Standards

These pages of the wiki are based on Part C: Standards for fundamental geo-spatial datasets of the Guidelines of Best Practice for the Acquisition, Storage, Maintenance and Dissemination of Fundamental Geo‐Spatial Datasets.

The Standards page (this page) provides background information on geospatial standardization: a standard and different types of standards are defined; the development and implementation of standards are described; and key standards bodies for fundamental geospatial datasets are introduced. Standards relevant for the acquisition and maintenance of fundamental geospatial datasets are listed with links to implementation benefits and guidelines of individual standards used in the collection, maintenance and dissemination of geospatial data.

The wiki was created by the ICA Commission on SDI and Standards and is maintained by the Commission, ISO/TC 211, Geographic information/Geomatics and other volunteers.

Background

Types of standards

A standard is a document (or a collection of documents), usually but not always published, that specifies requirements, recommendations, conventions and/or guidelines used consistently to ensure that a product, service, system or any other standardization target is fit for its purpose. Standards can be developed and implemented in different ways, and describe different things at different levels of abstraction and/or detail. The following table provides an overview of standard deliverables for different purposes. A profile is a set of one or more base standards or subsets of base standards, and, where applicable, the identification of chosen clauses, classes, options and parameters of those base standards, that are necessary for accomplishing a particular function ISO 19106:2004. In the geospatial community, profiles for international standards are sometimes developed for national and regional application. For example, SANS 1878-1: 2005, South African spatial metadata standard, Part 1: Core metadata profile, is a profile of ISO 19115:2003, Geographic information – Metadata, developed by the SABS for use in South Africa.

ISO/IEC deliverables (Source: ISO/IEC Directives, Part 1 and Consolidated ISO Supplement, 2016 (7th edition))

Deliverable	Description
International Workshop Agreement (IWA)	An IWA aims to bridge the gap between the activities of consortia and the formal process of standardization represented by ISO and its national members. An important distinction is that the IWA is developed by ISO workshops and fora, comprising only participants with direct interest, and is therefore not accorded the status of an International Standard.
International Standard (IS)	An International Standard is a standard that is adopted by an ISO or IEC and made available to the public.
Publicly Available Specification (PAS)	A Publicly Available Specification is developed to respond to an urgent market need, representing either a consensus in an organisation external to ISO or IEC; or a consensus of the experts within a working group. A PAS is not allowed to conflict with an existing International Standard, but competing Publicly Available Specifications on the same subject are permitted.
Technical Report (TR)	A Technical Report contains collected data of a different kind from that normally published as an International Standard or Technical Specification. This may include, for example, data obtained from a survey carried out among the national bodies, data for example, data obtained from a survey carried out among the national bodies, data on work in other international organisations or data on the “state of the art” in relation to standards of national bodies on a particular subject.
Technical Specification (TS)	A Technical Specification is developed when there is the future possibility of agreement on an International Standard, but for which at present the required support for approval as an International Standard cannot be obtained; there is doubt on whether consensus has been achieved; the subject matter is still under technical development; or there is another reason precluding immediate publication as an International Standard.

A standard is concerned with one or more standardization targets (i.e. the object of standardization), for example, a data model, a web service, a system, or a process. The following tables list different levels of abstraction at which standardization targets are described and describe different types of heterogeneity, which geo-spatial standards aim to overcome. A geo-spatial standard may standardize geographic data, services, or procedures at more than one level of abstraction and address more than one type of heterogeneity. However, often a single level and a single type of heterogeneity are prominent in the standard.

Different levels of abstraction and detail in standards (Source: ISO 19101-1:2014)

Deliverable	Description
Meta-meta	Meta-meta standards cover the more general aspects of geo-spatial information and serve as foundations for other standards. Examples are ISO 19101:2002, Geographic information – Reference model, and ISO/TS 19103:2005, Geographic information – Conceptual schema language.
Meta	Meta standards standardize aspects of geo-spatial information that are used in other standards and applications. Examples are ISO 19107:2003, Geographic information – Spatial schema, and ISO 19110:2005, Geographic information -- Methodology for feature cataloguing.
Application	Application standards are directly implementable. Examples are ISO 19136:2007, Geographic information – Geography markup language (GML), and OGC KML Version 2.2.0.
Instance	Instance standards are concerned with the standardization of data and services or applications processing data. Examples are the different geospatial data formats.

Four types of heterogeneity (Source: ISO 19101-1:2014)

Type of heterogeneity	Description
System	System heterogeneity exists at the ‘lowest’ level between hardware, operating systems and communication systems. Standards to overcome this type of heterogeneity are typically developed by organisations focusing on general-purpose information and communication technology, such as the ISO/IEC JTC 1, IETF, and W3C.
Syntactic	Syntactic heterogeneity concerns the physical representation of data, i.e. the symbols and the grammar used to convey data within a message from a sender to a receiver. Syntactic heterogeneity is concerned with the appearance of the message but not in its content. Examples are different geo-spatial data formats, such as DXF and SHP.
Structural	Structural heterogeneity (also called schematic heterogeneity) is concerned with the differences related to conceptual modelling of geographic features. For example, a street name can be represented either by a single attribute (e.g. ‘Church Street’) or by two attributes, one for the name (e.g. ‘Church’) and the other for the type (e.g. ‘Street’).
Semantic	Semantic heterogeneity refers to the differences in meaning between concepts and data used to represent geographic features. For example, two individuals may perceive a bridge in different ways leading to different concepts: a road infrastructure, an obstacle for marine navigation, a point of interest, etc.

Development of standards

Conventionally, standards are developed by international or national standards organisations, such as the International Organization for Standardization (ISO), and the South African Bureau of Standards (SABS). However, industry consortia are playing an increasingly important role in standards development, both nationally and internationally. Typically, an industry consortium in standards development is a membership organisation formed to ensure performance and quality in a particular industry or economic sector. Examples in the IT industry are the Internet Engineering Task Force (IETF) and World Wide Web Consortium (W3C) and the Open Geospatial Consortium (OGC) in the geo-spatial industry. Industry consortia are seldom accredited by national or international standards organisations, but their standards usually have strong support within a relatively short span of time because they are developed by members of the industries concerned, by consensus of stakeholders and by using an open review and approval process.

A variety of definitions for open standards exist, emphasizing different aspects of openness.

Generally, in the geospatial community open standards refer to standards developed according to the principles of open standards formulated by Bruce Perens. These include the ability of stakeholders to participate voluntarily in standards development, the use of consensus in the review and standards approval process, providing public access to all development documents, maximizing end-user choice by prohibiting vendor lock-in and ultimately providing access to the completed standards to allow royalty-free implementations and extensions. Legally, the developer of an open standard retains all related patents and intellectual property rights but third party users are free to support and create products that conform to it. Geo-spatial standards developed by the ISO, OGC and the International Hydrographic Organization (IHO), as well as IETF and W3C, are generally considered to be open.

Proprietary standards are developed by organisations for their products or services. Developers of proprietary standards have sole ownership and retain all patents associated with the standards, even though they might publish them. Third party users are sometimes allowed to use a proprietary standard, either by paying a prescribed licence fee or free of charge, but they do not play any part in its development and maintenance. In the geo-spatial domain, the Autodesk DXF (Drawing Exchange Format) and Esri shape (SHP) files are examples of proprietary data format standards that have been published.

Public domain standards are not owned or developed and maintained by a particular organisation, but developed collectively by a user community. GeoTIFF is an example of a public domain standard.

Implementation of standards

Standard implementation is either mandatory (de jure) through government legislation andregulations, or voluntary (de facto) through consensus and popular acceptance by the community.Sometimes standards developed by official standards bodies are also referred to as being de jure.

The scope usually appears at the beginning of a standard and defines without ambiguity the subject of the document and the aspects covered, thereby indicating the limits of applicability of the document or particular parts of it.

A standard contains informative and normative elements. Informative elements identify the document, introduce its content and explain its background, development and relationship with other documents; or provide additional information intended to assist the understanding or use of the document. Normative elements describe the scope of the document or set out provisions. Provisions are expressed as

• requirements, i.e. expressions conveying criteria to be fulfilled if compliance with the document is to be claimed and from which no deviation is permitted);
• recommendations, i.e. expressions conveying that among several possibilities one is recommended as particularly suitable, without mentioning or excluding others, or that a certain course of action is preferred but not necessarily required, or that (in the negative form) a certain possibility or course of action is deprecated but not prohibited;
• permission, i.e. a course of action permissible within the limits of the document; or
• statements of possibility or capability.

Typical verbal forms for requirements are ‘shall’ and ‘shall not’, while ‘should’ and ‘should not’ are used for recommendations. For example, ‘data quality shall be described using the [specified] data quality elements’ (ISO 19157:2013) and ‘a data quality evaluation method should be included for each applied data quality measure’ (ISO 19157:2013). Verbal forms for the expression of provisions are described in Annex H of ISO/IEC Directives Part 2 (2011).

Key standards bodies for geospatial data

The three international standardization organisations that produce most of the geo-spatial standards relevant to the acquisition, maintenance and dissemination of fundamental geo-spatial datasets are introduced in this section.

International Organization for Standardization (ISO)

ISO is the world’s largest developer of voluntary International Standards. International Standards provide state of the art specifications for products, services and good practice, helping to make industry more efficient and effective. Developed through global consensus, they help to break down barriers to international trade. ISO was founded in 1947 and since then has published more than 19,000 International Standards covering almost all aspects of technology and business, from food safety to computers, and agriculture to healthcare, impacting on people’s daily lives. ISO aims to be as inclusive as possible when it comes to its membership.

Three member categories, each with a different level of access and influence over the ISO system, allow countries with limited resources or without a fully developed national standards system to still observe and keep up to date with international standardization in ISO. Full members (or member bodies) influence ISO standards development and strategy by participating and voting in ISO technical and policy meetings. Full members sell and adopt ISO International Standards nationally.Correspondent members observe the development of ISO standards and strategy by attending ISO technical and policy meetings as observers. Correspondent members can adopt ISO International Standards nationally.Subscriber members keep up to date on ISO’s work but cannot participate in it.They do not adopt ISO International Standards nationally.

Members have to clearly indicate their intended participation in each of the technical committees. There are two options. P-members participate actively in the work, with an obligation to vote on all questions formally submitted for voting within the technical committee, on new work item proposals, enquiry drafts and final draft International Standards and contribute to meetings. O-members follow the work as an observer and therefore receive committee documents and have the right to submit comments and to attend meetings.

Most African countries participate in ISO as full or corresponding members. These member bodies are typically the national standards organisations, such as the SABS in South Africa and Instituto Angolano de Normalização e Qualidade (IANORQ) in Angola. Three quarters of the 161 ISO members are from developing countries.

ISO technical work is carried out under the overall management of the Technical Management Board (TMB). The TMB reports to the ISO Council and its role is defined in the statutes of the organisation. TMB tasks include setting up technical committees, appointing chairs and monitoring the progress of technical work. ISO/IEC Directives Part 1 Consolidated ISO Supplement (2014) provide official procedures to be followed when developing and maintaining an International Standard and procedures specific to ISO. ISO/IEC Directives Part 2 (2011) details the principles to structure and draft documents intended to become International Standards, Technical Specifications or Publicly Available Specifications. ISO standards are developed by groups of experts within technical committees (TC). ISO/TCs are made up of representatives of industry, NGOs, governments,academia and other stakeholders, who are put forward by ISO’s members. Each TC deals with a different subject.

Information about ISO is available at http://www.iso.org . Standards that are adopted by national member bodies are also available on their websites (sometimes cheaper than on the ISO website). See for example, http://www.sabs.co.za.

Cooperation with other standards organisations
The Vienna agreement (1991) ensures technical cooperation with the European Committee for Standardization (CEN). CEN Technical Committee for geographic information, CEN/TC 287, is the mirror committee to ISO/TC 211. It adopts their standards in order to make them mandatory within the European Union and produces technical guidance and best practice for spatial data infrastructures.

ISO/IEC JTC 1[1]is a joint Technical Committee in which ISO and the International Electrotechnical Commission (IEC) collaborate on standardization in the field of information technology. Some of the standards developed in ISO/IEC JTC 1 are referenced in standards for geospatial information, for example, standards defining the Unified Modeling Language (UML) and the Structured Query Language (SQL).

Technical committees may establish liaison relationships with international or broadly based regional organisations working or interested in similar or related fields. Two categories of liaison are possible at the technical committee level. Category A liaison organisations make an effective contribution to the work of the technical committee, have access to all relevant documentation and are invited to meetings. They may nominate experts to participate in working groups preparing drafts of standards. Category B organisations indicate a wish to be kept informed of the work of the technical committee or subcommittee and have access to reports on the work of a technical committee.

Development of standards
Once the need for a standard has been established, experts meet face-to-face or through online mechanisms to discuss and negotiate the draft standard. The draft is shared with ISO’s members and liaisons who are asked to comment and vote on it. If consensus is reached, the draft becomes an ISO standard, if not, it goes back to the technical committee for further edits.

An ISO International Standard embodies the essential principles of global openness and transparency, consensus and technical coherence safeguarded through its development in a technical committee, representative of all interested parties and supported by a public comment phase (the ISO Technical Enquiry). Other ISO deliverables (ISO/TS, ISO/PAS, ISO/TR, see below) require lower levels of consensus and therefore do not have the same status as an International Standard. Consensus is defined as general agreement, characterised by the absence of sustained opposition to substantial issues by any important part of the concerned interests and by a process that involves seeking to take into account the views of all parties concerned and to reconcile any conflicting arguments. Note that consensus does not imply unanimous approval.

ISO standards are developed following a project approach. The project stages, associated documents and a brief description of each stage are provided in the table below. National member bodies may participate in or follow this project approach through representation in the relevant technical committees. ISO documents are reviewed systematically at three or five year intervals, depending on the type of document. Depending on the voting results of systematic reviews, a document is confirmed (retention without technical change), amended or revised (retention, with change/s), or withdrawn.

ISO project stages

Project stage	Associated document	Brief description
Preliminary stage	Preliminary work item (PWI)	This stage is used for work that is not yet sufficiently mature for processing to further stages and for which no target dates can be established. For example, the stage can be used for the elaboration of a new work item proposal and the development of an initial draft.
Proposal stage	New work item proposal(NWIP)	The committee votes on the approval of a NWIP, which has to be within its scope. Ideally, a first working draft should be attached to the NWIP. A project leader is nominated in the NWIP. The NWIP is approved by simple majority of the committees P-members and if a specified minimum number of technical experts are nominated for the project.
Preparatory stage	Working draft(s) (WD)	During this stage a number of WDs are prepared. The stage ends when the WD is available for circulation to the members of the committee. The project leader is responsible for the development of the project and will normally convene and chair any meetings.
Committee stage	Committee draft(s) (CD)	This is the principal stage during which comments from national bodies are taken into consideration, with a view to reaching consensus on the technical content. An editing committee is convened, which shall supply responses to all comments. The stage ends when there is consensus that the document is ready for circulation in the next stage.
Enquiry stage	Enquiry draft (DIS)	During this stage the DIS is circulated to all national member bodies. The DIS is approved if a two-thirds majority of the votes cast by P-members are in favour, and not more than one-quarter of the total number of votes cast are negative. A DIS with no negative votes proceeds directly to publication.
Approval stage	Final draft international standard (FDIS)	The FDIS is again circulated to all national member bodies.The FDIS is approved if a two-thirds majority of the votes cast by the P-members are in favour, and not more than onequarter of the total number of votes cast are negative.
Publication stage	International Standard	The document is published by the ISO Central Secretariat.

Standards development, from approval of a proposed project to final publication stage, takes between 24 to 48 months. Standard development can be fast-tracked under certain circumstances,e.g. the proposal, preparatory and committee stages are skipped and the standard is submitted for vote as an enquiry draft. Fast tracking is applied, for example, if an existing standard from another standardization organisation is submitted to ISO for publication as a standard. The technical committee leadership may advise that the approval stage is omitted if DIS voting results and comments suggest that no additional work in an FDIS stage is required. A resolution to confirm the intention to skip the FDIS stage is published.

Table below lists the informative and normative elements of an ISO document. Mandatory elements are indicated in bold; upright type elements are normative and italic type elements are informative.

ISO document structure

Type of element	Element	Description
Preliminary informative	Title page	Title of the document, e.g. ‘ISO 19157, Geographic information – Data quality’
	Table of contents	Mandatory if it makes the document easier to consult.
	Foreword	Information about the organisation (e.g. the technical committee) responsible for the document and a summary of significant changes from a previous version, if applicable.
	Introduction	Background information about the document and reasons prompting its preparation.
General normative	Title
	Scope	The scope defines without ambiguity the subject of the document and the aspects covered, thereby indicating the limits of applicability of the document or particular parts of it. It shall not contain any requirements.
	Normative references	A list of the referenced documents cited in the document in such a way as to make them indispensable for the application of the document.
Technical normative	Terms and definitions	A list of terms and definitions necessary for the understanding of certain terms used in the document.
	Symbols and abbreviations	A list of the symbols and abbreviated terms necessary for the understanding of the document.
	Requirements	All characteristics relevant to the aspects of the standardization target covered by the document, either explicitly or by reference. For each requirement, either a reference to the test method for determining or verifying the values of the characteristic, or the test method itself shall be provided.
	Normative annex	Provisions additional to those in the body of the document.
Supplementary informative	Informative annex
Technical normative	Normative annex	Provisions additional to those in the body of the document.
Supplementary informative	Bibliography	A list of referenced documents and information resources.
	Indexes	An index for the standard.

ISO/TC 211, Geographic information/Geomatics
ISO/TC 211 is the ISO technical committee responsible for standardization of geographic information. Its work aims at establishing a structured set of standards for information concerning objects or phenomena that are directly or indirectly associated with a location relative to the Earth. More specifically, it covers semantic, syntactic and service issues, as well as procedural standards, at various levels of abstraction. At the time of writing (17 October 2014), ISO/TC 211 had 35 participating members, 31 observing members and liaison relationships with more than 30 international organisations and more than 15 other ISO/TCs. African members are South Africa and Botswana who are a P-members; Kenya, Mauritius, Morocco, United Republic of Tanzania and Zimbabwe who are Omembers; and Swaziland who is a corresponding member. ISO/IEC Directive Part 1 Consolidated ISO Supplement (2014) provides guidelines for twinning agreements, where developing country member bodies may establish P-member twinning arrangements with P-members from developed countries.

The development of a standard in ISO/TC 211 is assigned to one of six thematic working groups (WG): WG 1, Framework and reference model; WG 4, Geospatial services; WG 6, Imagery; WG 7, Information communities; WG 9, Information management; and WG 10, Ubiquitous public access. A number of maintenance groups ensure harmonization among the ISO/TC 211 standards: the Program Maintenance Group (PMG), the Terminology Maintenance Group (TMG), the Harmonized Model Maintenance Group (HMMG), the XML Maintenance Group (XMG) and the Group on Ontology Management (GOM). A control body for the ISO geodetic registry network is workingtowards an international registry of geodetic codes and parameters.

The TMG maintains a multi-lingual glossary of terms and definitions as they appear in ISO/TC 211 standards. At the time of writing (17 October 2014), the glossary was available on the ISO/TC 211 website and had been translated, in whole or in part, into Arabic, Chinese, Danish, Dutch, English, Finnish, French, German, Japanese, Korean, Polish, Russian, Spanish and Swedish. The HMMG maintains a harmonised model of the UML models and diagrams in all standards. This model is available for download, online access or online viewing on the ISO/TC 211 website.

Open Geospatial Consortium (OGC)

OGC is an industry consortium that defines, documents and tests implementation standards for geo-spatial content and services. OGC standards leverage the abstract standards defined by ISO/TC 211. OGC work is driven by member organisation requirements, staff analysis of market trends and OGC Board of Directors guidance. In all cases, the mission is the integration of geo-spatial content and services into applications for the benefit of humankind.

OGC membership is open to any organisation or individual. Four types of membership (associate, technical, principal and strategic) provide increasing levels of influence on standardsdevelopment. Reduced membership fees apply to lower income countries.OGC currently has 480+ members representing governments, the private sector, universities, NGOs, research communities and the open source community. OGC work is guided by member approved Policies and Procedures, that evolve in response to member and market requirements.

OGC standards are technical documents that detail interfaces or encodings. Software developers use these documents to build open interfaces and encodings into their products and services. Ideally, if OGC standards are implemented in products or online services by two or more different software engineers working independently, the resulting components can be used together (i.e. plug-and-play) without further debugging.

Development of standards
OGC standards work occurs primarily in two major activities: the Interoperability Program and the Standards Program. The Interoperability Program provides a facilitated, rapid engineering (agile) lifecycle approach to capturing interoperability requirements and then using those requirements and use cases to prototype applications (software) that either test existing OGCstandards against those requirements, often providing change requests to existing standards; or develop new candidate standards or extensions to existing standards. The work of an interoperability initiative then feeds directly into the standards program.

Candidate standards are submitted by three or more member organisations. Candidate standards may have been developed outside OGC (such as KML), developed by a Standards Working Groups (SWG), or submitted as a result of an interoperability initiative. The Standards Program has Domain Working Groups (DWG) and SWGs. DWGs are open to any member, as well as the public (non-members). DWGs are open fora for discussion of requirements, use cases and issues, and for members to present implementations of OGC standards and lessons learned. SWGs are for members and invited guests. Standards documents are prepared and maintained by SWGs. The OGC Policies and Procedures and the OGC Intellectual Property policies guide the work in the SWGs.

All OGC standards, when approved, are freely and publicly available on a royalty free, nondiscriminatory basis (RAND-RF) at http://www.opengeospatial.org. Any schemas (xsd, xslt, etc.) that support a published OGC standard can be found in the official OGC Schema Repository on the OGC website.

Compliance testing
In the OGC Compliance Program implementations of OGC standards are tested and certified if they comply with relevant standards. Vendors can certify their products to be compliant with OGC standards. This ensures that their products can be integrated with other products and services. Compliance testing is free, but an annual trademark licensing fee is due for using the “Certified OGC Compliant” Mark associated with an OGC Standard. Compliance testing is guided by the Compliance Testing Program Policies & Procedures. A list of compliant products is available on the OGC website.

International Hydrographic Organization (IHO)

IHO is an intergovernmental consultative and technical organisation established in 1921 to support safety of navigation and the protection of the marine environment. Among its main objectives, IHO is to bring about the greatest possible uniformity (i.e. standardization) in nautical charts and documents. The establishment and maintenance of hydrographical standards rest with the IHO Programme ‘Hydrographic Services and Standards’, under the responsibility of the IHO Hydrographic Services and Standards Committee (HSSC). The provision of hydrographical and nautical chart services is one of the obligations of coastal State signatories to the International Convention for the Safety of Life at Sea (SOLAS) under the responsibility of the International Maritime Organization (IMO). The SOLAS Convention (IMO 2009) stipulates that ‘Contracting Governments undertake to ensure the greatest possible uniformity in charts and nautical publications and to take into account, whenever possible, the appropriate resolutions and recommendations adopted by the International Hydrographic Organization’.

The current IHO membership is composed of 81 coastal states. The official representatives of member governments within IHO are normally the national Hydrographer, or Director of Hydrography, who, together with their technical staff, meet in Monaco at the International Hydrographic Conference (IHC). IHC holds ordinary sessions at five-year intervals and extraordinary sessions in the interim period as required. All IHO decisions are made by the member states during IHC sessions or by postal voting between IHC sessions. Each member state has one vote in ordinary decision-making.

Development of standards
The principles and procedures for developing IHO standards are laid out in a resolution, initially approved by IHO Member States in 2007. This resolution applies to “standards” and “guides” as defined by ISO. The development, consultation and approval process ranges from a very comprehensive regime for new publications and significant changes to existing publications (new editions or revisions), requiring formal approval by a majority of the Member States, to approval at the level of a subordinate body (committee, sub-committee, working group) for simple clarifications.

Proposals to develop a new publication, a new edition or a revision are considered by the relevant IHO Committee, generally the HSSC, but not exclusively. When assessing the proposal, the Committee concerned considers the impact on relevant stakeholders, including a risk and feasibility analysis and an estimate of the resources needed for the development and the implementation of the new or revised standard. After the Committee has endorsed proposals and established a work priority, the relevant tasks are incorporated in the IHO work programme. Relevant stakeholders are notified of the timetable for new work items and invited to comment and participate as appropriate. At the successful completion of the development and testing phases for new standards and proposed changes to existing standards, the Committee reviews the work done in terms of its impact on relevant stakeholders and whether the appropriate non-IHOstakeholder consultation process has been achieved. After endorsement by the Committee, the new or changed standard is submitted to the approval of member states (simple majority).

The IHO Secretariat maintains an on-line register of IHO stakeholders used to inform and seek input from stakeholders. Stakeholders include other international organisations, maritime administrations, equipment manufacturers, data distributors, users and professional organisations.

Cooperation between IHO, ISO/TC 211 and OGC

The guidelines in this and the following chapter include standards from IHO, ISO/TC 211 and OGC. It is important to note that some of these standards are joint publications, cross-reference each other or depend on each other. Therefore this section provides a brief overview of the cooperation between the three standardization organisations.

OGC and IHO are category A liaisons of ISO/TC 211. Category A liaisons are organisations that make an effective contribution to the work of the technical committee for questions dealt with by the technical committee. Such organisations are given access to all relevant documentation and are invited to meetings. They may nominate experts to participate on the development of standards in working groups.

OGC and ISO/TC 211 have a long history of collaboration and development of joint standards documents. Selected OGC standards are submitted to [http://www.isotc211.org ISO/TC 211 for consideration for approval as International Standards. OGC develops standards that can be directly implemented. Many of these implementation standards are based on the conceptual (or abstract) models defined by ISO or jointly by OGC and ISO.

The cooperation between IHO and ISO/TC 211 has been driven by the development of standards for digital hydrographical information and products. IHO recognised the benefits of developing standards based on some or all of the parts of the ISO 19100 series or other related standards and both organisations agreed to formalise their cooperation through a Memorandum of Understanding in order to strengthen the joint development of international standards and to avoid duplication of work on standards related to hydrography and nautical charting and related data,products and services.

IHO members, IHO technical staff and IHO nominated experts attend ISO/TC 211 working groups and plenary meetings and participate in the work in a non-voting capacity. IHO’s Category A liaison with ISO/TC 211 provides overall co-ordination of this activity within IHO. Conversely, ISO/TC 211 representatives participate as non-voting liaison members in IHO committees and working groups so that reciprocal liaison is achieved.

Other standards developing organisations

Geo-spatial standards refer to and depend on standards developed in other organisations. A brief introduction to the three most important organisations is provided below.

The Geomatics Committee of the International Association of Oil and Gas Producers (OGP), previously known as the Surveying & Positioning Committee, was formed in 2005 by the absorption into OGP of the now-defunct European Petroleum Survey Group (EPSG). The OGP Geomatics Committee, through its Geodesy Subcommittee, maintains and publishes a dataset of parameters for coordinate reference system and coordinate transformation description. The EPSG Geodetic Parameter Dataset is referenced in various data formats, including the GeoTIFF interchange format for geo-referenced raster imagery (see GeoTIFF Format Specification). EPSG codes are used to uniquely identify a coordinate reference system in various IHO, OGC and ISO standards for geo-spatial data, for example, ISO 19128:2005, Geographic information – Web Map Server interface, and OpenGIS Web Map Server Implementation Specification.

The Internet Engineering Task Force (IETF) develops and promotes standards for the Internet. Its mission is to make the Internet work better by producing relevant technical documents that influence the way people design, use and manage the Internet. The IETF is an open standard organisation with no formal membership, membership requirements or fees. Some of the IETF standards are referenced in standards for geo-spatial information, especially where geo-spatial information is made available over the Internet, for example, IETF RFC 3986, Uniform Resource Identifier (URI): Generic Syntax.

The World Wide Web Consortium (W3C) develops technical specifications and guidelines for web applications. W3C members are organisations or individuals. Membership fees vary depending on the annual revenues, type and location of headquarters of an organisation. Some of the W3C standards are referenced in geo-spatial information standards, for example, W3C XML, Extensible Markup Language (XML) 1.0 (Second Edition), W3C Recommendation (6 October 2000).

Two regional African standardization organisations are worth mentioning. The SADC Cooperation in Standardization (SADCSTAN) is the sole body mandated by the Council of Ministers of countries in the Southern African Development Community (SADC) to promote the coordination of standardization activities and services in the region, with the purpose of achieving harmonization of standards and technical regulations (with the exception of the legal metrology regulations) in support of the objectives of the SADC Trade Protocol. The protocol aims to facilitate trade, economic liberalization and development for deeper regional integration and poverty eradication as well as the establishment of the SADC common market. To date, a technical committee on geo-spatial information has not been established.

The African Regional Organisation for Standardization (ARSO) aims to facilitate global trade through harmonised standards and conformity systems and procedures. Paid subscription membership is open to all African countries through their national standards bodies or departments dealing with standards and quality. Thirteen Technical Harmonisation Committees deal with standards ranging from Agriculture and Food Products to Electro-technology and Traditional Medicine. Currently,there is no Technical Harmonisation Committees dealing with standards on geo-spatial information specifically.

Infrastructure standards

This set of standards was developed to provide an infrastructure for the further standardization of geographic information:

• ISO 19101-1:2014, Geographic information -- Reference model, describes the standardization environment within which the standardization of geographic information is expected to take place.

• The OGC Abstract Specification references many ISO standards and provides a reference model for the development of OGC Implementation Standards.

• OGC Reference Model describes the OGC Standards Baseline, i.e. the approved OGC Abstract and Implementation Standards and OGC Best Practice documents (informative documents).

• ISO 19104, Geographic information -- Terminology, lays out a methodology for defining the terms needed in the area of geographic information.

• ISO 19103:2015, Geographic information -- Conceptual schema language, identifies the conceptual schema language selected for characterization of geographic information and describes how that language is to be used.

• ISO 19105:2000, Geographic information -- Conformance and testing, specifies general principles for describing how geographic information products and services are expected to conform to the standards developed by ISO/TC 211.

• ISO 19106:2004, Geographic information -- Profiles, specifies how profiles of the ISO/TC 211 standards are to be structured.

Geospatial data formats

These standards describe encodings for geographic information:

• Esri Shapefile (SHP)

• GeoTIFF Format Specification

• GMLJP2 (OGC GML in JPEG2000)

• HDF-5

• S-57 IHO, Transfer standard for digital hydrographic data

• ISO 19136:2007, Geographic information -- Geography Markup Language (GML)

• ISO 19162:2015, Geographic information -- Well known text representation of coordinate reference systems

• ISO/IEC 15444-1:2004, Information technology -- JPEG 2000 image coding system: Core coding system

• ISO/IEC8211:1994, Information technology -- Specification for a data descriptive file for information interchange

• OGC GeoPackage Encoding Standard

• OGC KML

• OGC Network Common Data Form (netCDF)

• Well known binary (WKB)

Data model standards

This set of standards builds on the ISO/TC 211 reference model. The data model standards provide a family of abstract conceptual schemas for describing the fundamental components of features as elements of geographic information.

For generic geospatial data

• ISO 19107:2003, Geographic information -- Spatial schema, specifies UML classes for representing the spatial characteristics of features as composites of geometric and/or topological primitives.

• ISO 19108:2002, Geographic information -- Temporal schema, does the same as ISO 19107 for the temporal characteristics of features and also specifies classes for describing relevant temporal reference systems.

• ISO 19109:2015, Geographic information -- Rules for application schema, specifies a general feature model for integrating these components into features and provides rules for doing so in an application schema.

• ISO 19137:2007, Geographic information -- Core profile of the spatial schema, provides a profile of ISO 19107 that is limited to describing features as simple geometric primitives of 0, 1, or 2 dimensions.

• ISO 19123:2005, Geographic information -- Schema for coverage geometry and functions, provides a schema for an alternative representation of spatial information as a coverage, in which non-spatial attributes are assigned directly to geometric objects rather than to features composed of such objects.

• ISO 19125-1:2004, Geographic information -- Simple feature access – Part 1: Common access, describes a common architecture for providing access to information about features with simple geometry.

• ISO 19125-2:2004, Geographic information -- Simple feature access – Part 2: SQL option, specifies a Structured Query Language implementation of ISO 19125-1.

• ISO/TS 19129:2009, Geographic information -- Imagery, gridded and coverage data framework

• ISO/TS 19130:2010, Geographic information -- Imagery sensor models for geopositioning

• ISO 19141:2008, Geographic information -- Schema for moving features, extends ISO 19107 to support the description of moving geometric objects.

For geospatial data in specific application domains

• ISO 19144-2:2012, Geographic information -- Classification systems – Part 2: Land cover meta language

• ISO 19152:2012, Geographic information -- Land Administration Domain Model (LADM)

• ISO 19156:2011, Geographic information -- Observations and Measurements

• ISO 19160-1:2015, Geographic information -- Addressing – Part 1: Conceptual model

• ISO 14825:2011, Intelligent transport systems – Geographic Data Files (GDF)

• IHO S-100, Universal hydrographic data model

• IHO S-44, IHO Standards for Hydrographic Surveys

Metadata standards

This set of standards, with the exception of Dublin Core, is also built on the domain reference model of ISO 19101-1, but, in contrast to the data model standards, which are focused on individual features and their characteristics, these standards are focused on the description of data sets containing information about one or, typically, many feature instances.

• ISO 15836:2009, Information and documentation -- The Dublin Core metadata element set

• ISO 19115-1:2014, Geographic information -- Metadata Fundamentals

• ISO 19115-2:2009, Geographic information -- Metadata – Part 2: Extensions for imagery and gridded data

• ISO/TS 19115-3, Geographic information -- Metadata – Part 3: XML implementation of fundamentals

• ISO/TS 19139:2007, Geographic information -- Metadata – XML schema implementation (of ISO 19115:2003 Metadata, so under revision)

• ISO/TS 19139-2:2012, Geographic information -- Metadata – XML schema implementation – Part 2: Extensions for imagery and gridded data

Geographic information management standards

This set of standards is also built on the domain reference model of ISO 19101-1, but, in contrast to the data model standards, which are focused on individual features and their characteristics, these standards are focused on the description of data sets containing information about one or, typically, many feature instances.

• ISO 19110:2005, Geographic information -- Methodology for feature cataloguing, specifies a methodology for developing catalogues containing definitions of feature types and their property types, including feature attributes, feature associations, and feature operations.

• ISO 19126:2009, Geographic information -- Feature concept dictionaries and registries

• S-11, Guidance for the preparation and maintenance of international chart schemes and catalogue of international charts

• ISO 19111:2007, Geographic information -- Spatial referencing by coordinates. Geographic information contains spatial references which relate the features represented in the data to positions in the real world. Spatial references fall into two categories: those using coordinates; and those based on geographic identifiers. ISO 19111 provides a schema for describing the coordinate reference systems used to relate the position of geometric primitives to the earth or another object.

• ISO 19112:2003, Geographic information -- Spatial referencing by geographic identifiers. Geographic information contains spatial references which relate the features represented in the data to positions in the real world. Spatial references fall into two categories: those using coordinates; and those based on geographic identifiers. ISO 19112 provides a general model for spatial referencing using geographic identifiers, as well as specifying the components of a spatial reference system and the essential components of a gazetteer.

• ISO 19127:2016 (to be published), Geographic information -- Geodetic register, applies the principles of ISO 19111 and ISO 19135-1 to establish rules for the population and maintenance of the ISO geodetic register.

• ISO 19131:2007, Geographic information -- Data product specifications, describes requirements for specifying the characteristics expected of a geographic data product.

• ISO 19135-1:2015, Geographic information -- Procedures for item registration -- Part 1: Fundmentals, specifies procedures for establishing and maintaining registers of identifiers and meanings assigned to items of geographic information.

• ISO 19157:2013, Geographic information -- Data quality, establishes a set of principles for describing and reporting the quality of geographic information.

• ISO/TS 19158:2012, Geographic infomration -- Quality assurance of data supply

• ISO 19159-1:2014, Geographic information -- Calibration and validation of remote sensing imagery sensors

• IHO S-58 draft, IHO Recommended ENC validation checks

• IHO S-99, Operational procedures for the organisation and management of S-100 geospatial information registry

Map standards

These standards are related to the presentation of geographic information on maps:

• ISO 19117:2012, Geographic information -- Portrayal, provides a schema for specifying symbols and mapping them to an application schema.

• IHO S-4, Regulations of the IHO for international (INT) charts and chart specifications of the IHO

• IHO S-52, Specifications for chart content and display aspects of ECDIS

• IHO S-65, ENCs: Production, maintenance and distribution guidance

• IHO S-66, Facts about electronic charts and carriage requirements

• OGC Styled Layer Descriptor (SLD) defines an encoding that extends the WMS standard to allow user-defined symbolization and coloring of geographic feature and coverage data. SLD addresses the need for users and software to be able to control the visual portrayal of the geospatial data served over the Web.

• OGC Symbology Encoding (SE) defines an XML language for styling information that can be applied to digital feature and coverage data.

Standards for Web dissemination

This set of standards builds on the reference model to support the dissemination of geographic information, e.g. through web services.

• ISO 19119:2005, Geographic information -- Services, extends the architecture reference model to provide a framework for specifying individual geographic information services.

• ISO 19116:2004, Geographic information -- Positioning services, specifies an interface between position-providing devices and position-using devices. ISO 19117 provides a schema for specifying symbols and mapping them to an application schema.

• ISO 19128:2005, Geographic informaation -- Web Map Server interface, also published as the OGC Web Map Service (WMS), specifies a set of interfaces for producing spatially referenced maps from geographic information available through the world wide web.

• OpenGIS Web Map Tile Service Implementation Standard specifies an interface for serving map tiles of spatially referenced data using tile images with predefined content, extent, and resolution.

• ISO 19142:2010, Geographic information -- Web Feature Service, also published as OGC Web Feature Service (WFS), specifies the behaviour of a web feature service that provides transactions on and access to geographic features in a manner independent of the underlying data store. It specifies discovery operations, query operations, locking operations, transaction operations and operations to manage stored parameterized query expressions.

• ISO 19143:2010, Geographic information -- Filter encoding, also published as OGC Filter Encoding, describes an XML and KVP encoding of a system neutral syntax for expressing projections, selection and sorting clauses, collectively called a query expression. These components are modular and intended to be used together or individually by other standards.

• OGC Catalogue Service supports the ability to publish and search collections of descriptive information (metadata) for data, services, and related information objects.

• OGC Sensor Observation Service (SOS) defines a Web service interface which allows querying observations, sensor metadata, as well as representations of observed features.

External links

• International Hydropgraphic Organization (IHO)
• ISO ISO/TC 211, Geographic information/Geomatics page on ISO website
• ISO/TC 211, Geographic information/Geomatics website
• ISO/TC 211 Harmonized Model
• ISO/TC 211 Multilingual Glossary of Terms
• ISO/TC 211 Standards Guide
• Kresse, W and Fadaie, K 2004. ISO Standards for Geographic Information, Springer, ISBN 978-3-662-08039-9
• Open Geospatial Consortium (OGC)
• United Nations Committee of Experts on Global Geospatial Information Management (UN GGIM) - Resource documents

Acknowledgments

The original Part C was commissioned by Dr Derek Clarke, Chief Director: National Geo-Spatial Information in the Department of Rural Development and Land Reform, South Africa. The authors were Serena Coetzee, Antony Cooper and Victoria Rautenbach.

The structure of this wiki is partially based on the Standards Guide ISO/TC 211 Geographic information/Geomatics (N2726).

The contribution of Sajani Joshi MSc and Tanzeel Ur Rehman Khan, alumni of the Stuttgart University of Applied Sciences, for the creation of the wiki are gratefully acknowledged.