BS-EN-ISO-19123-2007.pdf

BRITISH STANDARD BS EN ISO 19123:2007 Incorporating amendment no. 1 (renumbers BS ISO 19123:2005 as BS EN ISO 19123:2007) Geographic information Schema for coverage geometry and functions The European Standard EN ISO 19123:2007 has the status of a British Standard ICS 35.240.70 ? Licensed Copy: London South Bank University, London South Bank University, Wed May 16 03:42:59 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS EN ISO 19123:2007 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 26 October 2005 © BSI 2007 ISBN 0 580 46706 6 National foreword This British Standard was published by BSI. It is the UK implementation of EN ISO 19123:2007. It is identical with ISO 19123:2005. The UK participation in its preparation was entrusted to Technical Committee IST/36, Geographic information. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publication Amd. No. DateComments 1710831 May 2007Renumbers BS ISO 19123:2005 as BS EN ISO 19123:2007 Licensed Copy: London South Bank University, London South Bank University, Wed May 16 03:42:59 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN ISO 19123 March 2007 ICS 35.240.70 English Version Geographic information - Schema for coverage geometry and functions (ISO 19123:2005) Information géographique - Schéma de la géométrie et des fonctions de couverture (ISO 19123:2005) Geoinformation - Coverage Geometrie- und Funktionsschema (ISO 19123:2005) This European Standard was approved by CEN on 25 February 2007. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels © 2007 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 19123:2007: E Licensed Copy: London South Bank University, London South Bank University, Wed May 16 03:42:59 GMT+00:00 2007, Uncontrolled Copy, (c) BSI Foreword The text of ISO 19123:2005 has been prepared by Technical Committee ISO/TC 211 “Geographic information/Geomatics” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 19123:2007 by Technical Committee CEN/TC 287 “Geographic Information“, the secretariat of which is held by NEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2007, and conflicting national standards shall be withdrawn at the latest by September 2007. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 19123:2005 has been approved by CEN as EN ISO 19123:2007 without any modifications. EN ISO 19123:2007 Licensed Copy: London South Bank University, London South Bank University, Wed May 16 03:42:59 GMT+00:00 2007, Uncontrolled Copy, (c) BSI Reference number ISO 19123:2005(E) INTERNATIONAL STANDARD ISO 19123 First edition 2005-08-15 Geographic information Schema for coverage geometry and functions Information géographique Schéma de la géométrie et des fonctions de couverture EN ISO 19123:2007 Licensed Copy: London South Bank University, London South Bank University, Wed May 16 03:42:59 GMT+00:00 2007, Uncontrolled Copy, (c) BSI ii Licensed Copy: London South Bank University, London South Bank University, Wed May 16 03:42:59 GMT+00:00 2007, Uncontrolled Copy, (c) BSI iii Contents Page Foreword. v Introduction . vi 1 Scope . 1 2 Conformance. 1 3 Normative references . 2 4 Terms, definitions, abbreviated terms and notation . 2 4.1 Terms and definitions. 2 4.2 Abbreviated terms 7 4.3 Notation . 7 5 Fundamental characteristics of coverages 8 5.1 The context for coverages . 8 5.2 The coverage schema 9 5.3 CV_Coverage. 10 5.4 CV_DomainObject. 13 5.5 CV_AttributeValues 13 5.6 CV_CommonPointRule. 14 5.7 CV_DiscreteCoverage 14 5.8 CV_GeometryValuePair 15 5.9 CV_ContinuousCoverage 16 5.10 CV_ValueObject 17 5.11 CV_InterpolationMethod 18 5.12 Subclasses of CV_ContinuousCoverage . 18 6 Discrete coverages . 18 6.1 Discrete coverage types 18 6.2 CV_DiscretePointCoverage . 19 6.3 CV_PointValuePair 20 6.4 CV_DiscreteGridPointCoverage 20 6.5 CV_GridPointValuePair 21 6.6 CV_DiscreteCurveCoverage 21 6.7 CV_CurveValuePair 22 6.8 CV_DiscreteSurfaceCoverage . 22 6.9 CV_SurfaceValuePair . 24 6.10 CV_DiscreteSolidCoverage . 24 6.11 CV_SolidValuePair 24 7 Thiessen polygon coverage 25 7.1 Thiessen polygon networks 25 7.2 CV_ThiessenPolygonCoverage. 25 7.3 CV_ThiessenValuePolygon . 27 8 Quadrilateral grid coverages . 27 8.1 General. 27 8.2 Quadrilateral grid geometry. 27 8.3 CV_Grid 30 8.4 CV_GridEnvelope 31 8.5 CV_GridPoint. 31 8.6 CV_GridCoordinate. 32 8.7 CV_GridCell . 32 8.8 CV_Footprint . 33 8.9 CV_RectifiedGrid 33 EN ISO 19123:2007 Licensed Copy: London South Bank University, London South Bank University, Wed May 16 03:42:59 GMT+00:00 2007, Uncontrolled Copy, (c) BSI iv 8.10 CV_ReferenceableGrid . 34 8.11 CV_ContinousQuadrilateralGridCoverage . 35 8.12 CV_GridValueCell 36 8.13 CV_GridPointValuePair 36 8.14 CV_GridValuesMatrix 37 8.15 CV_SequenceRule 38 8.16 CV_SequenceType 38 9 Hexagonal Grid Coverages 39 9.1 General . 39 9.2 CV_HexagonalGridCoverage . 39 9.3 CV_GridValuesMatrix 41 9.4 CV_ValueHexagon 41 10 Triangulated irregular network (TIN) coverages 41 10.1 General . 41 10.2 CV_TINCoverage . 43 10.3 CV_ValueTriangle 43 11 Segmented curve coverages . 44 11.1 General . 44 11.2 CV_SegmentedCurveCoverage . 45 11.3 CV_ValueCurve . 45 11.4 CV_ValueSegment 46 11.5 Evaluation 46 Annex A (normative) Abstract test suite 47 Annex B (informative) UML Notation 51 Annex C (informative) Interpolation methods 56 Annex D (informative) Sequential enumeration. 60 Bibliography . 65 EN ISO 19123:2007 Licensed Copy: London South Bank University, London South Bank University, Wed May 16 03:42:59 GMT+00:00 2007, Uncontrolled Copy, (c) BSI v Foreword ISO (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 technical 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 electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention 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 rights. ISO 19123 was prepared by Technical Committee ISO/TC 211, Geographic information/Geomatics. EN ISO 19123:2007 Licensed Copy: London South Bank University, London South Bank University, Wed May 16 03:42:59 GMT+00:00 2007, Uncontrolled Copy, (c) BSI vi Introduction Geographic phenomena fall into two broad categories discrete and continuous. Discrete phenomena are recognizable objects that have relatively well-defined boundaries or spatial extent. Examples include buildings, streams and measurement stations. Continuous phenomena vary over space and have no specific extent. Examples include temperature, soil composition and elevation. A value or description of a continuous phenomenon is only meaningful at a particular position in space (and possibly time). Temperature, for example, takes on specific values only at defined locations, whether measured or interpolated from other locations. These concepts are not mutually exclusive. In fact, many components of the landscape may be viewed alternatively as discrete or continuous. For example, a stream is a discrete entity, but its flow rate and water quality index vary from one position to another. Similarly, a highway can be thought of as a feature or as a collection of observations measuring accidents or traffic flow, and an agricultural field is both a spatial object and a set of measurements of crop yield through time. Historically, geographic information has been treated in terms of two fundamental types called vector data and raster data. “Vector data” deals with discrete phenomena, each of which is conceived of as a feature. The spatial characteristics of a discrete real-world phenomenon are represented by a set of one or more geometric primitives (points, curves, surfaces or solids). Other characteristics of the phenomenon are recorded as feature attributes. Usually, a single feature is associated with a single set of attribute values. ISO 19107:2003 provides a schema for describing features in terms of geometric and topological primitives. “Raster data”, on the other hand, deals with real-world phenomena that vary continuously over space. It contains a set of values, each associated with one of the elements in a regular array of points or cells. It is usually associated with a method for interpolating values at spatial positions between the points or within the cells. Since this data structure is not the only one that can be used to represent phenomena that vary continuously over space, this International Standard uses the term “coverage,” adopted from the Abstract Specification of the Open GIS Consortium 1, to refer to any data representation that assigns values directly to spatial position. A coverage is a function from a spatial, temporal or spatiotemporal domain to an attribute range. A coverage associates a position within its domain to a record of values of defined data types. In this International Standard, coverage is a subtype of feature. A coverage is a feature that has multiple values for each attribute type, where each direct position within the geometric representation of the feature has a single value for each attribute type. Just as the concepts of discrete and continuous phenomena are not mutually exclusive, their representations as discrete features or coverages are not mutually exclusive. The same phenomenon may be represented as either a discrete feature or a coverage. A city may be viewed as a discrete feature that returns a single value for each attribute, such as its name, area and total population. The city feature may also be represented as a coverage that returns values such as population density, land value or air quality index for each position in the city. A coverage, moreover, can be derived from a collection of discrete features with common attributes, the values of the coverage at each position being the values of the attributes of the feature located at that position. Conversely, a collection of discrete features can be derived from a coverage, each discrete feature being composed of a set of positions associated with specified attribute values. EN ISO 19123:2007 Licensed Copy: London South Bank University, London South Bank University, Wed May 16 03:42:59 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 1 Geographic information Schema for coverage geometry and functions 1 Scope This International Standard defines a conceptual schema for the spatial characteristics of coverages. Coverages support mapping from a spatial, temporal or spatiotemporal domain to feature attribute values where feature attribute types are common to all geographic positions within the domain. A coverage domain consists of a collection of direct positions in a coordinate space that may be defined in terms of up to three spatial dimensions as well as a temporal dimension. Examples of coverages include rasters, triangulated irregular networks, point coverages and polygon coverages. Coverages are the prevailing data structures in a number of application areas, such as remote sensing, meteorology and mapping of bathymetry, elevation, soil and vegetation. This International Standard defines the relationship between the domain of a coverage and an associated attribute range. The characteristics of the spatial domain are defined whereas the characteristics of the attribute range are not part of this standard. 2 Conformance This International Standard specifies interfaces for several types of coverage objects. In addition, it supports the interchange of coverage data independently of those interfaces. Thus, it specifies two sets of conformance classes: one for implementation of the interfaces, the other for the exchange of coverage data. Each set includes one conformance class for each type of coverage specified in this International Standard (Table 1). Table 1 Conformance classes Conformance class Subclause Simple coverage interface A.1.1 Discrete coverage interface A.1.2 Thiessen polygon coverage interface A.1.3 Quadrilateral grid coverage interface A.1.4 Hexagonal grid coverage interface A.1.5