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  • 1. Edinburgh University Data Library Geographic Information Standards Final Report Document Title Geographic Information Standards Interim Report Status Final Pages Document Revision 2.5 No. Last Modification 08/08/05 Authors Chris Higgins, Anne Robertson, Guy McGarva Contact: Dr David Medyckyj-Scott Research and Geo-data Services Manager EDINA University of Edinburgh George Square Edinburgh EH8 9LJ e-mail: d.medyckyj-scott@ed.ac.uk
  • 2. Version changes to this document Revision Date Changes Details 1.0 7 Dec 2004 CIH JISC Visit 2.0 26 Jan 2005 CIH JISC Visit 2.1 18 Apr 2005 AR Recommence 2.2 2 May 2005 AR Feedback following internal review 2.3 12 May 2005 AR Final Edits 2.4 01 July 2005 AR Executive Summary added 2.5 8 Aug 2005 AR Preface added Preface by Current Chair JISC Geospatial Data Working Group -2-
  • 3. It seems entirely appropriate to think of this report as a map. Through one privileged view, all readers can observe the same intricate relationships of numerous elements. This reconnaissance makes specific recommendations that we would do well to heed, recommendations which have been reviewed and endorsed by JISC’s Geospatial Data Working Group. Over and above the concrete recommendations, this report implies three critical actions: indeed without these actions the detail of the recommendations will be lost. Firstly, the report makes it clear that geographic information standards have been the subject of collaborative and sustained development in the last decade. For example, 22 of the 41 standards it lists are developmental. This report really cannot be the last word on Geographic Information Standards for higher and further education: it will need regular revision. It is also a call to action. Standards without adherence are a bumptious extravagance. Support for standards should come through the firm insistence of programme managers, and appropriate provision to support compliance within existing services and resources. This may require training and advice as well financial outlay, but will bring benefits in via enhanced professionalism among staff and through practical opportunities for the manipulation and analysis of data. For example a number of standards exist for the disclosure of geospatial metadata. The authors describe a specific profile for UK higher and further education. There is evident merit in following that profile, and little excuse for ignoring the more broadly based standard upon which it is based. That is partly because those cataloguing and creating geospatial resources should be sophisticated enough to recognise good practice, and partly because of the great advantages for resource discovery and integration that come from standards–based harmonisation. Thirdly, and perhaps most importantly, the standards described here need to be taken seriously by other standards developers – even those who do not consider themselves to be involved in the creation and curation of geospatial resources. This document should be a compulsory reference work in all discussions of the JISC IE and allied initiatives. The geographic information community presents a microcosm of many of the ambitions of the JISC and its partners. What might be merely an aspiration in some elements of JISC’s work – vocabulary crosswalks between information communities; interoperability beyond resource discovery; self propelled standards development – all of these have already been achieved with geospatial resources. The perception that geospatial data is a specialised niche does harm to those concerned with geospatial information, but arguably it does greater harm to those outside that community. That perception is not helped by the obscure language in which geospatial information is often presented, a jargon that frequently seems more designed to impress than inform. In commending this report I am pleased to note that it is both comprehensive and comprehensible. It is my hope that this report extends and deepens our dialogue on the opportunities afforded by a standards-based approach to information resources. The metaphor of a map is fitting for this report. Now we have the map, it is time to plan the journey. William Kilbride University of York Chair of JISC Geospatial Data Working Group Contents -3-
  • 4. 1. INTRODUCTION................................................................................................7 2. TOWARDS INTEROPERABILITY OF DATA AND SERVICES........................7 3. KEY GEOSPATIAL STANDARDS ORGANISATIONS.....................................8 4. TRENDS IN GEOSPATIAL STANDARDS DEVELOPMENT..........................11 5. GEOSPATIAL STANDARDS RELEVANT TO CREATORS AND USERS OF DATA....................................................................................................................14 5.1 Metadata and Catalogue Access............................................................................................................14 5.2 Data and Data Access.............................................................................................................................16 5.2.1 Feature Data......................................................................................................................................17 5.2.2 Coverage Data...................................................................................................................................19 5.2.3 Curation and Preservation Standards for Geospatial Data................................................................19 5.3 Maps and Visualisation..........................................................................................................................19 5.4 Spatial Reference Systems......................................................................................................................19 5.5 Geoprocessing Services...........................................................................................................................20 6. GEOSPATIAL STANDARDS RELEVANT TO OTHER JISC SERVICES......20 6.1 Metadata and Catalogue Access............................................................................................................21 6.2 Data and Data Access.............................................................................................................................22 6.3 Maps and Visualisation..........................................................................................................................22 6.4 Spatial Reference Systems......................................................................................................................23 6.5 Geoprocessing Services...........................................................................................................................23 7. GEOSPATIAL STANDARDS RELEVANT TO INSTITUTIONS......................25 7.1 Metadata and Catalogue Access............................................................................................................25 7.2 Data and Data Access ............................................................................................................................25 7.3 Maps and Visualisation..........................................................................................................................25 7.4 Spatial Reference Systems......................................................................................................................25 7.5 Geoprocessing Services...........................................................................................................................25 8. OTHER GEOSPATIAL STANDARDS.............................................................26 -4-
  • 5. 9. SUMMARY........................................................................................................28 APPENDIX A - PARTITIONING THE GI STANDARDS LANDSCAPE.............30 APPENDIX B - OTHER RELEVANT STANDARDS ORGANISATIONS...........33 APPENDIX C - INFORMATION ENVIRONMENTS............................................34 APPENDIX D - REFERENCES...........................................................................37 Executive Summary During 2003/4, EDINA was commissioned to undertake a Geodata Standards consultancy for the Joint Information Systems Committee (JISC) London office. This consultancy was to track the developments in the area of geodata standards and produce a report to inform the JISC’s strategy for Geospatial data. The report identifies those standards of most relevance to the JISC, the JISC IE and the HE/FE community and makes recommendations for future activity and priorities in this area. The report deals with trends in geospatial standards development according to three broad groups: 1. users and creators of data; 2. other JISC services; 3. institutions. The report recognizes geographic information (GI) is in the process of becoming more mainstream with respect to the IT industry. Consequently, the tendency is for GI standards to be either built on, or be highly compatible with, standards produced by organisations such as W3C, OASIS, IETF for example SOAP, XML, WSDL, UDDI. The Open Geospatial Consortium (OGC) is recognized as the key organisation involved in setting GI standards. OGC’s formal liaisons with the mainstream Information and Communication Technology systems standards bodies are described. Recommendations made are directed at each of the broad groups described above, however several themes are common:  all OGC specifications are public, free of charge and non-proprietary. Wherever possible, OGC specifications should be adopted;  the growing trend in today’s geospatial standards development environment is towards standards having relevance in service oriented architectures. Data users, creators, institutions and JISC services should consider this trend when considering strategies for data access and curation. However, the shift towards an SOA approach is hindered by immaturity and a lack of investment in web services infrastructure by JISC;  metadata creators within the HE/FE community must conform to ISO 19115. They should create metadata compliant to the HE/FE profile of ISO 19115. However, if the HE/ FE profile is not suitable, another profile of ISO 19115 should be used;  the trend towards service-oriented geospatial standards holds great potential for other JISC services to leverage GI. Geospatial standards align well with generic Information Community interoperable standards development and therefore JISC should encourage the take up of geospatial services by other JISC services as a precedent for their shared services programme. Grid computing is considered the natural foundation for future geoprocessing services. -5-
  • 6. In conclusion, JISC: • are advised to encourage the capture of geospatial metadata compliant with the HE/FE profile of ISO 19115; • should require geospatial service provides e.g. EDINA and MIMAS to provide WMS and where appropriate WFS and WCS; • should commit to the long term vision of a vibrant higher and further education SDI as described by Higgins et al (2003). Initially this can be achieved through ongoing support of its various geo-initiatives e.g. Go-Geo! and geoXwalk; • should keep a watching brief on the progression of geospatial standards related to geoprocessing services as these continue to evolve and concomitantly their relevance to activities within the UK academic Information Community increases. -6-
  • 7. 1. Introduction During 2003/4, EDINA was commissioned to undertake a Geodata Standards consultancy for the Joint Information Systems Committee (JISC) London office. This consultancy was to track the developments in the area of geodata standards and produce a report to inform the JISC’s strategy for Geospatial data. The report identifies those standards of most relevance to the JISC, the JISC IE and the HE/FE community and makes recommendations for future activity and priorities in this area. The report introduces general trends in geospatial standards development according to three broad groups:  users and creators of data;  other JISC services;  institutions. The report then provides a description of geospatial standards again for these groups under the following headings, (explained in Appendix A): o metadata and catalogue access; o data and data access; o maps and visualization; o spatial reference systems and o geoprocessing services. The report provides a high level overview of each standard. For those readers wanting detailed knowledge, the relevant standards body should be consulted directly. Also, the reader should note that the content of this document is dynamic, new standards will be incorporated as they are published. We begin by listing the key geospatial standards organizations. 2.Towards Interoperability of Data and Services The Declaration of Principles from the World Summit on the Information Society [1] concluded in paragraph 44: Standardization is one of the essential building blocks of the Information Society. There should be particular emphasis on the development and adoption of international standards. The development and use of open, interoperable, non-discriminatory and demand-driven standards that take into account needs of users and consumers is a basic element for the development and greater diffusion of ICTs and more affordable access to them, particularly in developing countries. International standards aim to create an environment where consumers can access services worldwide regardless of underlying technology. In recent years, a principal driver in the development of GI standards has been spatial data infrastructures (SDIs). More formally, a Spatial Data Infrastructure (SDI) may be defined as: “the relevant base collection of technologies, policies and institutional arrangements that facilitate the availability of and access to spatial data”, (Nebert 2001) [2]. More fully, an SDI hosts geospatial data and metadata, provides a means of discovering and evaluating the data, provides methods to access the data and establishes the necessary licensing agreements between stakeholders to make use of the data. There is an increasing recognition, that in a knowledge based economy, the effective use of GI is of critical importance. The tendency is now for mainstream COTS data management tools to, by default, incorporate the means to handle and process such data. Consequently, the exploitation of geospatial data within -7-
  • 8. diverse policy environments allied with the increasing attention being afforded to cross discipline social and environmental issues has led, inevitably, to the promotion of infrastructures for the discovery, dissemination and exploitation of geospatial data assets. Significant resources are being channelled into SDI development at the global, regional (European) and national level quite simply because much information has a reference to location. Within the academic sector it is being realised that the power of geographic information and location is under utilised - location can be used to improve our ability to find information resources and spatial information can help us analyse and visualise situations geographically. Much investment is being made by JISC in spatial data. A high level of return on this investment is possible by increasing the use of geospatial data and services e.g. a postcode look up service; maps as backdrops to data visualisation in other services; maps as access points to information (for example searching for information about archaeological monuments via a map interface on the Historic Environment Information Resources Portal at the Archaeological Data Service [3]) or potential new types of services such using PDAs in the field to record the locations of biological records. Reid et al (2004) [4] propose the UK academic community is well placed to develop a community specific SDI due to the HFE benefiting from complete access to national coverage framework data, policies developed by the JISC, standards and technical infrastructure either in place or being developed. 3.Key Geospatial Standards Organisations Geographic information (GI) is in the process of becoming more mainstream with respect to the IT industry. Consequently, the tendency is for GI standards to be either built on, or be highly compatible with, standards produced by organisations such as W3C, OASIS, IEEE, IETF for example SOAP, XML, WSDL, UDDI. All of the key organisations involved in setting GI standards maintain formal liaisons with the mainstream Information and Communication Technology systems standards bodies. International Organization for Standardization (ISO) ISO is a Non Government Organisation established in 1947 and based in Geneva. It is based upon national membership and has 147 participating countries. In relation to GI standards, the most important committee is ISO TC/211 Geographic Information/Geomatics [5], this committee is responsible for the ISO 19000 series of standards and has as its objectives: • To support the understanding and usage of geographic information • To increase the availability, access, integration, and sharing of geographic information • Enable inter-operability of geospatially enabled computer systems • To contribute to a unified approach to addressing global ecological and humanitarian problems • To ease the establishment of geospatial infrastructures on local, regional and global level • To contribute to sustainable development OpenGeospatial Consortium The Open Geospatial Consortium (OGC) has been the most active geospatial standardization body in recent years and has proposed many standards that have subsequently been adopted by ISO. The OGC [6] is an international industry consortium established in 1994. It consists of approximately 279 companies, government agencies and universities (EDINA has been a member since 2000) participating in a consensus process to develop publicly available interface specifications. OGC specifications support interoperable solutions that "geo-enable" the Web, wireless and location-based services, and mainstream IT. The OGC functions through the operation of 3 programmes: -8-
  • 9. 1. Through the Technical and Planning Committee the Specification Development Program works in a formal consensus process similar to other industry consortia, e.g. W3C, to arrive at approved Specifications. 2. The Interoperability Program is a series of hands-on engineering initiatives engaged in by OGC members to accelerate the development and acceptance of Specifications. 3. The Outreach and Community Adoption Program participates in awareness raising, education and training activities. The standards tracks of OGC and ISO are fully coordinated through shared personnel and through various resolutions of ISO TC211 and OGC. They are often complementary and where they overlap, there is no competition, but common action. Through OGC's cooperative relationship with ISO, many of OGC's Specifications either have become ISO standards or are on track to become ISO standards as illustrated in Table 1. Table 1: Roadmap of ISO and OGC standards1 Key: Published standard Standard under development Status ISO standard ISO standard name OGC specification number International Standard to be revised: ISO 6709:1983 Standard representation of latitude, longitude and altitude for geographic point locations ISO 19111:2003 Geographic information -- Spatial OGC Abstract Specification Topic 2, Spatial referencing referencing by coordinates by coordinates – submitted to ISO as proposed revision to ISO 19111. International Standard under periodical review: ISO 19105:2000 Geographic information -- Conformance and testing International Standard published: ISO 19101:2002 Geographic information -- OGC Abstract Specification Topic 7: The Earth Imagery Reference model Case implements parts of ISO 19101 ISO 19106:2004 Geographic information -- Profiles ISO 19107:2003 Geographic information -- Spatial OGC Abstract Specification Topic 1 – Feature Geometry schema ISO 19108:2002 Geographic information -- Temporal schema ISO 19110:2005 Geographic information -- Methodology for feature cataloguing ISO 19112:2003 Geographic information -- Spatial referencing by geographic identifiers ISO 19113:2002 Geographic information -- Quality principles ISO 19114:2003 Geographic information -- Quality evaluation procedures ISO 19115:2003 Geographic information -- Metadata ISO 19116:2004 Geographic information -- Positioning services ISO 19119:2005 Geographic information -- Services OGC Abstract Specification Topic 12 – The OpenGIS Service Architecture 1 Source: Current , as at 2 nd May 2005 http://www.iso.org/iso/en/CatalogueListPage.CatalogueList? COMMID=4637&scopelist=ALL -9-
  • 10. ISO/TR 19120:2001 Geographic information -- Functional standards ISO/TR 19121:2000 Geographic information -- Imagery and gridded data ISO/TR 19122:2004 Geographic information / Geomatics -- Qualification and certification of personnel ISO 19125-1:2004 Geographic information -- Simple OGC Simple Feature Access Common Architecture feature access -- Part 1: Common architecture ISO 19125-2:2004 Geographic information -- Simple OGC Simple Feature Access for SQL feature access -- Part 2: SQL option International Standard under publication: ISO 19109 Geographic information -- Rules for application schema ISO 19117 Geographic information -- OGC Styled Layer Descriptor – work to align with ISO Portrayal 19117 ongoing Final Draft International Standard ballot initiated: 2 months. Proof sent to secretariat: ISO/PRF TS 19127 Geographic information -- Geodetic codes and parameters Final Draft International Standard registered for formal approval ISO/PRF TS 19103 Geographic information -- Conceptual schema language ISO/PRF 19118 Geographic information -- GML is compliant to 19118 Encoding ISO/FDIS 19123 Geographic information -- Schema for coverage geometry and functions ISO/PRF 19133 Geographic information -- Location based services tracking and navigation Full report circulated: Draft International Standard approved for registration as Final Draft International Standard: ISO/DIS 19104 Geographic information -- Terminology ISO/DIS 19135 Geographic information -- Procedures for registration of items of geographic information Voting summary dispatched: ISO/DIS 19128 Geographic information -- Web OGC Web Map Service map server interface Draft International Standard ballot initiated: 5 months ISO/DIS 19137 Geographic information -- Generally used profiles of the spatial schema and of similar important other schemas Committee Draft approved for registration as Draft International Standard ISO/CD 19131 Geographic information -- Data product specification Comments/voting summary circulated ISO/CD 19134 Geographic information -- Multimodal location based services for routing and navigation ISO/CD 19136 Geographic information -- OGC Geography Markup Language Geography Markup Language (GML) ISO/CD TS 19138 Geographic information -- Data quality measures Committee draft study/ballot initiated ISO/CD 19111 Geographic information -- Spatial OGC Abstract Specification Topic 2, Spatial referencing - 10 -
  • 11. revises referencing by coordinates by coordinates – submitted to ISO as proposed revision ISO 19111:2003 to ISO 19111. ISO/CD 19130 Geographic information -- Sensor and data models for imagery and gridded data ISO/CD TS 19139 Geographic information -- Metadata -- XML schema implementation Working draft study initiated ISO/WD 19101-2 Geographic information -- Reference model -- Part 2: Imagery ISO/WD 19115-2 Geographic information -- Metadata -- Part 2: Extensions for imagery and gridded data ISO/WD 19141 Geographic information -- Schema for moving features New project approved ISO/NP 19132 Geographic information -- Reference model -- Location based services framework OGC work intersects other Information and Communication Technology systems standards bodies including OASIS, IETF and OMG in the following ways:  OGC is a voting member of OASIS. OGC’s CTO is the OGC OASIS Technical Representative and gets to vote on all OASIS adoption votes;  OGC CTO is member of IETF GeoPRIV working group;  OGC CTO is OGC representative to OMG. Recommendation 1: All OGC specifications are public, free of charge and non- proprietary. Wherever possible, OGC specifications should be adopted.2 4.Trends in Geospatial Standards Development The general trend in geospatial standards development today is towards the use of open, interoperable, non-discriminatory and demand-driven standards that take into account the needs of users and consumers. Increasingly, these standards have relevance within a services oriented architecture (SOA) whereby software functionalities are represented as discoverable services on a network. By focusing on an SOA, the vision of ‘create once, use often’ is being enabled. For the user/creator of geographic data, the following trends are important: - an international standard for metadata to describe geographic information now exists. ISO 19115 International Standard for Geographic Information Metadata defines the schema required for describing geographic information and services. It provides information about the identification, extent, quality, spatial and temporal schema, spatial reference and distribution of digital geographic data. In the UK HE/FE sector, the HE/FE metadata application profile of ISO 19115 has been created to meet the needs of the HE/ FE community as part of the JISC funded Geo-Data Browser (Go-Geo!) projects. Metadata created within the HE/FE should adhere to the HE/FE metadata application profile of ISO 19115. - Users/creators of geographic information can receive pictures of maps live to their desktop and/or web browser applications for use as background information and for simple querying. Portrayal services take one or more inputs and render output as cartographically portrayed maps, perspective views of terrain, annotated images or views of dynamically changing features in space and time. The OGC Web Map Server 2 British Standards Institution and the European Committee for Standardization (described in Appendix B) evaluate standards developed by ISO/TC 211, and decide on their suitability for adoption in their jurisdication. - 11 -
  • 12. specification (WMS) is a set of protocols that provide access by clients to maps rendered by map servers on the Internet. This is of particular value to user/creators of data as it: o reduces data latency and o reduces the need for local data storage and management when a picture of data is all that is required e.g. as a backdrop image, as a general geographic reference. Imagine the scenario whereby a student is mapping health data onto census boundaries. As a visual backdrop to their work, they also require property boundaries. Property information is inherently large and dynamic – changing daily. A WMS service of property boundary data would enable the student to obtain a transparent image of property boundaries to overlay with their locally stored health boundaries and even label each property with address information. - If portrayal services provide pictures of data, data services provide access to raw geographic feature data. The OGC Web Feature Service Specification (WFS) supports the query and discovery of geographic features and attributes. In a typical web-based scenario, WFS delivers Geography Markup Language (GML) representations of simple geospatial features in response to queries from HTTP clients. In the scenario above, the student may need to access the exact spatial coordinates of a large rural property boundary to then intersect that geographic feature, with another, say a water catchment boundary. A WFS of property boundaries would provide that level of granularity. - Users/creators of data should be aware that Geography Markup Language (GML) is an XML encoding for the transport and storage of geographic information, including both the geometry and properties of geographic features. Some data providers, for example the Ordnance Survey are making data available in GML. For other JISC services, the trend of service-oriented geospatial standards offers huge potential for service enhancement. Today’s geospatial standards align well with those web service standards and protocols that exist within any information community, including the JISC IE. - Just like the data user/creator can benefit from a picture of a map provided by a portrayal service as described above, so any JISC service can be visually enhanced with over-layed images of geographic information (e.g. an aerial photograph with census districts and school locations) by issuing simple HTTP GetMap requests as described in the WMS specification. Leveraging the WMS specification enables other JISC services to be enhanced with current images of maps (most commonly PNG, GIF or JPEG) from a myriad of different content providers using simple HTTP requests without having to know geo-specific information e.g. the format or coordinate systems of the source data. - Data services will enhance JISC services to a greater granularity. By defining additional behaviour and formalizing response elements, the WFS specification can be extended to a Gazetteer service. A Gazetteer is a list of features containing some information regarding position, at it’s most simple, a list of place names and their associated geometries. The queryable feature attributes are the place names and the returned features are the geometries. Hence within the JISC IE, a gazetteer service would accept a list of place names and return their matched coordinates. Indeed, the principal purpose of geoXwalk [7], within the JISC IE, is to develop a demonstrator gazetteer service for the purpose of enhancing geographic searching within the JISC IE. This service is of particular value when it’s chained to another, e.g. a portrayal service, where the returned coordinates are mapped as points, merged with other map data and presented as a new image to the client. - There are other geoprocessing services, which have not yet been ratified as international standards that, if implemented, will enrich service offerings within the JISC IE. Geocoding is the process of linking words, terms and codes found in a text string to their applicable geospatial features, with known locations defined as geometry. Geoparsing refers to the capability to process a textual document and identify key words and phrases that have a spatial context. Geolinking is taking attribute data which refers to spatial features, and joining to a geospatial dataset, that can then be mapped. Such core services fit well within the JISC IE Shared Services model. Discussions around - 12 -
  • 13. progressing these concepts into specifications are ongoing within the OGC. EDINA’s membership of OGC ensures JISC visibility and progress on these discussions. - JISC’s Information Environment Service Registry (IESR) aims to make it easier for other applications to discover and use materials within the JISC IE, as a machine-to-machine service. Within the GI landscape, Catalogue Services provide a common mechanism to classify, register, describe, search, maintain and access information about resources available on a network. The OGC Catalog Interface Specification describes the interfaces, bindings and a framework for defining application profiles required to publish and access digital catalogues of metadata for geospatial content, services and related resource information. It is beyond the scope of this document to compare and contrast strategies for IESR development versus the OGC Catalog specification. Indeed, if the vision for IESR is met, relevance of the OGC catalog specification within the JISC IE may be minimal. The role of the institution is varied within this discussion, indeed the collective term ‘institution’ could equally be interjected with department or school or research team. The following are true for all: - institutions should adopt and encourage the use of the HE/FE metadata profile of ISO 19115; - if there is an intention to store geographic data and ensure it’s long-term reuse, institutions may consider storing geographic data as GML. Conformance Testing The most noticeable trends in geospatial standards development have been described above. The issue of compliance to, and implementation of, these standards is relevant. Validating conformance to an OGC Specification means verifying that a software product has implemented the specification correctly. Validation involves testing the software interface for response and behaviour outlined in the specification. The Conformance and Interoperability Test and Evaluation (CITE) Initiative has provided the geospatial industry (customers and vendors) with a methodology and tools for testing products' conformance to OGC Web Services specifications and for determining whether products that conform are interoperable with one another. Very importantly, CITE also produced conformance tests for WMS and WFS. In addition, CITE produced a conformance engine (a platform for developing tests), a GML validator, scripts and guidelines, and a CITE Portal [8] with links to Websites that implement the official OGC reference implementations of WMS and WFS. The OGC web site also maintains a registry of registered software products that have been tested to comply to or claim to implement OGC specifications [9]. Digital Rights Management Digital Rights Management (DRM) is a general term for technologies established to protect Intellectual Property (IP) assets through digital distribution networks. DRM is about creating, packaging, distributing, controlling and tracking content based on rights and licensing information. There is as yet no open standard that deals directly with DRM within the geographic sector 3. It is widely accepted that the absence of a DRM capability is a major barrier to the broader adoption of Web based geospatial technologies and in June 2004 the OGC formed the GeoDRM Working Group to “coordinate and mature the development and validation of work being done on digital rights management for the geospatial community.“ A system of operating agreements, interoperable technologies and authentication is needed to enable broader distribution, and use of geodata while protecting the rights of producers and users. If the absence of a DRM capability is seen as a major barrier to the broader adoption of web based geospatial technologies, then a general level of immaturity combined with a lack of direct investment in web services within JISC outwith projects must be seen as hindering the shift to an SOA approach. Two examples are pertinent. 3 the closest is the OGC Web Pricing and Ordering System (WPOS) discussion paper. - 13 -
  • 14. o Within the academic community the relevance of access and authentication to the take- up of web based geospatial technologies is paramount. Athens is an information security technology and the current de facto standard for secure access to management to web-based services within the UK academic sector. However, Athens does not support web services. There seems no cohesive solution to this problem and EDINA are currently designing their own methods for Athens users to be able to access geospatial web services (WMS) from their desktops based upon cookies. o The JISC Information Environment Services Registry (IESR) is a single central registry of JISC services designed to be accessed by other applications as a machine-to- machine service. The IESR can currently be accessed via Z39.50, however future development of a UDDI view of the IESR is unclear (UDDI is considered a common component of the interoperable architecture stack for service discovery). Recommendation 2: The growing trend in today’s geospatial standards development environment is towards standards having relevance in service oriented architectures. Data users, creators, institutions and JISC services should consider this trend when considering strategies for data access and curation. However, the shift towards an SOA approach is hindered by immaturity and a lack of investment in web services infrastructure by JISC. 5.Geospatial Standards Relevant to Creators and Users of Data Note: detailed descriptions of service-based specifications (including WMS and WFS) are located under section 5 – geospatial standards relevant to other JISC services. Users and creators of geospatial data demonstrate the following broad characteristics: • increasingly, data creators are encouraged to consider the reuse of data through the terms and conditions of funding; • users and creators of data have a myriad of tools available to interact with geospatial data (conventional desktop GIS applications, programming languages, html clients, web interfaces). With these characteristics in mind, the following geospatial standards are of relevance. 5.1Metadata and Catalogue Access Metadata is the technical word for 'data about data'. It is the term used to describe the summary information or characteristics of a set of data. In the area of GI, (or information with a geographic component e.g. a postcode or placename), this normally means the What?, Who?, When?, How? and Where? of the data. The only major difference between geographic metadata and the many other metadata sets being created for libraries, academia, professions, etc, is the emphasis on the spatial component - the 'where' element. Metadata standards and consistency are necessary to ensure that comparisons can be made by users about the suitability of data from different sources. This means, for example, when comparing metadata about property or hazardous waste there is an indication of the dates to which the information refers, or if comparing metadata about different map sources the relevant scales are shown. Without standards endorsed validated metadata, meaningful comparisons cannot be made. The importance of creating standardised metadata to describe geospatial datasets has been recognised for many years (e.g. Medyckyj-Scott et al, 1989) [10]. Metadata for geographic information is required for a range of purposes and includes: - 14 -
  • 15. • detailed information about data collection methods, integration and analysis techniques applied to various components of source data to support the preparation of scientific reports; • information about the accuracy of source datasets, processing history, and archival procedures to effectively manage and utilise data within custodian organisations; • information about the spatial reference system including projection specifications, scale, and a data dictionary to accompany data transfers to other organisations; • adequate descriptions of the content, quality and geographic extent of datasets so potential users of existing data can assess its suitability for other purposes; • summary descriptions of content and quality as well as contact information for inclusion in directory systems. There is significant overlap in the type of information required for the above purposes. Data quality information is required for most purposes, but the degree of detail necessary varies. The metadata elements required to adequately describe different types of data also vary. For instance, some of the elements relevant to the description of climatic datasets are not relevant to the description of geoscience or marine datasets. The most detailed metadata and range of elements are required for data management purposes within custodian organisations. In the context of data discovery, the metadata provided needs to be enough to convey to the user the nature and content of the data and give some indication of fitness for purpose. Over the years many geospatial data specific metadata standards have been proposed and implemented. These are described in a report by O’Hanlon, (2001) [11] produced during the JISC 5/99 funded geodata browser project. That report recommended the use of Content Standard for Digital Geospatial Metadata (CSDGM) produced by the US Federal Geographic Data Committee (FGDC) – see below. However the report noted that work was underway on an ISO standard. The core metadata standard for geospatial data is now ISO 19115 Geographic Information – Metadata. ISO 19115 Geographic Information – Metadata (and ISO 19139 Metadata – Implementation Specification) The objective of this International Standard is to provide a clear procedure for the description of digital geographic datasets so that users will be able to determine whether the data in a holding will be of use to them and how to access the data. This standard for the implementation and documentation of metadata furnishes those unfamiliar with geographic data the appropriate information to characterise their geographic data and it makes possible dataset cataloguing enabling data discovery, retrieval and reuse. It is relevant to highlight that ISO 19139 is an implementation of the ISO 19115 dataset metadata application profile presented as an annex of ISO 19115. ISO 19139 is designed to provide a common specification for describing, validating and exchanging metadata about geographic datasets. It is intended to promote interoperability, and exploit ISO 19115’s advantages in a concrete implementation specification. A profile is a subset of one or several information standards which adopts elements, structures or rules for different user communities. The following profiles are relevant: The Higher Education/Further Education (HE/FE) Metadata Application Profile of ISO 19115 The HE/FE profile of ISO 19115 has been developed by EDINA as part of the JISC funded Go- Geo! project [12]. (Go-Geo! is an online resource discovery tool which allows for the identification and retrieval of records describing the content, quality, condition and other characteristics of geospatial data that exist within UK tertiary education and beyond.) The HE/FE profile is designed to support the documentation and discovery of geospatial datasets within Higher and Further Education. The Profile comprises 92 elements. This number of elements is attributed to several factors: delivery of an HFE profile which supports geospatial dataset documentation across an eclectic academic community; recognition of the need to meet data management and sharing requirements within academia; and compliance with the new ISO 19115 geospatial metadata standard and ISO 19115 compliant UK GEMINI (see next section), which was ratified - 15 -
  • 16. last year and supersedes the standards used by NGDF and GIgateway standards for the UK. Combined, the elements provide the academic user with the information necessary to assess the dataset type, its location, quality and completeness, temporal aspects in terms of data collection and content, and the necessary contact details to enquire further about access and use. The Profile has also been cross-mapped to other relevant standards. These include UK GEMINI, ISO 19115 geo-spatial metadata standard, the FGDC’s Content Standard for Digital Geospatial Metadata (CSDGM), the Data Documentation Initiative standard, the e-Government Metadata Standard (eGMS) and Dublin Core. These mappings were done to assess compatibility, and address interoperability and harmonisation between standards to improve cross-searching capabilities. In support of the Profile, a guidelines document has been written to serve as a reference resource for individuals and organisations wishing to document and create metadata records for their geo-referenced datasets. Use of the guidelines can also ensure the creation of compliant metadata for the Go-Geo! portal site or to aid in the management of internal datasets. The Profile Guidelines also represent a critical resource for maintaining metadata quality assurance and currency. UK Geospatial Metadata Interoperability Initiative (UK GEMINI) Beyond the academic community, the UK GEMINI profile provides adherence to ISO 19115 and the national e-Government Metadata Standard4. The UK GEMINI standard was launched in October 2004 and is the result of collaboration between the Association for Geographic Information AGI [13], the Cabinet Office e-Government Unit [14] and the UK Data Archive at the University of Essex [15]. Full details on the UK GEMINI Profile can be accessed at www.gigateway.co.uk/metadata/standards.html. A mapping has been produced by the Go-Geo! team from the HE/FE Metadata Application Profile to GEMINI to support metadata interoperability. Federal Geographic Data Committee Content Standard for Digital Geospatial Metadata (FGDC CSDGM) The FGDC [16] is a multi-member interagency committee composed of representatives from across US government. The FGDC CSDGM has been adopted worldwide. The adoption of this standard beyond the US is due more to US ownership of many leading GIS software vendors as opposed to any preference for the standard itself. FGDC are in the process of harmonizing the FGDC’s CSDGM with ISO 19115. The current status of this work is reported at www.fgdc.gov/metadata/whatsnew/fgdciso.html. Again, a mapping has been produced by the Go- Geo! team from the CSDGM to the HE/FE Metadata Application Profile. This is to allow legacy records created to the CSDGM standard to be converted to HE/FE Metadata Application Profile. Recommendation 3 – Metadata creators within the HE/FE community must conform to ISO 19115. They should create metadata compliant to the HE/FE profile of ISO 19115. However, if the HE/FE profile is not suitable, another profile of ISO 19115 should be used. 5.2Data and Data Access Conventional practice is to partition GI into two distinct types; 1. discrete geometries or features with associated values or attributes, and 2. fields of measured values, often termed coverages (including but not limited to earth images). The term “feature” is typically taken as referring to a discrete data entity whose position in space is described by geometric and topological primitives such as points, lines and polygons. In terms of real world objects, features correspond to the likes of; buildings, road networks, lamp posts, etc. The following standards pertain to feature data: 4 The eGMS is based on Dublin core with additional elements and refinements to meet the needs of the UK public sector. - 16 -
  • 17. 5.2.1Feature Data Geography Markup Language Geography Markup Language is recognized by the following standards bodies: ISO ISO/CD 19136 Geographic Information – Committee Stage – committee draft (CD) registered comments/voting summary circulated Geography Markup Language OGC Geography Markup Language (GML) Version 3.0 UK eGIF GML GML is an adopted eGIF standard under specifications for business areas – miscellaneous [17] The Geography Markup Language (GML) is an XML encoding in compliance with ISO 19118 for the transport and storage of geographic information modelled according to the conceptual modelling framework used in the ISO 19100 series and including both the spatial and non-spatial properties of geographic features. The objective is to provide an open, standard, meta-language for geospatial constructs so that information can be semantically shared across various domains e.g. forestry, tourism, geology. GML3.0 is an OGC implementation specification and can be downloaded from the OGC web site at https://portal.opengeospatial.org/files/?artifact_id=7174. With effect from March 2003, Ordnance Survey [18] started supplying OS MasterMap data in GML. OS claims it has aligned itself to Internet-based technologies by using GML to encode OS MasterMap data. For more information, check out www.ordnancesurvey.co.uk/oswebsite/business/sectors/wireless/news/articles/pdf/OS %20MasterMap%20in%20GML.pdf. There are also sector-specific developments in GML, for example XMML for exploration and mining data, marineXML for hydrographic data, cityXML for planners and landXML for land administration. Data users should be aware the take up of GML by GIS software vendors varies and are advised to check for compatibility if acquiring data provided in GML. UK National Transfer Format (NTF) NTF (National Transfer Format) is an implementation of British Standard BS7567 and administered by the Association for Geographic Information in the UK. For many years this has been the format used by the Ordnance Survey to supply geographic data to customers. There are a number of different profiles of NTF that supports different types of data including simple vector, complex vector and raster. As the OS moves to supplying their data in GML, the use of NTF has diminished but is still in common use for supplying their existing datasets such as Land-Line data. US Spatial Data Transfer Standard (SDTS) In the US, the Spatial Data Transfer Standard (SDTS) has been defined and is now mandatory for federal agencies and is also used by state and local governments, the private sector, and research and academic organizations. The purpose of the SDTS is to “promote and facilitate the transfer of digital spatial data between dissimilar computer systems, while preserving information meaning and minimizing the need for information external to the transfer. “[19] The Spatial Data Transfer Standard (SDTS) is implemented through the use of profiles, such as the Topological Vector Profile (TVP), the Raster Profile (RPE) and the Transportation Network Profile (TNP). SDTS is designed to support all types of spatial data. Profiles balance two objectives of SDTS, first to allow both encoding and decoding to be feasible, and second to ensure that all meaningful information is transferred. Specific data formats have been defined that adhere to the SDTS, including vector and raster data formats from the US Geological Survey (USGS). Formats include DLG (Digital Line Graph) for vector data, DEM (Digital Elevation Model) for terrain models and DOQ (Digital Orthophoto Quadrangles) for imagery data. Due to the wealth of data made freely available by US federal - 17 -
  • 18. agencies, users and creators of data within the UK may find themselves working with data provided in SDTS format. Military Standards – Digital Geographic Information Exchange Standard (DIGEST) The Digital Geographic Information Exchange Standard (DIGEST) was developed under the auspices of NATO to "support the efficient exchange of Geographic Information among nations, data providers, and data users"[20]. DIGEST is a comprehensive family of standards capable of supporting a range of geospatial data including raster, matrix and vector (including topological) data. There are a range of data format specifications based on DIGEST including VPF (Vector Product Format) defined as a US Military Standard (MIL-STD-2407). Data supplied in this format includes: - Digital Chart of the World (DCW), - Digital Nautical Chart (DNC) and - Vector Smart Map (VMap of varying levels). Raster formats are also defined that conform to DIGEST standards including DTED (Digital Terrain Elevation Data) and Arc Digitized Raster Graphics (ADRG) which is a format used for imagery data. Although the primary use of these data formats was for military purposes, much of the data produced is publicly available and widely used for reference purposes. De facto Standards Vendor specific data formats are often referred to as being de facto standards. The most common formats in use within the HE/FE community are ESRI [21] shapefiles, ESRI e00 files, AutoCad [22] DXF and MapInfo [23] mif/mid and MapInfo Native files. Much data created within or made available for use by the HE/FE community will be in one of these formats. As a long term strategy for data curation. de facto standards are not recommended. The standards discussed so far for feature data are generic across the geographic sector. However, creators/users of geographic data should be aware there are data standards within particular vertical sectors. The following examples cover the land and property and hydrographic sectors. British Standard BS7666 Spatial Datasets for Geographical Referencing British Standard BS7666 was created to facilitate the creation of the National Land and Property Gazetteer [24]. It specifies a standard format for holding details on every property and street. The standard is based on the concept of a land parcel unit. Each unit has a unique reference number, a spatial reference and one or more Land and Property Identifiers. The standard comprises four parts covering Street Gazetteers, Land and Property Gazetteers, Addresses and Rights of Way. Relevant Ordnance Survey datasets conform to this standard. All four parts of the standard are currently being revised - more details on the revision process can be found at http://www.agi.org.uk/aginews/index.htm. International Hydrographic Office (IHO) S-57 For Hydrographic Chart data, the S-57 standard has been developed. S-57 has been defined by the International Hydrographic Office [25] and is used by all Hydrographic Offices worldwide. The Electronic Nautical Chart (ENC) Application Profile, which is a subset of the full S-57 specification, has been designed for use mainly in ECDIS (Electronic Chart Display Information Systems) aboard ships. The standard includes the definition of an Object/Attribute Catalogue and also the encoding of the data which uses the ISO standard ISO/IEC 8211. The current version of S-57 is 3.1 but there are plans to develop a version 4.0 based on GML and the ISO 19100 series of standards. - 18 -
  • 19. 5.2.2Coverage Data “Coverages” are the other broad category of geospatial data: they describe the characteristics of a set of spatial locations. Examples include; soil maps (soil types at specific areas), satellite images (reflectance in various spectral bands from specific areas), or digital elevation models (regularly-spaced elevation data, or triangulated irregular spot elevations). GeoTiff GeoTiff is the de facto industry standard for storing georeferenced image data. It is based on the standard TIFF image format with extra header tags used to store various types of georeferencing information such as image extents and projection system. The GeoTIFF format [26] is open, public domain and non-proprietary. The original GeoTiff working group included large US government agencies and the major GIS software vendors including SPOT, NASA, USGS, Intergraph, ESRI and MapInfo. UK National Transfer Formats for Coverage Data There is also a specific standard for the transfer of coverage data. Digital Terrain Models are supplied by the Ordnance Survey in British Standard BS7567 (NTFv2.0) format. 5.2.3Curation and Preservation Standards for Geospatial Data The ISO standard 14721 defines the Open Archival Information System (OAIS) Reference Model as the standard for long term storage of digital information. This standard addresses the issues of preserving information over the long-term and also providing access to the archived information. Common standard data storage formats should be used for long term preservation, for example GML for vector data should be used where feasible and compressed using standard compression algorithms. Raster data should be stored using GeoTiff or other common/standard raster format suited to the type of data, again using standard compression algorithms such as LZW. Metadata standards previously identified as relevant to geospatial data should also be adhered to when considering long-term preservation. Recommendation 4 – Users and Creators of data should be aware of: the use of GML as a data transfer format and possibly as a storage format the growing trend towards the provision of data via web services the continual wealth of geospatial data available in common de facto standards (however, de facto standards are not recommended for long term data curation). 5.3Maps and Visualisation The importance of the visual portrayal of geographic data cannot be overemphasized. The skill that goes into portraying data (whether it be geographic or tabular) is what transforms raw information into an explanatory or decision-support tool. From a data creators/users perspective it is often critical, indeed it can be part of the contract between data provider and consumer, that rules for data presentation are followed. Often a data provider will provide a digital legend that should be used to present their data. Often the form of that digital legend will be specific to the software format of the data. There are no standards for the provision of digital legends per se, however colours and annotations used in legends may be described using standards e.g. RGB colours as defined in ISO IEC 61966 Colour measurement and management. 5.4Spatial Reference Systems In order to perform spatial associations, entities must be referenced to a common coordinate system. There are hundreds of coordinate systems in common use. The European Petroleum Survey Group (EPSG) maintains and publishes a data set of parameters for coordinate reference - 19 -
  • 20. system and coordinate transformation description. EPSG comprises specialist surveyors, geodesists and cartographers from oil companies based in Europe. EPSG tables are the most comprehensive available in the public domain today and are available from www.epsg.org. EPSG has category A (the most comprehensive and complete) liaison membership of ISO TC211. What prevents the establishment of a standard coordinate system for use in GIS is that the most useful coordinate systems are orthogonal (composed of axes that cross at right angles, and units that are equal in all parts of the grid) yet the earth is round and must be flattened to fit into an orthogonal coordinate system. There are many methods (projections) for making flat, orthogonal representations of the earth, but no single method will do a good job on the entire planet. So, understanding coordinate systems -- what their important qualities are, how to identify them and how to transform one into another, are very important skills for the data user and/or data creator. To this end, the spatial reference system standards, of relevance to data creators and users are: ISO 6709 – Standard representation of latitude, longitude and altitude for geographic point locations Outwith the work of ISOTC 211 this standard from the early 1980s describes a variable-length format for the representation of latitude, longitude and altitude for use in data interchange. ISO 19111 - Spatial Referencing by Coordinates Defines the conceptual schema for the description of spatial referencing by coordinates. Recommendation 5 – Users and creators of data should be aware of the existence of the European Petroleum Survey Group parameters for coordinate reference systems and refer to ISO 19111 Spatial Referencing by Coordinates for guidance. 5.5Geoprocessing Services Geoprocessing services can be viewed broadly as those services which model, interpret and use GI. Users of spatial data may take advantage of a number of geoprocessing services. Up until now, users of spatial data have used the functionality offered by their desktop GIS to model, use and interpret spatial data. However, as we move into an era of service oriented networks, GIS experts and non-traditional users of GI data will increasingly take advantage of network based geoprocessing services and grid computing(described under section 5.5). ISO 19107 – Spatial Schema Although mostly concerned with geometry and topology, ISO 19107 - Spatial Schema, provides a model of geoprocessing operators such as “buffer” or “intersects”. 6.Geospatial Standards Relevant to other JISC Services Those within the GI community, have a vision that Information Communities5, including the JISC Information Environment [27], will, where it makes business sense, seek to geographically enhance their services by leveraging geospatial services. Such enhancements will include dynamic maps as backdrops in other services, gazetteer queries, geocoding of documents held in other JISC services and the use of location to access resources. There already exists a list of the key standards and protocols that make up the JISC Information Environment (IE) technical architecture [28]. Standards are intended to apply to all JISC IE service components. Because the JISC IE aims to promote a services oriented architecture, one that represents software functionality as discoverable services on a network, the following interoperability stack (Figure 1) gives a good indication of where today’s geospatial standards sit within the context of non-geo web service standards and protocols that exist within the JISC IE. 5 For an extended list of relevant information environments refer to Appendix C - 20 -
  • 21. Interoperability Layers Interoperability Standards Service Interoperability Integration & BPEL4WS, ISO19119 Workflow Service Discovery UDDI, OGC-Catalog, etc. Service Description WSDL,ISO-19119, etc. Service OGC SF, Coverage, Coordinate Transform, WMS, etc. Binding HTTP, SOAP, COM, CORBA, SQL, J2EE, etc. Data Format, Schema and HTML, XML/S, RDF, XMI, OGC-GML, Semantics OGC-WKT/WKB, etc. Data Representation ASCII, ASN.1/DER, XML, etc. & Encoding Communication TCP/IP, HTTP, SSL, SMTP, FTP, Protocols IIOP, etc. Connectivity Figure 1: Interoperability stack with OGC specifications denoted in bold e.g. GML, WMS, Catalog [29] Figure 1 provides a useful contextual overview but it is worth considering in more detail the key geospatial standards that are of relevance to other JISC services. 6.1Metadata and Catalogue Access To leverage geospatial services, other JISC services will need to know what types of geospatial services are available, where to find them, what access constraints exist (if any) and how to communicate with them. The method of discovering available services and binding to them, is achieved via interaction with catalog services. Within the JISC IE, the Information Environment Service Registry (IESR) has been developed to provide a source of information about electronic resources and the ways in which they may be accessed [30]. The IESRI contains information about the resources themselves, technical details about how to access the resources, and contact details for the resource providers. The IESR is designed to be accessed by other applications as a machine-to-machine service. It is understood SOAP and UDDI interfaces of the IESR are planned. These future developments align well with the direction of the OGC Catalog specification. OGC Catalog Specification The OGC Catalog Specification (CAT) describes the interfaces, bindings, and a framework for defining application profiles required to publish and access digital catalogues of metadata for geospatial data, services, and related resource information. The specification is applicable to the implementation of interfaces on catalogues of a variety of information resources. The CAT provides a common architecture for online automated directories, or clearinghouses, of web- based geospatial data, data download and view services and geoprocessing services. The specification establishes a standard way to create catalog entries that describe online geospatial data and geoprocessing services and point to their urls. - 21 -
  • 22. A more detailed analysis of the IESR is required to understand how well it meets the requirements of a GI catalog. 6.2Data and Data Access OGC Web Feature Service (WFS) The OGC Web Feature Service (WFS) supports the query and discovery of geographic features and attributes. In a typical web-based scenario, WFS delivers GML representations of simple geospatial features in response to queries from HTTP clients. Clients access geographic feature data through a WFS by submitting a request for just those features that are needed for an application. The client generates a request and posts it to a WFS instance (a WFS server on the web). The WFS instance executes the request, returning the results to the client as GML. A GML-enabled client can then manipulate or operate on the returned features. OGC Web Coverage Service (WCS) The WCS specification defines a web based syntax for access to Coverage data. WCS is similar to WFS in that it allows clients to choose portions of a server's information holdings based on spatial constraints and other criteria. WCS allows access to the raw data which can then be used for further analysis or for portrayal if required. 6.3Maps and Visualisation OGC Web Map Service Implementation Specification A Web Map Service (WMS) produces maps of spatially referenced data dynamically from a GI datastore. The International Standard defines a "map" to be a portrayal of geographic information as a digital image file suitable for display on a computer screen. A map is thus not the data itself but a representation of it. WMS-produced maps are generally rendered in a pictorial format such as PNG, GIF or JPEG, or occasionally as vector-based graphical elements in Scalable Vector Graphics (SVG) or Web Computer Graphics Metafile (WebCGM) formats. When two or more maps are produced with the same geographic parameters and output size, the results can be accurately overlaid to produce a composite map (such as the example in Figure 1). The use of image formats that support transparent backgrounds (e.g., GIF or PNG) allows underlying maps to be visible. Furthermore, individual maps can be requested from different servers. The Web Map Service thus enables the creation of a network of distributed map servers from which clients can build customized maps. - 22 -
  • 23. Figure 1 showing combined hurricane image plus population map for the US [31]. OGC Web Map Context Specification This specification allows users to save complex multi-source presentations so they can be retrieved in total in the future so they do not have to be rebuilt form scratch. It is useful to be able to record the state of a WMS client application at a view of interest to a user, and then to restore that state at a later time (a kind of book-marking facility). OGC Styled Layer Descriptor Specification This specification describes how the WMS specification can be extended to allow user-defined symbolization of feature data. For example, a layer advertised by a WMS as “hydrography” may consist of lines (rivers and streams) and polygons (lakes, ponds, oceans, etc.). A user might want to tell the server to colour the insides of all polygons in a light blue, and colour the boundaries of all polygons and all lines in a darker blue. This type of styling requires no knowledge of the attributes or “feature types” of the underlying data, only a language with which to describe these styles. Today, the number of WMSs supporting SLD is fairly limited as the focus on user driven customisation of maps is still immature. Service providers require greater skills and resources to support this enhanced service. 6.4Spatial Reference Systems Other JISC services will find the ISO 19111 – Spatial Referencing by Coordinates standard of relevance particularly as some of those geoprocessing services they wish to leverage e.g. gazetteer will return their result in one or more geometries expressed in an Spatial Reference System. 6.5Geoprocessing Services Geoprocessing services can be viewed broadly as those services which model, interpret and use GI. Users of spatial data may take advantage of a number of geoprocessing services. Up until now, users of spatial data have used the functionality offered by their desktop GIS to model, use and interpret spatial data. However, as we move into an era of service oriented networks, GIS experts and non-traditional users of GI data will increasingly take advantage of network based geoprocessing services. For users and creators of data, it will be the awareness of what - 23 -
  • 24. geoprocessing services exist and what value they offer them (discovered via catalog services), as opposed to what standards they implement, that will be of value. OGC’s Coordinate Transformation Services (CT) Given the variety of coordinate systems in use, coordinate transformation (that is, re-expressing geospatial positions in a new coordinate reference system) is one of the most commonly-needed geoprocessing operations. OGC’s CTS standard provides interfaces for general positioning, coordinate systems, and coordinate transformations. Beyond the CTS specification, there are a large number of OGC discussion papers on a variety of geoprocessing services. None of these are formalised standards, nor do they represent the official position of the OGC. However, discussion paper status within the OGC does indicate technology being considered in the Working Groups of the OGC Technical Committee. Discussion of future geoprocessing services is a timely reminder of the relevance of developments in eScience. As a general point, it seems likely that to take advantage of the next generation of geoprocessing services will require greater processing power and the ability to shift increasingly large amounts of data, thus a focus on eScience. The term eScience is most often heard in association with references to The Grid. Grid Grid computing is concerned with “coordinated resource sharing and problem solving in dynamic, multi-institutional virtual organisations”. (Ian Foster, 2002, [32]). The key concept is the ability to negotiate resource-sharing arrangements among a set of participating parties (providers and consumers) and then to use the resulting resource pool for some task. Boyle et al, 2004 [33] recognize that “Given the need for easy and efficient access to the many GI datasets that exist in governmental and academic institutions, grid computing is therefore the natural foundation for establishing new capabilities for the creation and use of GI data in research and public service”. The following list6 of OGC White Papers provides examples of the types of geoprocessing services being considered within OGC that may leverage advances in grid computing. Gazetteer Service Profile of a WFS A Gazetteer is a directory of features containing some information regarding position. A Gazetteer Service is a network-accessible service that retrieves one or more features given a query request. The queryable feature attributes are any properties that describe the features, including but not limited to feature type (e.g. town, hill, river) and feature name (e.g. Edinburgh, Arthur’s Seat, Water of Leith) and the returned features will include one or more geometries. Increasingly feature or place names are the first element in searching for information about places with computer search tools that use the name of the place as the key to the archive. Such techniques have the potential to unlock a wealth of information managed by libraries, museums and national archive systems. Geocoder Geocoding is the process of linking words, terms and codes found in a text string to their applicable geospatial features, with known locations defined as geometry. Geoparser Geoparsing refers to the capability to process a textual document and identify key words and phrases that have a spatial context. Geolinking Service A Geolinking Service takes attribute data which refers to spatial features, and joins it to a geospatial dataset, so that it can be mapped by a WMS or used in a GIS. When a Geolinking 6 this is a sample list only, refer to http://www.opengeospatial.org/specs/?page=discussion for a full listing - 24 -
  • 25. Service uses data from a Geolinked Data Access Service (described below) and serves as a front end to a WMS, it enables real-time mapping of data stored in non-spatial databases. Geolinked Data Access Service A Geolinked Data Access Service (GDAS) provides a way to publish and access data that refers to spatial features (e.g. population data for countries). A GDAS can expose data from non-GIS databases so that it can be manipulated and mapped with the aid of a Geolinking Service. Recommendation 6: The trend towards service-oriented geospatial standards holds great potential for other JISC services to leverage GI. Geospatial standards align well with generic Information Community interoperable standards development and therefore JISC should encourage the take up of geospatial services by other JISC services as a precedent for their shared services programme. 7.Geospatial Standards Relevant to Institutions The following assumptions on the characteristics of institutions (or research teams, departments, or schools) have been made: - institutions are generally committed to maximizing the long-term accessibility and reusability of data created by it’s students, researchers and staff; - institutions will provide guidance on best practice geospatial standards. Taking into consideration the above assumptions, the following geospatial standards are of relevance to institutions. 7.1Metadata and Catalogue Access Institutions supporting the capture of metadata by data creators should promote the HE/FE metadata application profile of ISO19115 as described in 3.1. 7.2Data and Data Access Institutions wishing to store geospatial data in a non-proprietary format may consider using GML for feature data and GeoTIFF for coverage data. Institutions advising on sourcing data should raise awareness of data provided in GML, WFS and WCS. 7.3Maps and Visualisation Institutions providing advice on sourcing data may advise of the growing trend of data available as images to be used as background information. Institutions may also advise of the associated Web Map Context specification and Styled Layer Descriptor specification giving the user more control over data presentation and the ability to save a composite image. 7.4Spatial Reference Systems Institutions providing guidance on spatial reference systems should reference ISO 19111 spatial referencing by coordinates. 7.5Geoprocessing Services Institutions should be aware of the increasing occurrence of web based geoprocessing services. - 25 -
  • 26. Recommendation 7: Institutions should promote the use of the HE/FE metadata profile of ISO19115. If institutions are taking on a further advisory role, they should keep up-to- date with the specification development and interoperability programmes of the OGC. 8.Other Geospatial Standards The report has described most of the OGC implementation specifications. These specifications target a technical audience and detail the structure of the interfaces between the distributed software components. Table 2 provides a full list of OGC implementation specifications. OpenGIS Implementation Specifications Acronym Name CAT Catalog Interface CT Coordinate Transformation Services Filter Filter Encoding GML Geography Markup Language AOS GO-1 Application Objects GC Grid Coverages Common OGC Web Services Common Specification OLS Core OpenGIS Location Services: Core Services [Parts 1-5] SFC Simple Features – CORBA SFS Simple Features – SQL SFO Simple Features – OLE/COM SLD Styled Layer Descriptor WCS Web Coverage Service WFS Web Feature Service WMC Web Map Context Documents WMS Web Map Service Table 2: OpenGIS Implementation Specifications Along with the implementation specifications, readers should be aware the OGC also publishes Abstract Specifications. The Abstract Specifications (Table 3) provide the conceptual foundation for most OGC specification development activities. Open interfaces and protocols are built and referenced against the Abstract Specification, thus enabling interoperability between different brands and different kinds of spatial processing systems. Details on Abstract and Implementation Specifications can be accessed at www.opengeospatial.org. Table 3: OpenGIS Abstract Specifications Number Name Topic 0 Overview Topic 1 Feature Geometry Topic 2 Spatial Reference Systems Topic 3 Locational Geometry Topic 4 Stored Functions and Interpolation Topic 5 The OpenGIS Feature Topic 6 The Coverage Type Topic 7 Earth Imagery Topic 8 Relations between features Topic 10 Feature Collections - 26 -
  • 27. Table 3: OpenGIS Abstract Specifications Topic 11 Metadata Topic 12 The OpenGIS Service Architecture Topic 13 Catalog Services Topic 14 Semantics and Information Communities Topic 15 Image Exploitation Services Topic 16 Image Coordinate Transformation Services Table 3: OpenGIS Abstract Specifications - 27 -
  • 28. 9.Summary The report has highlighted those geospatial standards of most relevance to the JISC, it’s Information Environment and the HE/FE community as a whole and has made the following recommendations: 1 All OGC specifications are public, free of charge and non-proprietary. Wherever possible, OGC specifications should be adopted. 2 The growing trend in today’s geospatial standards development environment is towards service-oriented standards. Data users, creators, institutions and JISC services should consider this trend when considering strategies for data access and curation. However, the shift towards an SOA approach is hindered by immaturity and a lack of investment in web services infrastructure by JISC. 3 Metadata creators within the HE/FE community must conform to ISO 19115. They should create metadata compliant to the HE/FE profile of ISO 19115. However, if the HE/FE profile is not suitable, another profile of ISO 19115 should be used. 4 Users and Creators of data should be aware of: the use of GML as a data transfer format and possibly as a storage format; the growing trend towards the provision of data via web services; the continual wealth of geospatial data available in common de facto standards (de facto standards are not recommended for long term data curation).. 5 Users and creators of data should be aware of the existence of the European Petroleum Survey Group parameters for coordinate reference systems and refer to ISO 19111 Spatial Referencing by Coordinates for guidance. 6 The trend towards service-oriented geospatial standards holds great potential for other JISC services to leverage GI. Geospatial standards align well with generic Information Community interoperable standards development and therefore JISC should encourage the take up of geospatial services by other JISC services as a precedent for their shared services programme. 7 Institutions should promote the use of the HE/FE metadata profile of ISO19115. If institutions are taking on a further advisory role, they should keep up-to-date with the work of the specification development and interoperability programmes of the OGC. The roadmap below summarises the take up of those standards to date. Today Few in production environments – on Future verge of rapid growth • NTF • Regional Profiles of ISO 19115 • Gazetteers • Defacto including US, European, Australian • Geoparsers formats • Catalogs • Geocoders • HE/FE profile • Data provided as GML (e.g. OS • Geolinking ISO 19115 MasterMap) • Various other • WMS • WFS geoprocessin g services To conclude, it is recommended:  The JISC should encourage the capture of geospatial metadata compliant with the HE/FE profile of ISO 19115.  The JISC should require geospatial service provides e.g. EDINA and MIMAS to provide WMS and where appropriate WFS and WCS. - 28 -
  • 29.  The JISC should commit to the long term vision of a vibrant higher and further education SDI as described by Higgins et al (2003). Initially this can be achieved through ongoing support of its various geo-initiatives e.g. Go-Geo! Portal and geoXwalk in addition to (2).  A watching brief should be kept on the progression of geospatial standards related to geoprocessing services as these continue to evolve and concomitantly their relevance to activities within the UK academic Information Community increases. - 29 -
  • 30. Appendix A - Partitioning the GI Standards Landscape The Reference Model for Open Distributed Processing (RM-ODP, ISO/IEC 10746), [34], is an international standard for architecting open, distributed processing systems. It provides an overall conceptual framework for building distributed systems and has been used in several IT areas. In the realm of GI standards, the RM-ODP provides the conceptual basis for the ISO 19100 series of standards and the OGC Reference Model (ORM), [35]. The ORM uses the RM ODP to provide: 1. A way of thinking about architectural issues in terms of fundamental patterns or organizing principles. 2. A set of guiding concepts and terminology. Ideas discussed extensively in the ORM are presented in Table 1 in the context of their use to organise the standards in this document. Table 1. Viewpoints and levels of abstraction (adapted from the GIRM, [36]) Level of abstraction Computation Viewpoint Information Viewpoint (Service Invocation) (Information Transfer) Implementation specifications Interface Encoding (“how”) Abstract Models (“what”) Behaviour Content Standards exist at different levels of abstraction: 1. Implementation Specifications tell software engineers how to express information or requests within a specific distributed computing environment, eg, WWW, CORBA, .NET. 2. Abstract Models specify what information or requests are valid in principle, irrespective of individual computing environment. Two viewpoints are relevant to standards in this document. 1. The Computation Viewpoint is concerned with the functional decomposition of a system into a set of services that may be invoked (hence service invocation). Implementation specifications capture the interaction of these services at interfaces. Abstract models specify what the behaviour should be without reference to specific computing environments. 2. The Information Viewpoint is concerned with the semantics of information and information processing. At the abstract level, this corresponds to the content and, at the implementation level, the actual encoding of Geographic Information. This document uses the same method as the GIRM and employs geospatial topic to provide the principal organisational structure. Any standard can be considered as belonging to one of the following 5 categories: 1. Metadata and Catalogue Access 2. Data or Data Access 3. Maps and Visualisation 4. Spatial Reference Systems 5. Geoprocessing Services - 30 -
  • 31. Metadata and Catalogue Access Service invocation Information transfer Implementation OGC Catalog v2.0 ISO 19139 (Draft. Geographic specifications ISO 23950 (ANSI Z39.50), Information – Metadata – GEO and CIP profiles Implementation Specification) Abstract models ISO 19115 (Metadata) Data and Data Access – Feature Data Service invocation Information transfer Implementation OGC Simple Features access OGC Geography Markup Language specifications for OLE/COM, SQL (ISO (draft) (GML), v3.0 19125-2) OGC Web Feature Service Abstract models ISO 19125-1 (Access to Simple ISO 19107 (Spatial Schema) Features: Common ISO 19109 (Rules for Application Architecture) Schema) ISO 19110 (Methodology for Feature Cataloguing) Coverage Data Service invocation Information transfer Implementation OGC Web Coverage Service GeoTIFF specifications OGC Grid Coverage Abstract models ISO 19123 (Schema for Coverage Geometry and Functions) Maps and Visualisation Service invocation Information transfer Implementation OGC (ISO 19128) Web Map GeoTIFF, SVG, PNG, JPEG specifications Service OGC Styled Layer Descriptor OGC Web Map Context Abstract models Spatial Reference Systems Service invocation Information transfer Implementation OGC Well-Known Text (in CT, specifications SFO and SFS specs) EPSG database & CRS IDs ISO 6709:1983 Standard representation of latitude, longitude and altitude for geographic point locations ISO 19112:2003 Spatial - 31 -
  • 32. referencing by geographic identifiers Abstract models OGC Topic 2 - Spatial Referencing by Coordinates ISO 19111:2003 Spatial referencing by coordinates Geoprocessing Services Service invocation Information transfer Implementation OGC Coordinate specifications Transformation Abstract models OGC’s Topic 12 – The OpenGIS Service Architecture ISO 19119:2005 Services ISO 19112:2003 Spatial referencing by geographic identifiers ISO 19111:2003 Spatial referencing by coordinates OGC’s Topic 2 - Spatial Reference Systems - 32 -
  • 33. Appendix B - Other Relevant Standards Organisations European Committee for Standardisation (CEN) CEN [37] as an organisation and a system exists for the creation of European standards. As such, it is based in Brussels and consists of representatives from the European member states. Technical Committee (TC) 287 has responsibility for the development of Geographic Information standards. TC 287 was inactive for a period, but has now been revived (2003), principally in response to the Infrastructure for Spatial Information in Europe (INSPIRE) initiative. CEN works closely with ISO with the objective of: • Harmonising ISO and CEN standards. • Developing European profiles of ISO standards. • Avoiding duplication of work. British Standards Institution (BSI) BSI [38] is the National Standards Body of the UK, responsible for facilitating, drafting, publishing and marketing a wide variety of British Standards and other guidelines. External committee IST/36 [39] has responsibility for GI and is funded by the Association for Geographic Information (AGI). The committee reviews and evaluates standards developed by national, European and International Standards bodies, in particular ISO/TC 211, and advises on their suitability for adoption in the UK. De facto standards As epitomised by ESRI – easily the largest GI software vendor in the world. Many of ESRIs products and proprietary formats have become de facto standards. The figure below demonstrates the hierarchical nature of relevant geospatial standards’ bodies. International Standards (ISO, OGC) European Standards (CEN) National Standards (BSI) De facto Standards (ESRI) Figure 1: Standardisation Pyramid - 33 -
  • 34. Appendix C - Information Environments JISC Information Environment The most important context for this report is the JISC Information Environment. An Information Environment (IE) can be characterised as “the set of network or online services that support publishing and use of information and learning resources”. The JISC IE (as described in the five year strategy) is designed to be “an on-line information environment providing secure and convenient access to a comprehensive collection of scholarly and educational material". It is underpinned by a technical architecture specifying the set of standards and protocols to be used in developing and delivering networked services to allow users to discover, access, use and publish resources as part of their learning and research activities. The GI standards identified in this document have to be considered within the context of the JISC IE and references are made in the text to the relationship with the JISC IE where appropriate. Attention has also been paid to a related initiative taking place under the JISC Framework Programme. The Common Information Environment brings together representatives from the archives, health, research, learning and teaching communities with the aim of “Developing and evaluating a framework to facilitate interoperability across learning, teaching, research and their supporting systems”. Global Spatial Data Infrastructure (GSDI) The GSDI [40] was initially created in 1996 as a loose gathering of individuals and organisations dedicated to promoting global spatial data and making it accessible through the internet. Formally, the GSDI Association was not officially constituted until July 2003 in Cambridge, UK. It is a non-profit organisation with members from more than 50 countries with a vision of “supporting societal needs for access to and use of spatial data”. Specifically, the GSDI provides a coordinating role for those working at the global or regional scale, and provides guidance to ensure that activities at the national level are compatible within the wider framework, eg, through the publication of the SDI Cookbook. Global Mapping [41] is a closely related initiative. This international collaboration is participated in by some one hundred national mapping organizations across the world with the aim of developing digital cartographic data of the whole landmass of the Earth with consistent specifications and available to anyone at marginal cost. The International Steering Committee for Global Mapping (ISCGM) is working together with GSDI to realise Global SDI development by developing Global Map. European Spatial Data Infrastructure INSPIRE (Infrastructure for Spatial Information in Europe) is an initiative launched by the European Commission during 2002. It aims to make available relevant, harmonised and quality GI to support formulation, implementation, monitoring and evaluation of Community policies. INSPIRE is an initiative that will lead to an official EU Directive addressing technical standards and protocols, organisational and co-ordination issues, data policy issues including data access and the creation and maintenance of GI. It is the first step of a broad multi-sectoral initiative and will provide the legislative basis for the European Spatial Data Infrastructure. The initial focus is on the GI needed for environmental policies with the aim being to ensure better and more accessible information on the environment for citizens. UK National SDI The Association for Geographic Information (AGI), is the professional organisation representing the interests of the various sectors of the GI industry in the UK. The AGI and the Ordnance Survey (OS) are two of the most significant organisations in terms of furthering UK SDI developments. As yet, there is no formal UK wide NSDI, although key components are in place. For example: - 34 -
  • 35. • The GIGateway service [42], provides access to a wide variety of UK geospatial metadata to aid GI discovery. GIgateway is funded through the Office of the Deputy Prime Minister’s National Interest Mapping Services Agreement (NIMSA). It is run by the AGI and hosted by EDINA under contract. • GI Strategies have been drawn up (or are in the process of being drafted) by the constituent member countries of the UK, i.e. England, Scotland, Wales and Northern Ireland. The AGI has taken the lead on this. • The OS has developed the concept of the Digital National Framework (DNF) [43], “a model for the integration of geographic information of all kinds – from national reference datasets to application information at the local level”. OS has already engineered its topographic framework of the country on the foundation of DNF and released the first layers of its related OS MasterMap suite of products. Digital National Framework As developed by the Ordnance Survey, the DNF “a model for the integration of geographic information of all kinds – from national reference datasets to application information at the local level”. Not formally a standard, it is recommended that DNF be considered as best-practice guidelines that will evolve over time. The intention is to provide the means for organisations that hold and manage core SDI datasets, eg, OS, DEFRA, Scottish Executive, etc, to work together to establish better linkages and promote interoperabilty. As a consequence, it is recognised that the success of the DNF will be heavily dependent upon the uptake and use of many of the standards discussed in this document, eg, those developed by the OGC. The OS has a history of active engagement with the OGC and was one of the first National Mapping Agencies to seriously use GML, eg, MasterMap topographic layer (based on DNF principles) was released in 2001. Every feature within MasterMap is assigned a unique topographic identifier (TOID) thereby enabling multiple possibilities in terms of data linkage and interoperability. The OS is promoting the idea that datasets which are integrated using this reference base, ie, where TOIDs representing constituent features in a dataset features are aggregated and stored against the users own business identifiers, are eligible to be registered with the DNF registry. The latter is not established yet but is proposed as a repository for “DNF enabled” dataset metadata, related ancillary information and services. e-Government Interoperability Framework (e-GIF) The e-GIF defines the minimum set of technical policies and specifications governing information flows across UK government and the public sector [44]. The main objectives are to align to with the global information revolution in order improve government effectiveness and maximise the economic benefits of government information resources. Adherence to e-GIF is mandatory for government and public sector organisations. The criteria used to select specifications for adoption in the Technical Standards Catalogue include: • Interoperability – only specifications that are relevant to systems’ interconnectivity, data integration, e-services access and content management metadata are specified. • Openness – the specifications are documented and available to the public. • International standards – preference is given to the standards with the broadest remit. As yet, the JISC has no official position on e-GIF, however, the draft report on Developing Guidance on Technical Standards for JISC Development Activity and Service Interoperability states: • The JISC, in selecting standards, should align with the e-GIF. • The JISC standards adoption framework should mirror that of the e-GIF. • Where e-GIF makes no recommendation in a standards area, the JISC may make recommendations for itself but should take into consideration possible future e-GIF decisions. - 35 -
  • 36. However, it is clearly recognised in the Duke and Jordan report that it is important for JISC to retain the freedom to conduct leading edge, innovative projects and not be unduly constrained by e-GIF. - 36 -
  • 37. Appendix D - References 1.World Summit on the Information Society, December 2003, http://www.itu.int/wsis/docs/geneva/ official/dop.html 2.Nebert, D. (ed) 2001 Developing Spatial Data Infrastructures: The SDI Cookbook. GSDI Cookbook, Version 1.1 3.HEIPORT http://ads.ahds.ac.uk/cfm/heirport2/si.cfm 4.Spatial Data Infrastructures and Digital Libraries, Reid, J. et al (2004) http://www.dlib.org/dlib/may04/reid/05reid.html 5.ISO/TC 211 Geographic Information/Geomatics http://www.isotc211.org/ 6.Open Geospatial Consortium http://www.opengeospatial.org/ 7.GeoXWalk………… ……. http://www.jisc.ac.uk/index.cfm?name=project_xwalk3 8.Conformance Interoperability Testing Engine http://cite.occamlab.com/ 9.OGC Registered Products ……..http://www.opengeospatial.org/resources/?page=products 10.Medyckyj-Scott D, Newman I, Ruggles C and Walker D (eds), 1989, Metadata in the Geosciences, Group D Publications, Loughborough. 11.Review of Metadata Standards, O’Hanlon, 2001… http://edina.ac.uk/projects/geobrowser/ 12.Go-Geo http://www.gogeo.ac.uk 13.Association for Geographic Information http://www.agi.org.uk 14.Cabinet Office e-Government Unit http://www.cabinetoffice.gov.uk/e-government 15.UK Data Archive at the University of Essex http://www.data-archive.ac.uk/ 16.Federal Geographic Data Committee http://www.fgdc.gov 17.e-GIF v6.1 Technical Standards Catalogue http://www.govtalk.gov.uk/egif/contents.asp 18.Ordnance Survey http://www.ordnancesurvey.co.uk/oswebsite/ 19.Spatial Data Transfer Standard http://mcmcweb.er.usgs.gov/sdts/ 20.Digital Geographic Information Exchange Standard http://www.digest.org/ 21.Environmental Systems Research Institute http://www.esri.com 22.AutoCAD http://www.autodesk.com 23.MapInfo http://www.mapinfo.com 24.National Land and Property Gazetteer http://www.nlpg.org.uk/ 25.International Hydrographic Office http://www.iho.shom.fr/ 26.GeoTIFF http://www.remotesensing.org/geotiff/geotiff.html 27.JISC Information Environment http://www.jisc.ac.uk/ie 28.JISC Information Environment Architecture http://www.ukoln.ac.uk/distributed-systems/jisc-ie/ arch/standards/ 29.Interoperability Stack, Atkinson, R. http://www.anzlic.org.au/pubinfo/2389440524 30.JISC Information Environment Service Registry http://iesr.ac.uk/ 31.GSDI Cookbook, Version 2.0 http://www.gsdi.org/gsdicookbookindex.asp 32.The Grid 2: Blueprint for a New Computing Infrastructure, 2003, Ian Foster and Carl Kesselman (eds). 33.Geo-Data Portal – Development Programme – Phase 4a, Boyle et al, 2005 http://www.gogeo.ac.uk/Go-Geo_Phase_4a_Final_Report_NO_COSTS.doc 34.Open Distributed Processing – Reference Model, ISO/IEC 10746-1, 1st Edition,1998, http://www.iso.ch/iso/en/ittf/PubliclyAvailableStandards/c020696_ISO_IEC_10746-1_1998(E).zip - 37 -
  • 38. 35.OpenGIS Reference Model,Version:0.1.2shttp://www.opengeospatial.org/specs/?page=orm 36.Geospatial Interoperability Reference Model (GIRM), John Evans, v1.1, Dec 2003 http://gai.fgdc.gov/girm/v1.1/ 37.European Committee for Standardization http://www.cenorm.be/cenorm/index.htm 38.British Standards Institution http://www.bsi-global.com/index.xalter 39.BSI Committee for Geographic Information http://www.gistandards.org.uk/ 40.Global Spatial Data Infrastructure Association http://www.gsdi.org/ 41.International Steering Committee for Global Mapping http://www.iscgm.org/html4/index.html 42.GIgateway http://www.gigateway.org.uk/ 43.The Digital National Framework – evolving a framework for interoperability across all kinds of information. A White Paper by Ordnance Survey, September 2004. http://www.ordnancesurvey.co.uk/aboutus/reports/dnf_qa.pdf 44.e-Government Interoperability Framework. Version 6.0 30 April 2004 http://www.govtalk.gov.uk/schemasstandards/egif.asp - 38 -