1、BSI Standards PublicationBS ISO 19136-2:2015Geographic information Geography Markup Language(GML)Part 2: Extended schemas and encodingrulesBS ISO 19136-2:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 19136-2:2015.The UK participation in its preparation w
2、as entrusted to TechnicalCommittee IST/36, Geographic information.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication.
3、 The British Standards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 79891 7ICS 35.240.70Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 3
4、1 August 2015.Amendments issued since publicationDate Text affectedBS ISO 19136-2:2015 ISO 2015Geographic information Geography Markup Language (GML) Part 2: Extended schemas and encoding rulesInformation gographique Langage de balisage en gographie (GML) Partie 2: Schmas tendus et rgles dencodageIN
5、TERNATIONAL STANDARDISO19136-2First edition2015-08-01Reference numberISO 19136-2:2015(E)BS ISO 19136-2:2015ISO 19136-2:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may
6、 be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the
7、requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 19136-2:2015ISO 19136-2:2015(E)Foreword viIntroduction vii1 Scope . 12 Conformance . 13 Normative references 24 Terms, definitions, s
8、ymbols and abbreviated terms . 24.1 General . 24.2 Terms and definitions . 24.3 Symbols and abbreviated terms. 35 Conventions . 35.1 MIME media types . 35.2 XML namespaces . 35.3 Deprecated parts of previous versions of GML . 46 Additional base types 56.1 Target namespace . 56.2 Localisable strings
9、. 56.2.1 LanguageStringType . 56.2.2 Additional types based on LanguageStringType 56.3 TimePositionUnion . 56.4 Requirements class . 76.5 Conformance . 77 Compact Encodings of Commonly Used GML Geometries 87.1 Target namespace . 87.2 Introduction 87.3 SimplePolygon . 87.4 SimpleRectangle 97.5 Simple
10、Triangle . 107.6 SimpleArcString 107.7 SimpleArc 117.8 SimpleArcByCenterPoint . 117.9 SimpleArcStringByBulge . 127.10 SimpleArcByBulge . 127.11 SimpleCircle 137.12 SimpleCircleByCenterPoint . 137.13 SimpleMultiPoint . 147.14 MultiPointPropertyType 147.15 Requirements class 147.16 Conformance 148 Tri
11、angulated Irregular Networks.158.1 Target namespace 158.2 Introduction . 158.3 TriangulatedSurface 158.4 SimpleTrianglePatch . 158.5 TIN 168.6 TINElement . 168.7 TINElementPropertyType 178.8 TINElementTypeType 178.9 Requirements class 198.10 Conformance 209 Linear Referencing 209.1 Target namespaces
12、 . 20 ISO 2015 All rights reserved iiiContents PageBS ISO 19136-2:2015ISO 19136-2:2015(E)9.2 Introduction . 209.3 Basic Linear Referencing . 219.3.1 Target namespace 219.3.2 Introduction 219.3.3 PositionExpression .219.3.4 PositionExpressionPropertyType 219.3.5 LinearElement .229.3.6 LinearElementPr
13、opertyType . 239.3.7 StartValueType .239.3.8 LinearReferencingMethod 239.3.9 LinearReferencingMethodPropertyType .249.3.10 DistanceExpressionType . 249.3.11 DistanceExpressionPropertyType .259.3.12 AlongReferent 259.3.13 AlongReferentPropertyType 259.3.14 Referent 269.3.15 ReferentPropertyType .279.
14、3.16 MeasureType 279.3.17 LRMNameType .279.3.18 LRMTypeType . 319.3.19 ReferentTypeType .329.3.20 LinearSRS 339.3.21 LinearSRSPropertyType . 339.4 Linear Referencing Towards Referent . 349.4.1 Target namespace 349.4.2 Introduction 349.4.3 DualAlongReferent 349.4.4 DualAlongReferentPropertyType .349.
15、5 Linear Referencing Offset . 359.5.1 Target namespace 359.5.2 Introduction 359.5.3 LRMWithOffset .359.5.4 LRMWithOffsetPropertyType 359.5.5 LateralOffsetDistanceExpressionType .369.5.6 LateralOffsetExpressionType . 369.5.7 VerticalOffsetExpressionType . 379.5.8 LateralOffsetDirectionType . 389.5.9
16、VerticalOffsetDirectionType 399.5.10 LateralOffsetLinearSRS .399.5.11 LateralOffsetLinearSRSPropertyType 409.6 Linear Referencing Offset Vectors . 419.6.1 Target namespace 419.6.2 Introduction 419.6.3 VectorOffsetDistanceExpressionType 419.6.4 VectorOffsetExpressionType 419.6.5 VectorOffsetLinearSRS
17、 .429.6.6 VectorOffsetLinearSRSPropertyType 459.7 Requirements classes . 459.8 Conformance 4710 ReferenceableGrid .4810.1 Target namespace 4810.2 Clarifications to ISO 19123:2005 . 4810.3 AbstractReferenceableGrid . 4910.4 ReferenceableGridByArray 5010.5 ReferenceableGridByVectorsType, Referenceable
18、GridByVectors5110.6 ReferenceableGridByTransformation 5710.7 gridCRS . 5810.8 Coverages using ReferenceableGrid 58iv ISO 2015 All rights reservedBS ISO 19136-2:2015ISO 19136-2:2015(E)10.9 Requirements classes . 5810.10 Conformance 5911 Code lists, dictionaries and definitions6011.1 Overview . 6011.2
19、 Requirements class 6111.3 Conformance 6212 Encoding rule 6212.1 Target namespace 6212.2 Improved conversion rule 6212.2.1 Conversion rule changes 6212.2.2 Requirements class .6412.2.3 Conformance 6512.3 Association class conversion rule 6712.3.1 Overview 6712.3.2 Requirements class .6812.3.3 Confor
20、mance 6912.4 Encoding rule extensions 7012.4.1 Overview 7012.4.2 gmlexr:extendedEncodingRule 7012.4.3 Requirements class .7012.4.4 Conformance class .71Annex A (informative) Linear referencing method examples .73Bibliography .78 ISO 2015 All rights reserved vBS ISO 19136-2:2015ISO 19136-2:2015(E)For
21、ewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a techn
22、ical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
23、electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document w
24、as drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directivesAttention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent ri
25、ghts. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received. www.iso.org/patentsAny trade name used in this document is information given for the convenience of users and does not constitute a
26、n endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.The Geography
27、 Markup Language (GML) was originally developed within the Open Geospatial Consortium (OGC). The Committee responsible for this document is ISO/TC 211, Geographic information/Geomatics.ISO 19136 consists of the following parts, under the general title Geographic Information Geography Markup Language
28、: Part 2: Extended schemas and encoding rulesA future Part 1 will revise and replace the currently available ISO 19136:2007.vi ISO 2015 All rights reservedBS ISO 19136-2:2015ISO 19136-2:2015(E)IntroductionGeography Markup Language is an XML grammar written in XML Schema for the description of applic
29、ation schemas as well as the transport and storage of geographic information.The key concepts used by Geography Markup Language (GML) to model the world are drawn from the ISO 19100- series of International Standards and the OpenGIS Abstract Specification.A feature is an “abstraction of real world p
30、henomena” (ISO 19101); it is a geographic feature if it is associated with a location relative to the Earth. So a digital representation of the real world may be thought of as a set of features. The state of a feature is defined by a set of properties, where each property may be thought of as a name
31、, type, value triple.The number of properties a feature may have, together with their names and types, is determined by its type definition. Geographic features with geometry are those with properties that may be geometry-valued. A feature collection is a collection of features that may itself be re
32、garded as a feature; as a consequence a feature collection has a feature type and thus may have distinct properties of its own, in addition to the features it contains.Following ISO 19109, the feature types of an application or application domain is usually captured in an application schema. A GML a
33、pplication schema is specified in XML Schema and can be constructed in two different and alternative ways: by adhering to the rules specified in ISO 19109 for application schemas in UML, and conforming to both the constraints on such schemas and the rules for mapping them to GML application schemas
34、specified in this part of ISO 19136; by adhering to the rules for GML application schemas specified in this part of ISO 19136 for creating a GML application schema directly in XML Schema.Both ways are supported by this part of ISO 19136. To ensure proper use of the conceptual modelling framework of
35、the ISO 19100- series of International Standards, all application schemas are expected to be modelled in accordance with the General Feature Model as specified in ISO 19109. Within the ISO 19100- series, UML is the preferred language by which to model conceptual schemas.GML specifies XML encodings,
36、conformant with ISO 19118, of several of the conceptual classes defined in the ISO 19100- series of International Standards and the OpenGIS Abstract Specification. These conceptual models include those defined in: ISO/TS 19103, Geographic information Conceptual schema language (units of measure, bas
37、ic types); ISO 19107, Geographic information Spatial schema (geometry and topology objects); ISO 19108, Geographic information Temporal schema (temporal geometry and topology objects, temporal reference systems); ISO 19109, Geographic information Rules for application schemas (features); ISO 19111,
38、Geographic information Spatial referencing by coordinates (coordinate reference systems); ISO 19123, Geographic information Schema for coverage geometry and functions; ISO 19148, Geographic information Linear referencing.The aim is to provide a standardized encoding (i.e. a standardized implementati
39、on in XML) of types specified in the conceptual models specified by the International Standards listed above. If every application schema were encoded independently and the encoding process included the types from, for example, ISO 19108, then, without unambiguous and completely fixed encoding rules
40、, the XML encodings would be different. Also, since every implementation platform has specific strengths and weaknesses, it is helpful to standardize XML encodings for core geographic information concepts modelled in the ISO 19100- series of International Standards and commonly used in application s
41、chemas. ISO 2015 All rights reserved viiBS ISO 19136-2:2015ISO 19136-2:2015(E)In many cases, the mapping from the conceptual classes is straightforward, while in some cases the mapping is more complex (a detailed description of the mapping is part of this part of ISO 19136).In addition, GML provides
42、 XML encodings for additional concepts not yet modelled in the ISO 19100- series of International Standards or the OpenGIS Abstract Specification, for example, dynamic features, simple observations or value objects.Predefined types of geographic feature in GML include coverages and simple observatio
43、ns.A coverage is a subtype of feature that has a coverage function with a spatiotemporal domain and a value set range of homogeneous 1- to n-dimensional tuples. A coverage may represent one feature or a collection of features “to model and make visible spatial relationships between, and the spatial
44、distribution of, Earth phenomena” (OGC Abstract Specification Topic 6) and a coverage “acts as a function to return values from its range for any direct position within its spatiotemporal domain” (ISO 19123).An observation models the act of observing, often with a camera or some other procedure, a p
45、erson or some form of instrument (Merriam-Webster Dictionary: “an act of recognizing and noting a fact or occurrence often involving measurement with instruments”). An observation is considered to be a GML feature with a time at which the observation took place, and with a value for the observation.
46、A reference system provides a scale of measurement for assigning values to a position, time or other descriptive quantity or quality.A coordinate reference system consists of a set of coordinate system axes that is related to the Earth through a datum that defines the size and shape of the Earth.A t
47、emporal reference system provides standard units for measuring time and describing temporal length or duration.A reference system dictionary provides definitions of reference systems used in spatial or temporal geometries.Spatial geometries are the values of spatial feature properties. They indicate
48、 the coordinate reference system in which their measurements have been made. The “parent” geometry element of a geometric complex or geometric aggregate makes this indication for its constituent geometries.Temporal geometries are the values of temporal feature properties. Like their spatial counterp
49、arts, temporal geometries indicate the temporal reference system in which their measurements have been made.Spatial or temporal topologies are used to express the different topological relationships between features.A units-of-measure dictionary provides definitions of numerical measures of physical quantities, such as length, temperature and pressure, and of conversions between units.viii ISO 2015 All rights reservedBS ISO 19136-2:2015INTERNATIONAL STANDARD ISO 19136-2:2015(E)Geographic information Geography Markup La
