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Clemens Portele – interactive instruments GmbH

Report on using Geographic Information standards (ISO 19100, OGC) in the planning of the WIS with a focus on metadata. Clemens Portele – interactive instruments GmbH. Overview. This presentation addresses four topics:

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Clemens Portele – interactive instruments GmbH

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  1. Report on using Geographic Information standards (ISO 19100, OGC) in the planning of the WIS with a focus on metadata Clemens Portele – interactive instruments GmbH GI standards and the WIS - Clemens Portele - 11.09.2005

  2. Overview This presentation addresses four topics: • Topic A: Assessment of the ISO 19100 series and OGC specifications; identification of standards that have the highest priority in order to deliver a workable metadata system in the WIS plus such that are relevant for supporting the work of the data provision centres • Topic B: WMO Core Profile of the ISO 19115 metadata standard; identification of issues and recommendations; coverages vs features • Topic C: Metadata tools • Topic D: High level “road map” GI standards and the WIS - Clemens Portele - 11.09.2005 2

  3. WMO Information System (WIS) • In 2003 WMO approved the concept of a WIS. The WIS will provide a single coordinated global infrastructure for the collection and sharing of information in support of all WMO and related international programmes. GI standards and the WIS - Clemens Portele - 11.09.2005 3

  4. Topic A: Assessment of ISO 19100 series plus OGC specifications • Identify a subset of the standards that have the highest priority in order to deliver a workable metadata system in the WIS • Identify a further subset of standards that is required to support the work of the data provision centres being designed by the WIS team • Note: The following assessment was done after a brief analysis and discussion of the WIS (metadata) requirements with WMO experts and is intended as a starting point for the future work within WMO GI standards and the WIS - Clemens Portele - 11.09.2005 4

  5. WIS tasks (simplified) Consumer (Client) Node Retrieve data Subscribe to data Discover data (retrieve metadata) Abstracted from the requirements, scenarios, use cases as described in [SIMDAT] Node = GISC, NC, DCPC GI standards and the WIS - Clemens Portele - 11.09.2005 5

  6. WIS tasks (simplified) Provider (Client) Node Send data Send metadata Abstracted from the requirements, scenarios, use cases as described in [SIMDAT] Node = GISC, NC, DCPC GI standards and the WIS - Clemens Portele - 11.09.2005 6

  7. WIS tasks (simplified) Admin (Client) Node Manage node Monitor and control node Manage users, data policy and billing Abstracted from the requirements, scenarios, use cases as described in [SIMDAT] Node = GISC, NC, DCPC GI standards and the WIS - Clemens Portele - 11.09.2005 7

  8. WIS tasks (simplified) Node Node Send data Send metadata Request data (returns data) Request data (returns reference + maybe credentials) Abstracted from the requirements, scenarios, use cases as described in [SIMDAT] Node = GISC, NC, DCPC GI standards and the WIS - Clemens Portele - 11.09.2005 8

  9. WIS tasks (simplified) Node Authenticate user Authorize user Log actions Manage real-time data Watch subscriptons Abstracted from the requirements, scenarios, use cases as described in [SIMDAT] Node = GISC, NC, DCPC GI standards and the WIS - Clemens Portele - 11.09.2005 9

  10. Relevant standards for WMO (WIS, metadata) Metadata standards (including drafts): • ISO/TC 211 • ISO 19115 - Metadata • ISO 19115-2 - Metadata extension for imagery and gridded data • ISO 19119 - Services • ISO/TS 19139 – XML Schema implementation of ISO 19115 • OGC • OGC Catalog Service • ebRIM Application Profile of the OGC Catalog Service (Web Registry Service) • ISO 19115/19119 Application Profile of the OGC Catalog Service  See Topic B for details Adopted/Published document Draft document documents with high relevance (underlined) GI standards and the WIS - Clemens Portele - 11.09.2005 10

  11. Relevant standards for WMO (WIS, metadata) Data quality standards ISO 19113 - Quality principlesISO 19114 - Quality evaluation proceduresISO 19138 – Data quality measures Reference Model ISO 19101 – Reference modelISO 19101-2 – Reference model (Imagery) GI standards and the WIS - Clemens Portele - 11.09.2005 11

  12. Relevant standards for WMO (WIS, metadata) Application schemas, feature catalogues, data product specifications ISO 19109 - Rules for application schemaISO 19110 - Feature cataloguing methodologyISO 19131 - Data product specification Coverages / Imagery and gridded data ISO 19123 - Schema for coverage geometry and functionsISO 19129 - Imagery, gridded and coverage data frameworkISO 19130 - Sensor and data model for imagery and gridded data GI standards and the WIS - Clemens Portele - 11.09.2005 12

  13. Relevant standards for WMO (WIS, metadata) Spatial information ISO 19107 - Spatial schema ISO 19111 - Spatial referencing by coordinatesISO 19112 - Spatial referencing by geographic identifiers Temporal information ISO 19108 - Temporal schema ISO 19141 – Schema for moving features GI standards and the WIS - Clemens Portele - 11.09.2005 13

  14. Relevant standards for WMO (WIS, metadata) Registers and registries ISO 19135 – Procedures for registration of geographic information items OGC Catalog Service ebRIM Application Profile of the OGC Catalog Service (Web Registry Service) Encoding OGC Geography Markup Language (GML) / ISO 19136 ISO/TS 19139 – XML Schema implementation of ISO 19115 OGC GML in JPEG 2000 for Geographic Imagery (GMLJP2) GI standards and the WIS - Clemens Portele - 11.09.2005 14

  15. Relevant standards for WMO (WIS, metadata) Data Access Web Services OGC Web Map Server Interface (WMS) / ISO 19128 OGC Web Feature Service (WFS) / ISO 19142 OGC Filter Encoding / ISO 19143 OGC Web Coverage Service (WCS) Portrayal ISO 19117 – PortrayalOGC Styled-Layer Descriptor GI standards and the WIS - Clemens Portele - 11.09.2005 15

  16. Relevant standards for WMO (WIS, metadata) Sensors and Sensor Web Enablement OGC Sensor Observation Service OGC Sensor Planning Service OGC Sensor Alert Service ISO 19130 - Sensor and data model for imagery and gridded data Geographic Digital Rights Management (GeoDRM) OGC GeoDRM Reference Model GI standards and the WIS - Clemens Portele - 11.09.2005 16

  17. Topic B: WMO Core Profile of the ISO 19115 metadata standard • Consistency of the WMO Core Profile of the ISO 19115 metadata standard with future evolution of the ISO 19100 family of standards • Key omissions that would prevent widespread uptake of data described using the WMO Core Profile among other communities • Use of Coverages vs Features a combination of both to describe data of interest to WMO GI standards and the WIS - Clemens Portele - 11.09.2005 17

  18. Metadata standards overview (including drafts) • ISO 19115 - Metadata • ISO 19115-2 - Metadata extension for imagery and gridded data • ISO 19119 - Services • ISO/TS 19139 – XML Schema implementation of ISO 19115 • OGC Catalog Service • ebRIM Application Profile of the OGC Catalog Service (Web Registry Service) • ISO 19115/19119 Application Profile of the OGC Catalog Service GI standards and the WIS - Clemens Portele - 11.09.2005 18

  19. ISO 19115:2003 - Metadata • Identifies the metadata required to describe digital geographic data. Metadata is applicable to independent datasets, aggregations of datasets, individual geographic features, and the various classes of objects that compose a feature. Metadata shall be provided for geographic datasets and may, optionally, be provided for aggregations of datasets, features, and attributes of features. • International Standard • Used as basis for WMO Core Metadata Profile GI standards and the WIS - Clemens Portele - 11.09.2005 19

  20. ISO 19115:2003 Packages Constraint Content Citation and responsible party Portrayal catalogue Distribution Maintenance Metadata entity set Metadata extension Application schema Identification Data quality Reference system Extent Units of Measure Spatial representation GI standards and the WIS - Clemens Portele - 11.09.2005 20

  21. ISO 19115 Part 2:Extensions for imagery and gridded data • Extends ISO 19115:2003 Geographic Information – Metadata by defining the schema and additional metadata required for imagery and gridded data • Still a Working Draft ! • Not stable • Recommendation: • Monitor development • Evaluate drafts • Provide comments GI standards and the WIS - Clemens Portele - 11.09.2005 21

  22. ISO WD 19115 Part 2 Packages <<Leaf>> <<Leaf>> Content information - Constraint information Imagery <<Leaf>> <<Leaf>> Content information Citation and responsible party information <<Leaf>> Portrayal catalogue information <<Leaf>> Distribution information <<Leaf>> Citation and responsible party information - Imagery <<Leaf>> Maintenance information <<Leaf>> Metadata extension information <<Leaf>> Metadata entity set information <<Leaf>> Application schema information <<Leaf>> Reference system information <<Leaf>> (from ISO 19115 Metadata) Identification information <<Leaf>> <<Leaf>> Spatial representation Units of Measure information <<Leaf>> Identification information - Imagery <<Leaf>> Spatial representation information - Imagery <<Leaf>> Requirements information - Imagery <<Leaf>> <<Leaf>> Data quality information Acquisition information - Imagery <<Leaf>> Extent information (from ISO 19115 Metadata) <<Leaf>> <<Leaf>> Data quality Extent information - information - Imagery Imagery GI standards and the WIS - Clemens Portele - 11.09.2005 22

  23. ISO/DTS 19139 – XML Schema implementation • „Given the abstract nature of the ISO 19115 specification, the actual execution of geographic information metadata could vary based on the interpretation of the metadata producers *). In an attempt to facilitate the standardization of implementations, this comprehensive dataset metadata implementation specification provides single UML interpretation and XML schema for carrying out the ISO 19115 metadata standard. This specification is meant to enhance interoperability by providing a common specification for describing, validating and exchanging metadata about geographic datasets, dataset series, individual geographic features, feature attributes, feature types, feature properties, etc.“ *) and it does, see WMO Core Metadata Profile XML vs other XML encodings of ISO 19115 GI standards and the WIS - Clemens Portele - 11.09.2005 23

  24. Approach of ISO/DTS 19139 UML 19115 ISO Abstract Adaptation Specification ISO Implementation Specification UML 19139 XML Schema 19139 scripts ISO Implementation Specification Community Profile scripts XML Schema 19139 ext. UML 19139 ext • Composed of three essential parts in the Requirements Clause: • ISO 19139 expands Annex E of ISO 19115 to show all the metadata elements (Not XML Specific) • ISO 19139 also defines new constraint types to further refine the metadata elements for implementation (Not XML Specific) • ISO 19139 defines XML Schema for geographic information dataset metadata (XML Specific) • Community profiles may extend schema of ISO 19139 Status: Submitted to ISO as DTS (Draft Technical Specification), but not yet published  expected to be stable, but changes may still occur GI standards and the WIS - Clemens Portele - 11.09.2005 24

  25. ISO 19119:2005 – Services Scope: • Identifies and defines architecture patterns for service interfaces used for geographic information and definition of the relationships to the Open Systems Environment model • Presents a geographic services taxonomy and a list of example geographic services placed in the services taxonomy • Prescribes how to create a platform-neutral service specification, and how to derive platform-specific service specifications that are conformant with this • Provides guidelines for the selection and specification of geographic services from both platform-neutral and platform-specific perspectives. GI standards and the WIS - Clemens Portele - 11.09.2005 25

  26. ISO 19119:2005 Packages <<Leaf>> <<Leaf>> Service Service Model Metadata <<Leaf>> <<Leaf>> <<Leaf>> Records and Class Data quality information Identification information Metadata GI standards and the WIS - Clemens Portele - 11.09.2005 26

  27. ISO 19119:2005 - Geographic services taxonomy • Geographic human interaction services • Geographic model/information management services • Geographic workflow/task management services • Geographic processing services • Geographic processing services – spatial • Geographic processing services – thematic • Geographic processing services – temporal • Geographic processing services – metadata • Geographic communication services GI standards and the WIS - Clemens Portele - 11.09.2005 27

  28. Proposed amendment to ISO 19119:2005 • An amendment to Service Metadata defined in ISO 19119 has been proposed based on implementation experience and has been accepted by ISO/TC 211 as a new work item • Changes are proposed to the abstract schema, primarily concerning the relation between service metadata and dataset metadata. The extensions being proposed to ISO 19119 stem from requirements arising as a result of the practical experience being made with services in a Spatial Data Infrastructure in connection with and a nationwide catalogue service and the countries/states/regions bordering it. Hence the extensions are proposed from the background of usage within spatial data infrastructures, following the publish-find-bind principle. GI standards and the WIS - Clemens Portele - 11.09.2005 28

  29. OGC Web ServicesTypical pattern of usage Search Engine Find Publish Chain Bind Information Resources GI standards and the WIS - Clemens Portele - 11.09.2005 29

  30. OGC Catalog Service 2.0.0 and Profiles • The OGC Catalog Service provides the ability to search and retrieval of descriptive information (metadata) on an information resource (dataset, service, schema, etc.) using the same set of fields, the same operations and get similarly structured results from different servers • The OGC Catalog Service itself provides an abstract catalog access model and supports any metadata model with abstract query points • Requires core queryable and core returnable properties based on Dublin Core metadata elements • Three protocol bindings: CORBA, Z39.50/ISO 23950, and HTTP • Expects companion Application Profile document to complete implementation • Two Application Profiles available (next slides), both are OGC Recommendation Papers (i.e., not yet adopted specifications) • Adopted OGC Implementation Specification, scheduled to be submitted to ISO/TC 211 for standardization GI standards and the WIS - Clemens Portele - 11.09.2005 30

  31. OGC Catalog ServiceCore queryable properties • Enable simple cross-profile discovery, must be supported by all application profiles • Current list: • Subject • Title • Abstract • AnyText • Format • Identifier • Modified • Type • Envelope (lat-lon bounding box) • CRS (coordinate reference system) • Association (source and target resource plus relation name) GI standards and the WIS - Clemens Portele - 11.09.2005 31

  32. OGC Catalog ServiceCore returnable properties Permit the minimal implementation of a catalogue service independent of a companion application profile use of metadata returned from different systems and protocol bindings Expressed using the nomenclature and syntax of Dublin Core Metadata, ISO 15836 Current list: dc:title dc:creator dc:subject dct:abstract dc:publisher dc:contributor dc:date dc:type dc:format dc:identifier dc:source dc:language dc:relation dct:spatial dc:rights GI standards and the WIS - Clemens Portele - 11.09.2005 32

  33. ISO 19115/19119 Application Profile of the OGC Catalogue Service • Manages metadata resource types for data and service descriptions based on ISO 19115 and ISO 19119 (including the proposed amendment) • All characteristic metadata are searchable • Assertions can be traversed that effectively define data and service associations • Originated in SDIs in Germany and is in deployment in various parts of Europe • Uses ISO/PDTS 19139 for the XML encoding of ISO 19115 • OGC Recommendation Specification, expected to become an adopted specifciation GI standards and the WIS - Clemens Portele - 11.09.2005 33

  34. ebRIM Application Profile of the OGC Catalogue Service • ebRIM = ebXML Registry Information Model (developed by OASIS, http://www.oasis-open.org/) offers a method for defining and managing interoperable registries and repositories. • General purpose registry that can be applied to describe data, services, schemas, documents, dictionaries, symbol libraries, etc. • Adopts ebXML RIM metadata model for query on small set of common properties • Can be used to implement the ISO19115/19119 Application Profile • OGC Recommendation Specification, expected to become an adopted specifciation GI standards and the WIS - Clemens Portele - 11.09.2005 34

  35. Topic B.1: Consistency / potential issues of the WMO Core Profile • The core metadata elements of ISO 19115 are included in the profile  • XML encoding: It is expected that ISO/TS 19139 will become the de-facto standard for XML encoding of ISO 19115 data • Recommendations: • Use ISO/TS 19139 (not a WMO specific encoding) at least we communicating with external systems • If more economic, it may make sense to continue to use the current proprietary encoding internally in a system • Create a two-way mapping using XSLT between the two encodings to verify that a lossless mapping is possible GI standards and the WIS - Clemens Portele - 11.09.2005 35

  36. Topic B.1: Consistency / potential issues of the WMO Core Profile • Catalog Service support: • It is expected that Catalog Services will be a standard mechanism to access metadata • Recommendation: • Map WMO Core Profile information to the core properties of the Catalog Service • Test use of the Catalog Service with WMO Core Profile • Extensions to ISO 19115 do not follow the extension mechanism specified in ISO 19115 • Recommendation: Revise the WMS Core Profile to use the extension mechanism of ISO 19115 (and ISO/TS 19139 for XML Schema); see in particular Annex C of ISO 19115 GI standards and the WIS - Clemens Portele - 11.09.2005 36

  37. Topic B.1: Consistency / potential issues of the WMO Core Profile • (394) allows only a single date and not a period • Recommendation: Delete “or period” (as the dateTypes all reference an “instant”) or use the metadata extension mechanism • (143) must be a code list entry but the WMO description suggests that other data types may be used, too • Recommendation: Restrict to the use of the code list or use the metadata extension mechanism (n) row in the ISO 19115 data dictionary GI standards and the WIS - Clemens Portele - 11.09.2005 37

  38. Topic B.1: Consistency / potential issues of the WMO Core Profile • (39) is mandatory in the ISO 19115 Core metadata, but it is optional in he WMO Core Profile • Recommendation: Use a default value if data has no text in a language • (new) “irregularPointSet” is the domain of a multi point coverage for WMO internal use. For external use, the mandatory bounding box is used (currently codes are used to encode the irregular point sets). • Recommendation: Use the metadata extension mechanism GI standards and the WIS - Clemens Portele - 11.09.2005 38

  39. Topic B.1: Consistency / potential issues of the WMO Core Profile • (new) “keywordReferenceSource” is meant to extend the topic category enumeration which is too restricted to be useful for WMO; the element is intended to be a detailed reference to a hierarchical, multi-language dictionary • Recommendation: Create, Publish and maintain the dictionary in a registry; XML encodings can be based on GML = ISO 19136 gml:Dictionary (can be used to define hierarchical dictionaries) or ISO 19139 CT_Catalogue (supports dictionaries with multi-lingual entries) • Reference this dictionary through the thesaurusName citation GI standards and the WIS - Clemens Portele - 11.09.2005 39

  40. Topic B.1: Consistency / potential issues of the WMO Core Profile • (357) the axis orientation (signConvention) is part of the datum definition and not of the unit of measure information; however, this was considered important by WMO as it is a constant source of errors and ISO 19111 was considered insufficient • Recommendation: If the information shall be represented seperately, then an additional element should be defined using the extension mechanism to redundantly express this information – instead of encoding this in the unit information GI standards and the WIS - Clemens Portele - 11.09.2005 40

  41. Topic B.1: Consistency / potential issues of the WMO Core Profile • (new) HorizontalCoordinateType is redundant as the coordinate reference system of a geometry object is always provided as part of it • Recommendation: Delete this metadata element; if the intention is to provide information about the coordinate reference system of the data (rather than the extent information), then this should be provided via the “referenceSystemInfo” element • (341, 342) The definition of “polygon” is not consistent with ISO 19107 (which is used by ISO 19115); also, a polygon may contain holes • Recommendation: Reference the types specified in ISO 19107 Spatial Schema GI standards and the WIS - Clemens Portele - 11.09.2005 41

  42. Topic B.1: Consistency / potential issues of the WMO Core Profile • (351) If the temporal primitive is not used, this is not an instance of EX_TemporalExtent • Recommendation: Use the metadata extension mechanism to specify an extension of EX_TemporalExtent where “extent” is a TM_Period (“beginDateTime”,”endDateTime”) and “referenceDateTime” is added as an additional element • (new) CalendarType • Recommendation: Verfify, if temporal reference systems as defined in ISO 19108 (and GML/ISO 19136) are insufficient for WMO; if yes, create a metadata extension according to the rules; if no, delete this element GI standards and the WIS - Clemens Portele - 11.09.2005 42

  43. Topic B.1: Consistency / potential issues of the WMO Core Profile • (68) The note regarding the “useLimitiation” text is unclear. The data type is a free text, it is unclear what ISO parameters are • Recommendation: clarify • (285) Multiple formats • Recommendation: Encode as multiple MD_Format instances – not in a single “name” element GI standards and the WIS - Clemens Portele - 11.09.2005 43

  44. Topic B.1: Consistency / potential issues of the WMO Core Profile • (new) WMO_Source (WMO centre identifier, required because currently a private, non-TCP/IP network is used, a URL is not sufficient) • Recommendation: Use the metadata extension mechanism to specify the additional element • (232) See Topic B.3 GI standards and the WIS - Clemens Portele - 11.09.2005 44

  45. Topic B.1: Consistency / potential issues of the WMO Core Profile • Other questions and recommendations: • (4) What are “standard character sets”? • (10,11) should be fixed for a particular version of the WMO Core Profile; example: “WMO Core Profile”, “0.2” • (187, 206): Do additional rules for the use and naming of coordinate reference systems exist? • (365): Do rules for unique identifiers exist? • (348,349): Does a list of well known Gazetteers exist? Are these online-accessible? GI standards and the WIS - Clemens Portele - 11.09.2005 45

  46. Topic B.2: key omissions preventing uptake of WMO data in other communities • Limited experience is available about which factors are key metadata elements and best practices to stimulate uptake of previously unknown data sets • Some recommendations: • Try to identify the questions asked by the (potential) users of other communities when looking for data that could be provided by WMO and assess whether the WMO core metadata answers the questions • Test the use of WMO core metadata using existing metadata tools, in particular how easy it is to execute the identified scenarios • Support metadata for both the initial discovery and the evaluation phase of metadata searches • Provide information in searchable registries, including codelists, thesauri, units of measurements, etc. GI standards and the WIS - Clemens Portele - 11.09.2005 46

  47. Topic B.3: Feature types, features and coverages in WMO metadata (from ISO 19109) Feature Types are defined on the schema level Real-world objects (features) are instantiated as data; coverages are features GI standards and the WIS - Clemens Portele - 11.09.2005 47

  48. Topic B.3: Feature types, features and coverages in WMO metadata Feature Catalogue and Coverage descriptions in 19115: • MD_FeatureCatalogueDescription is used to describe catalogues of feature types (not catalogues of features!) • MD_CoverageDescription and MD_ImageDescription are used to describe individual coverages / images • Some examples of potential WIS feature catalogues seem to represent individual coverages; this is not the intention of a feature catalogue • MD_CoverageDescription is not sufficient for the requirements of WMO and would need to be extended to address the requirements • It should be checked in how far MI_CoverageDescription of ISO/WD 19115-2 addresses at least some of the issues Feature GI standards and the WIS - Clemens Portele - 11.09.2005 48

  49. Topic B.3: Feature types, features and coverages in WMO metadata • Coverages are Features. Coverage types are Feature types. • Probably both descriptions (feature catalogue and coverage descriptions) are required in WIS: • It makes sense to describe the types of features (including coverages) that are provided by the WIS, otherwise potential users will have difficulties discovering the „data products“ offered through the WIS • In addition, it may also make sense to include specific coverage descriptions in the metadata, if it is expected that users may search or look for specific characteristics of the individual coverages Feature GI standards and the WIS - Clemens Portele - 11.09.2005 49

  50. Topic C: Metadata software tools(only ISO19115-based and/or Catalog Service products) • Catalog Service products (server and/or client with support for ISO 19115 metadata) • ArcIMS Metadata Server (http://www.esri.com/software/arcgis/arcims/index.html) • ESRI GIS Portal Tool Kit (http://www.esri.com/software/arcgis/gisportal-toolkit/) • Indicio (http://www.galdos.ca/services-indicio.html) • deegree Web Catalog Service (http://deegree.sourceforge.net/index.html, FREE) • sdi.suite terraCatalog (http://www.sdi-suite.de) • Cubewerx WRS (http://www.cubewerx.com/main/products/WRS.html) • RedSpider Catalog (http://www.ionicsoft.com/products/index.jsp) • These include implementations of both Application Profiles • Dedicated metadata capture tools • M3Cat (http://www.intelec.ca/technologie_a.html#m3cat) • ANZLIC Metadata Entry Tool (MET) (http://www.anzlic.org.au/metadata_MET.html; FREE; not yet available) GI standards and the WIS - Clemens Portele - 11.09.2005 50

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