gi standards and the wis - clemens portele - 11.09.2005 report on using geographic information...

GI standards and the WIS - Clemens Portele - 11.09.2005

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 © 2005 interactive instruments GmbH

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”


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.

Global InformationSystem Centre

Data Collection or Product Centre

National Centre

GISC

GISC

GISC

GISC

GISCCommunication

Cloud

NCNC

NC

NC

NC

NC

NC NC

NC

NC

NC

DCPC

DCPC

DCPC

DCPC


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


WIS tasks (simplified)

NodeConsumer

(Client) Retrieve dataSubscribe to data

Discover data (retrieve metadata)

Abstracted from the requirements, scenarios, use cases as described in [SIMDAT] Node = GISC, NC, DCPC



NodeProvider(Client) Send data

Send metadata




NodeAdmin(Client) Manage node

Monitor and control nodeManage users, data policy and billing




NodeSend data

Send metadataRequest data (returns data)

Request data (returns reference + maybe credentials)

Node




Authenticate userAuthorize user

Log actionsManage real-time data

Node

Watch subscriptons



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 documentDraft documentdocuments with high relevance (underlined)



Data quality standardsISO 19113 - Quality principlesISO 19114 - Quality evaluation proceduresISO 19138 – Data quality measures

Reference ModelISO 19101 – Reference modelISO 19101-2 – Reference model (Imagery)



Application schemas, feature catalogues, data product specificationsISO 19109 - Rules for application schemaISO 19110 - Feature cataloguing methodologyISO 19131 - Data product specification

Coverages / Imagery and gridded dataISO 19123 - Schema for coverage geometry and functions ISO 19129 - Imagery, gridded and coverage data frameworkISO 19130 - Sensor and data model for imagery and gridded data



Spatial informationISO 19107 - Spatial schemaISO 19111 - Spatial referencing by coordinatesISO 19112 - Spatial referencing by geographic identifiers

Temporal informationISO 19108 - Temporal schemaISO 19141 – Schema for moving features



Registers and registriesISO 19135 – Procedures for registration of geographic information itemsOGC Catalog ServiceebRIM Application Profile of the OGC Catalog Service (Web Registry Service)

EncodingOGC Geography Markup Language (GML) / ISO 19136ISO/TS 19139 – XML Schema implementation of ISO 19115OGC GML in JPEG 2000 for Geographic Imagery (GMLJP2)



Data Access Web ServicesOGC Web Map Server Interface (WMS) / ISO 19128OGC Web Feature Service (WFS) / ISO 19142OGC Filter Encoding / ISO 19143OGC Web Coverage Service (WCS)

PortrayalISO 19117 – PortrayalOGC Styled-Layer Descriptor



Sensors and Sensor Web EnablementOGC Sensor Observation ServiceOGC Sensor Planning ServiceOGC Sensor Alert ServiceISO 19130 - Sensor and data model for imagery and gridded data

Geographic Digital Rights Management (GeoDRM)OGC GeoDRM Reference Model


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


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


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


ISO 19115:2003 Packages

Metadata entity set

Identification

Constraint

Maintenance

Spatial representation

Reference system

Content

Distribution

Metadata extension

Application schema

Portrayal catalogue

Data quality

Extent

Citation and responsible party

Units of Measure


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


ISO WD 19115 Part 2 Packages

Metadata entity set information

<<Leaf>>

Identification information<<Leaf>>

Constraint information<<Leaf>>

Maintenance information<<Leaf>>

Spatial representation information

<<Leaf>>

Reference system information<<Leaf>>

(from ISO 19115 Metadata)

Content information<<Leaf>>

Distribution information<<Leaf>>

Metadata extension information<<Leaf>>

Application schema information<<Leaf>>

Portrayal catalogue information<<Leaf>>

Data quality information<<Leaf>>

Extent information<<Leaf>>

(from ISO 19115 Metadata)

Citation and responsible party information

<<Leaf>>

Units of Measure<<Leaf>>

Spatial representation information - Imagery

<<Leaf>>

Identification information - Imagery

<<Leaf>>

Content information - Imagery

<<Leaf>>

Data quality information - Imagery

<<Leaf>>Extent information -

Imagery

<<Leaf>>

Requirements information - Imagery

<<Leaf>>

Acquisition information - Imagery

<<Leaf>>

Citation and responsible party information - Imagery

<<Leaf>>


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


Approach of ISO/DTS 19139

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

ISO AbstractSpecification

ISO ImplementationSpecification

XMLSchema19139

Community Profile

UML19115

UML19139

UML

19139 ext

XMLSchema

19139 ext.

Adaptation

scripts

scripts

ISO ImplementationSpecification

Status: Submitted to ISO as DTS (Draft Technical Specification), but not yet published expected to be stable, but changes may still occur


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.


ISO 19119:2005 Packages

Service Model<<Leaf>>

Service Metadata

<<Leaf>>

Identification information<<Leaf>>

Records and Class Metadata

<<Leaf>>

Data quality information<<Leaf>>


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


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.


OGC Web ServicesTypical pattern of usage

PublishFind

Bind

Search Engine

InformationResources

Chain


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


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)


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


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


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


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



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



(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



(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



(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



(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



(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



(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



(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



(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



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?


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.


Topic B.3: Feature types, features and coverages in WMO metadata

Feature Types are defined on the schema level

Real-world objects (features) are

instantiated as data; coverages are features

(from ISO 19109)



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



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


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)


Topic D: Identify high level “road map”

A high level “road map” for implementing a standards-based metadata system to achieve the goals of WIS depends on the time frame, available resources and other constraints and conditions

In general, an iterative, spiral development approach with manageable steps, gradually increasing scope and prompt validation is highly recommended


Topic D: Identify high level “road map”

Possible steps (based on discussions that led to this report):

Define scenarios and test cases for the metadata system Scenarios for (meteorology/climatology) experts Scenarios for other users with less know-how ...

Review and update WMO Core ProfileClarify conformance issuesIdentify issues in the standards that do not address the WMO metadata requirements and report them and/or define WMO specific extensions (including ISO 19111, ISO 19108, ISO 19123)

Develop mapping to 19139

Set up Catalog Service serving the metadata

Execute test cases

Review results and update specifications / add additional or more detailed specifications


Contact Information

Clemens Porteleinteractive instruments GmbH

Trierer Straße 70-7253115 BonnGermany

+49 228 91410 73 [email protected] http://www.interactive-instruments.de/


References

[SIMDAT] SIMDAT Project Deliverable D18.1.1 „Consolidated Meteorology Requirements“, Version 1.1, 25.02.2005

[WMOCore] WMO Core Metadata Profile of ISO 19115, Version 0.2, August 2004

[WMOCoreXML] WMO Core Metadata Profile of ISO 19115, Version 0.2, August 2004

[HMMG] ISO/TC 211 Harmonized Model (http://www.isoct211.org/hmmg)

[19101] ISO 19101:2002 (http://www.iso.ch/)

[19101-2] ISO WD 19101-2.3 (ISO/TC211/N1737), 16.08.2004[19108] ISO 19108:2002 (http://www.iso.ch/)



[19111] ISO/DIS 19111 rev. (sent to ISO Central Secretariat)


References


[19115-2] ISO WD 19115-2.3 (ISO/TC211/N1697), 20.08.2004[19117] ISO 19117:2005 (http://www.iso.ch/)



[19129] ISO WD 19129 (ISO/TC211/N1869), 14.7.2005[19130] ISO CD 19130.2 (ISO/TC211/N1772), 21.01.2005[19135] ISO 19135 (sent to ISO Central Secretariat)[19139] ISO/DTS 19139 (sent to ISO Central Secretariat)[CAT] OGC Catalogue Service, OGC 04-021r2 [WRS] ebRIM Application Profile of [CAT], OGC 04-017r1[CATAP] ISO 19115/19119 Application Profile of [CAT], OGC

04-038r2[GMLJP2] GML in JPEG 2000 for Geographic Imagery, OGC 05-

047r2


References

[WMS] Web Map Service 1.3, OGC 04-024 [WFS] Web Feature Service 1.1, OGC 04-094 [WCS] Web Coverage Service 1.0, OGC 03-065r6 [FES] Filter Encoding 1.1, OGC 04-095[GML] Geography Markup Language 3.1, OGC 03-105r1[OWS3] OGC Web Services Phase 3 initiative

(http://www.opengeospatial.org/initiatives/?iid=162)

[GALEON] OGC GALEON WCS Interoperability Experiment (http://www.opengeospatial.org/initiatives/?iid=173)

[SAS] OGC Sensor Alert Service Interoperability Experiment (http://www.opengeospatial.org/initiatives/?iid=149)

[SWE] Sensor Web Enablement White Paper (http://portal.opengeospatial.org/files/?artifact_id=6208&version=2&format=pdf)

gi standards and the wis - clemens portele - 11.09.2005 report on using geographic information...

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