesting process.
2.1.2.27 The response to a Z39.50 SRU query may
contain multiple ‘results’. Whilst a particular result may be described using the full WMO Core Profile or ISO19139,
efficiency suggests you only return a small subset of metadata for each.
Recommendation 26:
use Timo’s existing SRU response schema.
2.1.2.28 Both SRU response and full metadata records
must be human readable. In particular, to support Meteo
France in the development of baseline metadata records for the GISC catalogue,
a stylesheet must be provided that provides insightful guidance to the
reviewers of the draft records (they will not be metadata experts!) and allows
them to modify any mistakes in-situ. It was noted that ‘tool-tips’ (annotation
from the schema documents) may be incorporated in this guidance. It was also noted
that geonetwork’s “nested box” presentation format
was simple to understand, suggesting that the geonetwork stylesheet may be a
good starting place. NGDC have developed some sophisticated style-sheets that
offer in-line editing and FAQ-style interfaces. Also NCAR have developed a
'nested box' UI to display metadata and NetCDF header information.
[Action
MDI-1-xv: Eiji + Michael + Ashok +
Ted - develop a sophisticated stylesheet that provides guidance & in-line
editing capabilities to support validation of baseline metadata developed by Meteo France
(would this also provide a basic template for the minimum metadata footprint –
i.e. be able to create a new metadata record from scratch?)]
2.1.2.29 The user’s browse experience of the DAR
catalogue can be greatly improved by providing one or more hierarchies of
search terms. A user is able to browse these search terms in the knowledge that
they do not have to guess how
datasets have been categorized. Furthermore, these hierarchies can be used to
assist metadata authors categorize their datasets so that they are readily
discoverable. Particularly important is the thematic keyword taxonomy that is
used to categorize the dataset. The MD_TopicCategory object enumerates a fixed set of categories and
cannot be extended. Only a few values from MD_TopicCategoryCode are likely of interest
within the WMO Core Profile:
·
climatologyMeteorologyAtmosphere [TopicCatCd
004];
·
environment [TopicCatCd 007];
·
inlandWaters [TopicCatCd
012]; and
· oceans [TopicCatCd 014]
The WMO Core Profile requires
further domain-specific categorization of data.
Recommendation 27: domain-specific categorization of data will
be achieved using the
MD_Metadata/identificationInfo/MD_DataIdentification/descriptiveKeywords/MD_Keywords/keyword
element(s) (type
= theme).
2.1.2.30 The WMO Common Codes table C13 provides the
mandated categorization structures for WMO content. Table C13 is in the process
of having a set of short-names added to supplement to numeric classification.
This is currently incomplete, but it represents a creditable effort to
establish a structured taxonomy of keywords consistent with GTS practices.
[Action
MDI-1-xvi: Manuel + Simon - further develop the short-names for table C13]
Recommendation 28:
for consistency, each WMO Core Profile compliant metadata record will contain
at least one domain-specific categorization keyword from one of the following
taxonomies:
·
Nasa’s Global Change Master Directory (GCMD) [http://gcmd.nasa.gov/]
·
CF
convention standard names [http://cf-pcmdi.llnl.gov/documents/cf-standard-names/]
·
WMO Common
Codes table C13
·
WMO #182
International Meteorological Vocabulary *
[*enhanced by Jean Pierre
to a structured taxonomy: meeting document “IR4.JPA.v0.1.pdf” refers]
2.1.2.31 However, it was noted that the WMO
International Meteorological Vocabulary does not appear to be maintained or governed.
Note: maintenance
& governance of controlled vocabularies established by other commissions
must be agreed (issue to be passed to ICT-ISS).
2.1.2.32 Other candidate taxa
may be sourced from:
·
Earth System Curator [http://www.earthsystemcurator.org/]
·
ESMF (Earth System Model Framework) [http://www.cisl.ucar.edu/research/2005/esmf.jsp]
·
Metafor [http://metaforclimate.eu/]
[Action
MDI-1-xviii: Manuel + Michael + Jeremy - investigate the use of Protegé tools,
RDF/OWL & SKOS Simple Knowledge Organization System [http://www.w3.org/2004/02/skos/] to build hierarchical
taxonomies / simple ontologies from GCMD, CF standard names & WMO Common
Codes table C13. Note that NCAR's portal codebase now includes these technologies]
2.1.2.33 Other controlled vocabularies include:
·
GTS product priority type
·
Access control category code
·
MD_MaintenanceFrequencyCode *
· ...
Recommendation 29: *use
of bespoke extensions to the MD_MaintenanceFrequencyCode code-list will be prohibited. As an
alternative the following must be used:
- MD_Metadata/metadataMaintenance/MD_MaintenanceInformation/maintenanceAndUpdateFrequency = “continual”
- MD_Metadata/metadataMaintenance/MD_MaintenanceInformation/userDefinedMaintenanceFrequency = « ISO8801-compliant duration »
This applies to both data and
metadata maintenance. The example above is for metadata. For the reference, the
XPaths are:
·
MD_Metadata/identificationInfo/MD_DataIdentification/resourceMaintenance/MD_MaintenanceInformation/maintenanceAndUpdateFrequency
and
·
MD_Metadata/identificationInfo/MD_DataIdentification/resourceMaintenance/MD_MaintenanceInformation/userDefinedMaintenanceFrequency
2.1.2.34 Other Technical Commissions should provide
their keyword proposals based on their vocabularies and provide templates appropriate
to commission’s work.
Other Technical Commissions
should support such an activity by providing the crucial domain expertise and
may already have ontology activities.
2.1.2.35 Controlled vocabularies from other
commissions include:
·
Agriculture (c. Byong-Lyol Lee
[KMA - blleesnu@snu.ac.kr])
·
Atmospheric Science (c. Joerg Klausen [chair of ET-WDC & GAWSIS] & Geir Braathen [WMO Secretariat - gbraathen@wmo.int])
o
naming chemical compounds
o
analytical methods used in atmospheric composition
monitoring
o
physical principles used in atmospheric composition monitoring
·
Aeronautical
·
Hydrology
·
JCOMM (c. Greg Reed)
·
CF-NetCDF
Recommendation 30: multi-language implementations of code-lists
may be used.
[Action MDI-1-xx: Jeremy - add example of both
specification & use of multi-language code-list]
2.1.2.36 The subject here is the access constraints
for the target dataset.
Recommendation
31: candidate vocabulary terms for WIS access constraints include:
·
Unrestricted
·
Resolution
40 and Resolution 25 Essential Data
·
Resolution
40 and Resolution 25 Additional Data
·
Custom
2.1.2.37 Unrestricted
is semantically equivalent to Resolution 40 and Resolution 25 Essential Data.
Continuing current GTS practices
where RTHs are responsible for enforcing access control policies on behalf of
data-providers, GISCs will be responsible for enforcing the access control
policies cited in the metadata record for each product.
Recommendation 32: best practice suggests that the absence the useConstraints attribute:
MD_Metadata/identificationInfo/MD_Identification/resourceConstraints/MD_LegalConstraints/useConstraints
implies
Unrestricted. However, the Resolution 40 and Resolution 25 Essential
Data access control category should be used explicitly to indicate that
data-providers are sharing this dataset under WMO Resolution 40 or Resolution
25.
Recommendation 33:
the Custom access control category is
used to indicate access control that is defined by the data-provider. The
details of the policy must be referenced by URL.
Recommendation 34:
the access control policy will be defined in the following elements:
·
MD_Metadata/identificationInfo/MD_Identification/resourceConstraints/MD_LegalConstraints/useLimitation/gco:CharacterString = ”«category-code»”
·
MD_Metadata/identificationInfo/MD_Identification/resourceConstraints/MD_LegalConstraints/useConstraints/MD_RestrictionCode = ”otherRestrictions”
·
MD_Metadata/identificationInfo/MD_Identification/resourceConstraints/MD_LegalConstraints/otherConstraints/gco:CharacterString = ”«category-code»”
·
«category-code» will be a semi-controlled vocabulary
for the WMO Core Profile and can be either:
o
“WMO
Essential”
o
“WMO
Additional”
o
«free-text»
“otherRestrictions” is part of the codelist
MD_RestrictionCode
«free-text» is used to describe the custom access control policy and is
recommended to include the URL of a resource describing the access
control policy in detail.
If the access is NOT controlled (i.e.
unrestricted) the resourceConstraints element is
omitted.
2.1.2.38 Example from NOAA
Metadata
constraints (WMO probably has their own language...)
<gmd:metadataConstraints>
<gmd:MD_LegalConstraints>
<gmd:useLimitation>
<gco:CharacterString>While every effort has
been made to ensure that these data are accurate and reliable within the limits
of the current state of the art, NOAA cannot assume liability for any damages
caused by any errors or omissions in the data, nor as a result of the failure
of the data to function on a particular system. NOAA makes no warranty, expressed
or implied, nor does the fact of distribution constitute such a warranty.</gco:CharacterString>
</gmd:useLimitation>
</gmd:MD_LegalConstraints>
</gmd:metadataConstraints>
Maintenance note
<gmd:metadataMaintenance>
<gmd:MD_MaintenanceInformation>
<gmd:maintenanceAndUpdateFrequency gco:nilReason="Unknown"/>
<gmd:maintenanceNote>
<gco:CharacterString>This metadata was
automatically generated from the FGDC Conten
Standards for Digital Geospatial Metadatastandard
version FGDC-STD-001-1998.</gco:CharacterString>
</gmd:maintenanceNote>
</gmd:MD_MaintenanceInformation>
</gmd:metadataMaintenance>
Note: ISO19115:2012 revision is likely to add a
citation attribute that will enable the custom
access control policy to reference the details. Resolution 40 and Resolution 25
may also be cited using this mechanism.
2.1.2.39 Root elements for metadata files:
Recommendation 35:
the root element for each metadata record shall be MI_Metadata from ISO19115-2:2009. The selection of MI_Metadata as the
root elements permits inclusion of content from part 2 of the ISO geographic
metadata standard; namely the remote-sensing extensions.
The ISO19115-2 XML schema can be
found at
http://www.ngdc.noaa.gov/metadata/published/xsd/schema/gmi/
[Action
MDI-1-xxi: Ted - recommend best practice to enable transition from MD_Metadata
to MI_Metadata - including reference 'official'
schema location]
It is noted that the use of MI_Metadata as a root element will
have a detrimental effect on the ability of geonetwork to validate and consume
metadata records.
Recommendation 36:
the continued use of MD_Metadata as root
element will be permitted. However, validation rules in conformance tests will
be configured to flag this as a DEPRECATED practice. The validation warning
will recommend use of MI_Metadata.
Recommendation 37:
a single metadata file may contain a collection of metadata records. In this
case, the root element must be a concrete sub-class of DS_Aggregate.
2.1.2.40 Metadata standard name:
Recommendation 38:
MD_Metadata/metadataStandardName must always use the following text:
<gmd:metadataStandardName>
<gco:CharacterString>ISO
19115-2 Geographic information — Metadata — Part 2: Extensions for imagery and
gridded data</gco:CharacterString>
</gmd:metadataStandardName>
This text is the full
title of the ISO19115-2 geographic information metadata standard.
2.1.2.41 Metadata standard version:
Recommendation 39:
MD_Metadata/metadataStadardVersion must always use the following text:
<gmd:metadataStandardVersion>
<gco:CharacterString>ISO
19115-2:2009-02-15</gco:CharacterString>
</gmd:metadataStandardVersion>
This text is the standard
short-name used to identify the ISO19115-2 geographic information metadata
standard. Adherence to the WMO Core Profile is cited by the inclusion of an
appropriate
MD_Metadata/metadataExtensionInfo/MD_MetadataExtensionInformation object:
/gmi:MI_Metadata/gmd:metadataExtensionInfo/gmd:MD_MetadataExtensionInformation/gmd:extensionOnLineResource/gmd:CI_OnlineResource/gmd:name/gco:CharacterString
contains human-readable concise name
and version of the Profile, while
/gmi:MI_Metadata/gmd:metadataExtensionInfo/gmd:MD_MetadataExtensionInformation/gmd:extensionOnLineResource/gmd:CI_OnlineResource/gmd:linkage/gco:URL
contains machine-readable URL at
which metadata release package for that version is located.
2.1.2.42 File conventions:
Recommendation 40:
each metadata file must contain one, and only one, record. Valid root elements
are:
·
DS_Aggregate (implying
all concrete sub-classes)
·
MI_Metadata
·
MD_Metadata
[DEPRECATED]
Recommendation 41:
each metadata file must be comprised of well-formed XML. [http://www.w3.org/TR/REC-xml/#sec-well-formed]
Recommendation 42:
metadata files must be encoded in UTF-8 [RFC3626, http://en.wikipedia.org/wiki/UTF-8]
2.1.2.43 Use of Explicit Namespaces
Recommendation 43:
The use of a default namespace is currently customary in XML records and is an
acceptable construction in metadata XML for WIS.
Including
explicit namespace prefixes for
all elements in an XML record is the recommended and preferred practice in
metadata XML for WIS - but not mandatory. In this practice all namespaces
should be declared with a prefix and each element in the XML record should
explicitly include its namespace prefix.
Current Practice:
namespace
declaration (in the root element):
xmlns=http://www.isotc211.org/2005/gmd <!--Default
namespace declaration -->
example
element:
<identificationInfo> <!-- default namespace assumed
for element -->
Recommended Practice:
namespace declaration (in
the root element):
xmlns:gmd=http://www.isotc211.org/2005/gmd <!--Explicit namespace declaration -->
example element:
<gmd:identificationInfo> <!--namespace prefix included in element -->
[Action
MDI-1-xxii: Michael - add examples with agreed upon reference URLs for schemas]
2.1.2.44 Conventions for specifying distribution
information
A consistent approach for
specifying the onlineResource for GTS datasets is encouraged.
Recommendation 44:
for GTS products intended for global exchange, the onlineResource attribute
of the MD_Distributor object should conform to the following
syntax:
· http://«hostname»/«path»/«MD_Metadata/fileIdentifier»
where:
·
«hostname»/«path»/ refer to the location of the web-service
that serves the GTS product on behalf of the data-owner. This will normally be
the NC or DCPC who is responsible for publishing the product, but may be a GISC node who has agreed to
serve the ‘source’ data-files on their behalf.
· «MD_Metadata/fileIdentifier» is the globally unique identifier of the
metadata record that describes the product being served.
Example implementation of such
web service is available at
http://www.gisc.kishou.go.jp/cgi-bin/gisccache;
in this case
http://www.gisc.kishou.go.jp/cgi-bin/gisccache/urn:x-wmo:md:int.wmo.wis::SMJP02RJTD
should be onlineResource for SMJP02 RJTD.
GISCs will be able to identify
GTS products (for global exchange) using the citation authority in the
mandatory «MD_Metadata/fileIdentifier», being "int.wmo.wis", irrespective of the approach used
to specify the online resource. Once identified as GTS products, the GISCs will
amend the metadata served in response to a query to offer access to the local
GISC cache in addition to the original source.
Recommendation 45: when serving querying responses from the GISC search portal, GISCs will amend the information served to the user by inserting an additional MD_Distributor object that describes their local GISC-cache. This gives the recipient a choice of destinations: the original source or the local cache. Such amended metadata must not be re-distributed for other GISCs]. There is no restriction on the format or structure of onlineResource attributes describing the local GISC-cache. Also note that there is no restriction on the format or structure of onlineResource attributes describing products that are not globally exchanged: i.e. those served only from an NC or DCPC and do not form part of the GISC cache.
This recommendation
should ensure compliance with INSPIRE which mandates a gmd:transferOptions element for every
"URL available to obtain more information on the resources and / or access
related services". Each additional MD_Distributor object will contain an
additional transferOptions element.
An 'empty' gmd:distributionInfo object is included by way
of example:
<gmd:distributionInfo>
<gmd:MD_Distribution>
<gmd:distributor>
<gmd:MD_Distributor>
<gmd:distributorContact>
...
</gmd:distributorContact>
<gmd:distributorTransferOptions>
<gmd:MD_DigitalTransferOptions>
<gmd:onLine>
<gmd:CI_OnlineResource>
<gmd:linkage>
<gmd:URL>XXX</gmd:URL>
</gmd:linkage>
<gmd:protocol>
<gco:CharacterString>WWW:LINK-1.0-http--link</gco:CharacterString>
</gmd:protocol>
<gmd:name>
<gco:CharacterString>XXX</gco:CharacterString>
</gmd:name>
<gmd:description>
<gco:CharacterString>XXX</gco:CharacterString>
</gmd:description>
</gmd:CI_OnlineResource>
</gmd:onLine>
</gmd:MD_DigitalTransferOptions>
</gmd:transferOptions>
</gmd:distributorTransferOptions>
</gmd:MD_Distributor>
</gmd:distributor>
</gmd:MD_Distribution>
</gmd:distributionInfo>
The following schematics
provide more information:
Example:
·
Original onlineResource citation:
<gmd:URL>
http://gisc.dwd.de/GISC_DWD/Level/2/urn:x-wmo:md:int.wmo.wis::SMAA01EDZW
</gmd:URL>
·
Additional onlineResource citation
for DWD GISC-node:
<gmd:URL>
http://gisc.dwd.de/GISC_DWD/retrieve.do?pidpat=urn:x-wmo:md:int.wmo.wis::SMAA01EDZW&TOPLEVEL=False
</gmd:URL>
Readers should note that the «hostname» & path «path» are defined by the data-provider to
suit their local policies, or those of their delegated agents where a GISC
serves the source data-files on their behalf.
2.1.2.45 Metadata ownership & publication
Recommendation 46:
Continuing current GTS practices and procedure, metadata ownership resides with
the data-provider organization. Only the data-provided organization has the
authority to create or update metadata for their products they provide.
2.1.2.46 Each data-provider is responsible for the
accuracy of their metadata. Note that data that does not have a corresponding
metadata record will not be visible in the catalogue: the implication is that
it will not be discoverable!
Recommendation 47:
the maintenance schedule for metadata will be identical to those in the Manual
on GTS for maintaining Vol. C1
2.1.2.47 Each NC or DCPC will be affiliated with a
specific GISC. NC or DCPCs must agree a mechanism to publish (& delete)
metadata records with their affiliated GISC.
Recommendation 48:
bi-lateral agreement between NC / DCPC and their affiliated GISC must include
information on metadata exchange and deletion mechanisms.
2.1.2.48 GISCs do not create any original metadata –
they only publish content from NCs and DCPCs. However, it is the GISC’s
responsibility to ensure that their affiliated NCs or DCPCs are complying with
the metadata management policies. The WMO Secretariat currently maintains a
list of additional data separately from Volume C1 on the basis on the
information provided by the Permanent Representatives.
2.1.2.49 As noted in the previous discussion on
dataset hierarchies, some elements of metadata records can be normalized into
static metadata components and referenced via xlink
from within the metadata records. Use of this mechanism is considered to
simplify metadata management as all metadata records who reference a given
component will automatically be updated if the source metadata is updated.
Depending on consumer-preference, these xlink
references may be resolved or not: retaining the xlink
reduces the metadata record size, resolving the xlink
(i.e. inserting the content from the metadata component) simplifies parsing.
2.1.2.50 Creation of initial 'baseline' metadata
records from WMO No. 9
Météo-France had developed a
software package for the conversion of WMO No. 9 Volume C1 into ISO 19115
compliant metadata records. The procedure creates a DAR metadata record
compliant with version 1.1 of the WMO Core Profile for every bulletin found in
Volume C1. Information is extracted from the bulletin definition and enriched
with additional sources of information, including WMO documents and references
– WMO No. 9 Volume A, WMO No. 306 Manual on Codes, WMO No. 386 Manual on the
GTS -.Rules are created to interpret and mine information from Volume C1 free-format
fields. They reflect recurring syntaxes found in Volume C1. These rules are
provided in annex 1 to IPET-MDI-I/Doc. 2.1.2(3). The meeting stressed the
need for Members to follow these rules to ensure the best metadata records are
created. The recommendations of the IPET-MDI-I as regards the implementation of
the WMO core profile will be introduced by Météo-France in a new version of the
software package provided they do not necessitate long developments.
2.1.2.51 Procedure for generation and validation of
baseline metadata records
Météo-France proposed the
following procedure for the generation and validation of the catalogue of
metadata records for the bulletins of Volume C1:
·
With the assistance of the Secretariat, Météo-France will
implement the pre-validation procedure defined in paragraph 4 of
IPET-MDI-I/Doc. 2.1.2(3);
·
Météo-France will generate the metadata records for every
WMO Member, and make them available to Members. The WMO Secretariat will inform Members of the availability of
GTS metadata records and validation procedure;
·
Members will review the records and edit all necessary
changes. If necessary, Météo-France will possibly provide guidance during this
process,
·
Once editing is complete, Members will provide their final
set of GTS metadata records to Météo-France, for insertion in the reference
set,
· Météo-France will provide
the complete final set of GTS metadata to WMO.
2.1.2.52 Support for non-expert metadata authors / validators
The meeting stressed the need for a sophisticated stylesheet that provides
guidance & in-line editing capabilities to support validation of baseline
metadata developed by Meteo France (see above
paragraph 2.1.2.28).
The maintenance of the DAR catalogues will require that the WMO Members provide
the information on additional data in the DAR catalogue and this will duplicate
the information provided to the Secretariat, with possible differences in the
information. Therefore, the creation of a DAR metadata catalogue
including information on additional data would lead to the parallel maintenance
of the two lists, each with the potential to appear as redundant and sources of
confusion.
Recommendation 49:
Arrangements between GISCs, MTN centres and the Secretariat, including a time
schedule for action, should be developed:
(a) To implement the pre-validation procedure
proposed by Météo-France and leading to a complete final set of GTS metadata:
(b) To ensure that the
updates to Volume C1 issued after the production of the complete final
catalogue of GTS metadata records by Météo-France be included in the catalogue
of metadata records, until Volume C1 be replaced by the DAR catalogue.
The meeting
recommended that procedures for maintaining Volume C1 the declaration of
additional data be reconsidered and agreed to submit this issue to the next
ICT-ISS. ET-OI should be involved in the development of these arrangements.
2.1.2.53 Marking metadata as draft
To support the initial implementation of WIS, Metéo France will create a complete set of metadata records
for the GTS products intended for global exchange. These metadata records will
form a baseline for the DAR catalogue until the data-owners (i.e. WMO
member-states & organizations) are ready to begin maintenance of their
metadata records. As these records are created by Metéo
France rather than the official data-owner, these records will be marked as
draft.
Once the metadata has been validated by the
appropriate member organization, ownership will be transferred and the 'DRAFT'
status will be removed. In order to ensure that DRAFT status is amended during
validation, the team recommend a scheme whereby the member organization will
need to overwrite an element with their own information.
The following schemes were reviewed but discarded:
·
MD_Metadata/metadataMaintenance/MD_MaintenanceInformation/maintenanceNote = “DRAFT”
· MD_Metadata/metadataConstraints/MD_Constraints/useLimitation = “DRAFT”
Recommendation 50:
Météo France ‘baseline’ metadata will be marked as DRAFT using the following
scheme:
· gmd:MD_Metadata/gmd:metadataMaintenance/gmd:MD_MaintenanceInformation/gmd:contact/gmd:CI_ResponsibleParty/gmd:organisationName = "Meteo France (on behalf of «NC or DCPC» by interim agreement with ICG-WIS)"
· gmd:MD_Metadata/gmd:metadataMaintenance/gmd:MD_MaintenanceInformation/gmd:contact/gmd:CI_ResponsibleParty/gmd:contactInfo/gmd:CI_Contact/gmd:address/gmd:CI_Address/gmd:electronicMailAddress = "quelqu-un@meteo.fr"
2.1.2.54 Multi-language metadata
Recommendation 51:
the following policies will apply to multi-language metadata records:
-
At a
minimum, metadata will be published in English
-
An abstract
must primarily be in English; alternative language versions may be provided
-
GISC
systems will always operate on the primary English metadata
- Where a 3rd party wishes add translation to a
metadata record, they must propose changes to the metadata custodian (data-owner)
for the record. Only the metadata custodian (or their delegated agent) has the
authority to update the metadata. Updates will be propagated via the WIS via
the normal mechanism.
The default language and character set of the
metadata record is explicited in the MD_Metadata/language and MD_Metadata/characterSet elements:
<gmd:language>
<gmd:LanguageCode
codeList="http://wis.wmo.int/2006/catalogues/gmxCodelists.xml#LanguageCode"
codeListValue="eng"/>
</gmd:language>
<gmd:characterSet>
<gmd:MD_CharacterSetCode
codeList="http://wis.wmo.int/2006/catalogues/gmxCodelists.xml#MD_CharacterSetCode"
codeListValue="utf8"/>
</gmd:characterSet>
Each alternate language for the metadata is defined
via a MD_Metadata/locale element:
<gmd:locale>
<gmd:PT_Locale id="locale-fr">
<gmd:languageCode>
<gmd:LanguageCode
codeList="http://wis.wmo.int/2006/catalogues/gmxCodelists.xml#LanguageCode"
codeListValue="fra"/>
</gmd:languageCode>
<gmd:characterEncoding>
<gmd:MD_CharacterSetCode
codeList="http://wis.wmo.int/2006/catalogues/gmxCodelists.xml#MD_CharacterSetCode"
codeListValue="utf8"/>
</gmd:characterEncoding>
</gmd:PT_Locale>
</gmd:locale>
Each
metadata element with a CharacterString type and free
text domain can be instantiated with a gmd:PT_FreeText_PropertyType type:
<gmd:abstract xsi:type="gmd:PT_FreeText_PropertyType">
<gco:CharacterString>Abstract in english</gco:CharacterString>
<gmd:PT_FreeText>
<gmd:textGroup>
<gmd:LocalisedCharacterString locale="#locale-fr">Résumé en français</gmd:LocalisedCharacterString>
</gmd:textGroup>
<gmd:textGroup>
<gmd:LocalisedCharacterString
locale="#locale-sp">Resumen en espanol</gmd:LocalisedCharacterString>
</gmd:textGroup>
</gmd:PT_FreeText>
</gmd:abstract>
In the example above, two
alternate languages are assumed to be defined. The abstract element is provided
in the default language with a common gco:CharacterString element. An additional gmd:PT_FreeText element is present,
containing possibly a gmd:textGroup element for every
alternate translation.
Translations may be defined in translation files instead of being embedded in
the metadata record.
In this case, it is simpler to
group in a single file the definition of one alternate language and the
associated translations, each translated string identified by a unique id
attribute. Here is an example translation file:
<gmd:PT_LocaleContainer
xmlns:gco="http://www.isotc211.org/2005/gco"
xmlns:gmd="http://www.isotc211.org/2005/gmd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.isotc211.org/2005/gmd
http://www.isotc211.org/2005/gmd/gmd.xsd">
<!-- gmd:description element not shown -->
<gmd:locale>
<gmd:PT_Locale id="locale-fr">
<gmd:languageCode>
<gmd:LanguageCode
codeList="http://wis.wmo.int/2006/catalogues/gmxCodelists.xml#LanguageCode"
codeListValue="fra"/>
</gmd:languageCode>
<gmd:characterEncoding>
<gmd:MD_CharacterSetCode
codeList="http://wis.wmo.int/2006/catalogues/gmxCodelists.xml#MD_CharacterSetCode"
codeListValue="utf8"/>
</gmd:characterEncoding>
</gmd:PT_Locale>
</gmd:locale>
<!-- gmd:date element not shown -->
<!-- gmd:responsibleParty element not shown -->
<gmd:localisedString>
<gmd:LocalisedCharacterString
locale="#locale-fr" id="abstractfr">Résumé en français</gmd:LocalisedCharacterString>
</gmd:localisedString>
<!-- other gmd:localisedString elements not shown
-->
</gmd:PT_LocaleContainer>
The translated values of textual metadata elements are
then referenced in the multi-lingual metadata as in:
<gmd:abstract xsi:type="gmd:PT_FreeText_PropertyType">
<gco:CharacterString>Abstract in english</gco:CharacterString>
<gmd:PT_FreeText>
<gmd:textGroup
xlink:href="fr-fr.xml#abstractfr"/>
</gmd:PT_FreeText>
</gmd:abstract>
Note: the object type MemberName
is used within software systems like a foreign key. As such it is never
translated in multi-lingual metadata.
2.1.2.55 Metadata deletion
Recommendation 52:
Only the data-owner has the authority to delete metadata records. The
circumstances allowing deletion of metadata records include:
- When incorrect metadata is mistakenly or
maliciously published
- When product or information is no longer
available the metadata record must be removed from the DAR catalogue
Recommendation 53:
When GISC is requested to delete a metadata record it must remove the record
from the DAR catalogue (so that it can no longer be discovered), but stores the
record temporarily for a period of time prior to purging. Recommended ‘grace
period’ is 7-days.
2.1.2.56 An NC or DCPC may choose to maintain a
historical archive of metadata records, even if the dataset is no longer
available. OAI-PMH is the mandatory mechanism for GISC-to-GISC synchronization
of DAR catalogues OAI-PMH can (optionally) support propagation of deletion.
Recommendation 54:
the OAI-PMH protocol will be used to achieve GISC-to-GISC synchronization of
deleted records.
2.1.2.57 Notifying an affiliated GISC regarding the
deletion of metadata records is a subject to local agreement.
Recommendation 55:
bi-lateral agreement between NC / DCPC and their affiliated GISC must include
information on metadata exchange and deletion mechanisms.
Potential mechanisms may
include:
·
If OAI-PMH harvesting used to publish metadata to the GISC,
use the OAI-PMH protocol; or
·
Publication of a service message (format to be agreed
bi-laterally) to GISC requesting deletion of record (using MD_Metadata/fileIdentifier as primary key); or
· GISCs may provide
metadata editor to allow data originator to delete the record themselves.
2.1.2.58 Implementation note from DWD:
jOAI
monitors each directory of files that is configured in the system and automatically
adds, updates or deletes items from the OAI repository as files are added,
updated or deleted from the directories. After the initial configuration, the
synchronization between the files and the OAI repository occurs automatically
every 8 hours or may be synchronized manually at any time.
2.1.2.59 Publication of Metadata of ISO copyright
material
Agreement between WMO & ISO
TC/211 secretariats allows the use of final draft docs for development of WMO
Core Profile. Publications from WMO must include note referencing copyright
remains with ISO. WMO are requested to re-publish only content that is deemed
of interest for our community. The implication is that IPET-MDI can publish a
document (or documentation package) that includes all necessary ISO copyright
material thus removing the need for WMO documentation to refer to external ISO
standards documents.
It should be noted that the agreement between WMO and ISO does not extend to
IOC, thus the inclusion of JCOMM is to be confirmed.
2.1.2.60 Guidance notes for metadata authors
Ted Habermann
presented the guidance material developed for NOAA. This included:
Hyper-linked documentation
·
‘Rubric’ / training aids – stylesheets
that provide metadata quality indexes & guidance on how to fix issues. A
number of different rubrics were displayed, each responding to a specific
training requirement.
·
FAQ stylesheets
· Stylesheets that provide editing
interfaces for metadata with built-in guidance.
More information can be found here: https://www.nosc.noaa.gov/dmc/swg/wiki/index.php?title=Creating_Good_Documentation
Recommendation 56:
IPET-MDI will adopt a similar package of guidance material as NOAA.
2.1.2.61 Versions and future update cycles
As one of the recommendations
made by IPET-MDI is the use of MI_Metadata as the recommended root
element. This implies inclusion of ISO19115-2:2009.
Recommendation 57:
The next release of WMO Core Profile metadata standard will by 1.2
Recommendation 58:
Subsequent releases of the WMO Core Profile metadata standard will employ
tertiary / minor updates; 1.2.1, 1.2.2, 1.2.3 etc.
2.1.2.62 During the time until Congress 2011, the WMO
Core Profile metadata standard is expected to have a number of updates. A
release process for this period is defined below. After Congress 2011 a formal
process similar to that used for the Manual on Codes may be defined using an
annual update and approval cycle.Milestone
dates are:
·
v1.2: 4th June 2010 – publication of v1.2
including recommendations from IPET-MDI-1 & support of WMO ET-GDDP
assessment phase
·
v1.2.1: 27st August
2010 – start of preparations for CBS demo
·
v1.2.2: 1st October 2010 – CBS demo
· v1.2.3: 11th
April 2011 – next ICG-WIS meeting & preparations for Congress demo in
mid-May
2.1.2.63 v2.0 is expected to incorporate a move to
ISO19115:2012 and harmonization with JCOMM & Hydrology metadata profiles.
The timescales for ISO19115 revision are:
·
Committee Draft (Nov 2010),
·
Draft International Standard [DIS] (2011),
· Final publication
ISO19115:2012
Revision timelines for ISO19115
will have significant impact on the timescales for moving WMO Core Profile
metadata standard to v2.0.
2.1.2.64 Candidate release process (until congress
2011):
·
OPAG-ISS / WISPO will establish a set of agreed release milestones
for metadata guidelines. These will be organized to support the WIS project
plan; e.g. guidelines released with sufficient lead-time ahead of major
deliverables. The release schedule is critically important to maintain as this
is the 'tempo' of change; implementers can plan to adapt at known dates and be
assured that there will be no change until the next release milestone. Each
release milestone must clearly define the reasons why it exists - what future
project deliverable / outcome does it support?
·
JIRA release management software [web-based service,
provided by NCAR (Don Middleton)] used to capture issues.
·
IPET-MDI chair will distribute 'problem tickets' to the
team, whereupon they will be assessed each in turn against the growing
historical knowledge base and 'inside' knowledge.
·
Where IPET-MDI deem it necessary to propose new metadata
usage guidelines to clarify or resolve issues, such problem tickets will be
allocated to the AGREED release milestones in consultation with ET-WISC.
·
Where metadata usage guidelines are considered to impact the
GISC implementation community, then a future release milestone will be
identified where the guideline becomes BINDING. Until that time, the guideline
is not enforceable but will be marked as DEPRECATED in the automated
validation. Any instances of deprecated practices will identify when they are
due to become binding.
·
IPET-MDI will develop & publish the guidelines and
associated collateral material (including updates to the automated validation
scripts) in time to meet the release milestone.
·
Release package ‘manifest’ – host @ wis.wmo.int/2010/...
o
Schema(s) iso19139
o
Schematron rules
o
Controlled vocabularies, code-list extensions (&
gazetteers)
o
Guidance notes – wiki (& later PDF document compiled by
WISPO-contractor)
o
Sample metadata
o
Static metadata components & component management tools
o
Conformance tests
o
Stylesheets + ‘rubric tests’
[prioritize ‘minimum metadata’ requirements]
o
Metadata editor stylesheets;
template metadata
o
UML
Recommendation 59:
the candidate release process was approved.
Recommendation 60:
all material pertaining to a release of the WMO Core Profile standard will be
published to:
- http://wis.wmo.int/«YYYY»
Note that GISCs are likely to
keep a local copy of these entities in order to speed validation etc.
The WMO Secretariat will support
the release process.
The IPET-MDI team will work
closely with the WISPO and their nominated expert contractor to further develop
the metadata guidelines into the Manual on WIS.
2.1.2.65 ISO19115:2012 candidate revisions
Outputs from ISO19115 revision
team that are being considered:
·
Newconcept: deprecation ... things
in 19115 will be deprecated to ensure backward compatibility whilst allowing
strong guidance on preferred methods ... as much as one would want to make the
new stuff mandatory, you cannot without impacting backward compatibility!
·
MD_MetadataHierarchyLevel
·
hierarchyLevel
·
hierarchyLevelName
·
... to ensure that name & level are connected somehow
·
MD_Reference
·
identifier
·
onlineResource
·
... characterstring vs identifier [MD_Identifier] ...
people are including the namespace in the identifier which is really a
citation to the authority ... MD_Identifier includes
a unique identifier (i.e. 32-byte UUID) + citation authority (namespace: uk.gov.metoffice)
·
... onlineResource allows explicit
reference to the URL where the object can be found
· ... *may* be replaced
with just a Citation object – which would force the addition of title and date
3. AWARENESS
OF THE DEVELOPMENT OF A WMO CORE PROFILE OF THE ISO 19100 SERIES OF STANDARDS
FOR DATA AND METADATA
WITHIN THE WMO COMMUNITY
3.1 There is a special relationship
between WIGOS (WMO Integrated Observing System http://www.wmo.int/pages/prog/www/wigos/index_en.html)
& WIS (WMO Information System http://www.wmo.int/pages/prog/www/WIS/). It should be noted
that WIGOS depends on the successful implementation of WIS but not vice-versa.
Fundamental to the success of WIGOS will be the ability of the WIS
infrastructure to cope with the diverse information requirements from the
integrated sensor networks. This will require further evolution of the metadata
and data standards managed by IPET-MDI.
3.2 The
meeting noted the information on the development of standards for WMO data and
associated metadata relevant to WIGOS given in the document “WIGOS
standardization framework for data and associated metadata” (see
IPET-MDI-I/Doc. 4.2(1). It invited the Secretariat to continue updating the
document “WIGOS standardization framework for data and associated metadata”
with a view to fostering the awareness of the development of the standards for
data and metadata for the development of the WIGOS.
4.1 Actions
arising from this meeting
The meeting agreed on the
action sheet included in Annex to this paragraph. The meeting noted that the
chair of the IPET-MDI will submit the recommendations of the IPET-MDI to the
meeting of the OPAG-ISS Implementation Coordination Team on ISS (ICT-ISS)
scheduled in Geneva from 27 to 30 September 2010. The outcomes of the meeting
of the ICT-ISS will be submitted to the Extra-ordinary session of CBS
(Windhoek, Namibia, 17-24 November 2010).
4.2 Tooling
to support collaborative development of WMO Core Profile standard
4.2.1 The WIKI requirements for online tools
are:
-
Hyper-text documentation
-
Version control updates
-
The ability to rapidly ‘dump’ content for group assessment
or ad-hoc discussion
- The ability to organize
content for improved clarity
Recommendation 61: IPET-MDI adopt the WIS-WIKI [http://www.wmo.int/pages/prog/www/WIS/wiswiki/tiki-index.php]
Recommendation 62:
use of IPET-MDI Huddle site will discontinued
4.2.2
Working
practices on WIS WIKI
- Do not delete content
from wiki-pages; strikethrough text then add your
name and editorial comment. The ‘document owner’ will resolve the amendments
- There is no ability to
check out attached documents for update. Please be aware of other users and
avoid over-writing their changes. It is your responsibility to merge content
from updated source & your amendments.
4.2.3 The use of Tiki-wiki
software to underpin the WIS WIKI caused concern amongst the team. Recommended
alternatives included Confluence
[http://www.atlassian.com/software/confluence/] and MediaWiki
[http://www.mediawiki.org/wiki/MediaWiki]. Both of these tools have the capacity
to publish PDF document output from WIKI-pages (e.g.
http://www.mediawiki.org/wiki/Extension:EPubExport).
[Action
MDI-1-xxvi: Ted, Dave & Timo - discuss choice of wiki software
for future robustness & capability]
4.2.4 The version control capabilities of the wiki may be sufficient for our needs. Alternatively, we may
use subversion [svn - http://subversion.tigris.org/]
[Action
MDI-1-xxvii: Michael - assess whether NCAR could host a WIS subversion repository]
4.2.5 The OCG MetOcean
Domain Working Group wiki is the location where
details of the conceptual modelling activity are posted:
http://external.opengeospatial.org/twiki_public/bin/view/MetOceanDWG/WebHome
4.2.6 JIRA is being used, courtesy of NCAR, to
manage problem tickets and releases for WIS. The JIRA online tool can be
found here:
All IPET-MDI members have been
added to this JIRA WIS user list. Members are directed to use IPET-MDI
component of the WIS project to filter for IPET-MDI issues.
The meeting was closed on 29
April 2010 at 18:20 p.m.
Annex to paragraph 1.1.1
List of
participants
CHAIRPERSON:
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Met Office
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Meteorological Agency (JMA)
1-3-4
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80 51806841
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TECHNICAL COMMISSIONS
REPRESENTATIVES:
JCOMM
Mr G. Reed Australian
Ocean Data Centre Joint Facility
Fleet
Headquarters
Wylde Street
Potts
Point NSW 2011
AUSTRALIA
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2 9359 3141
Fax: +61
2 9359 3120
E-mail: greg@metoc.gov.au
WMO SECRETARIAT:
C/DRMM Mr
Pierre KERHERVÉ
WIS/PM Mr
David THOMAS
SO/DRMM Mr
Atsushi SHIMAZAKI