Classification Related Features

The SEDRIS Data Representation Model APPENDIX A - Classes Classification Related Features

Class Name: Classification Related Features

Superclass - <Aggregate Feature>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class specifies an aggregation of <Feature Hierarchy> instances organized according to their ECCs such that each <Feature Hierarchy> component represents:

a different thematic layer, or
a different classification of <Feature Representation> instances within a single thematic layer.

Each branch of a <Classification Related Features> instance therefore has a <Classification Data> instance associated with it as a link object, specifying its (possibly elaborated) classification.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

This class appears on only one page of the DRM class diagram.

Example

Several thematic layers of features might be grouped using a <Classification Related Features> instance, with each of its components representing a separate thematic layer (such as culture or vegetation). In such a case, the unique_descendants and strict_organizing_principle flags of the <Classification Related Features> instance should be set to SE_TRUE. The <Classification Data> link object associated with each of its components identifies the contents of each thematic layer, and each of the components is an independent topological complex and has a <Feature Topology Hierarchy> component.
A region consisting of forest and water is represented as a <Classification Related Features> instance with strict_organizing_principle set to SE_TRUE, containing two <Union Of Features> components. The first <Union Of Features> component, containing the forest features, is specified through a <Classification Data> link object with tag = ECC_FOREST, while the second <Union Of Features> component, containing the water features, is specified through a <Classification Data> link object with tag = ECC_WATER.
Considering the first example, suppose that roads run through the forest. The forest <Union Of Features> instance can then be replaced with another <Classification Related Features> instance having two branches, one representing environmental objects classified as ECC_ROAD and the other environmental objects classified as ECC_FOREST, and the strict_organizing_principle flag in the <Classification Related Features> instance from the previous example is set to SE_FALSE, because the forest branch at the coarse level contains non-forest (in this case, road) features.
A large collection of features might be organized using a <Classification Related Features> instance with multiple <Union Of Features> components, containing cultural, vegetation, and surface drainage features, respectively.

FAQs

What is the purpose of this class?: The <Classification Related Features> class exists to provide a mechanism for hierarchically organizing <Feature Representation> instances according to their (possibly elaborated) classification.

Constraints

Associated to (one-way) (inherited)

zero or more <Feature Representation> instances, each through the use of a <Base Association Data> link object¹
zero or more <Geometry Hierarchy> instances, each through the use of a <Base Association Data> link object²
zero or more <Property Grid> instances, each through the use of a <Base Association Data> link object³

Associated by (one-way) (inherited)

zero or more <Feature Representation> instances, each through the use of a <Base Association Data> link object⁴
zero or more <Geometry Hierarchy> instances, each through the use of a <Base Association Data> link object⁵
zero or more <Property Grid> instances, each through the use of a <Base Association Data> link object⁶
zero or one <Hierarchy Summary Item> instance

Composed of (two-way) (inherited)

zero or one <Classification Data> instance
zero or more <Label> instances
zero or more {ordered} <Property Set Index> instances
zero or more <Property Table> instances
zero or more <Property Table Reference> instances
zero or more <Property Value> instances
zero or one <Rendering Priority Level> instance
zero or one <Reference Surface> instance
zero or more <Sound Instance> instances
zero or more <Base LOD Data> instances
zero or more <Colour> instances
zero or more <Feature Topology Hierarchy> instances
zero or more {ordered} <Image Mapping Function> instances⁷
zero or one <Perimeter Data> instance
zero or one <Presentation Domain> instance⁸
zero or more <Property Description> instances
zero or one <Spatial Extent> instance

Composed of (two-way)

one or more <Feature Hierarchy> instances, each through the use of a <Classification Data> link object

Composed of (two-way metadata) (inherited)

zero or one <Data Quality> instance
zero or one <Identification> instance
zero or one <Time Constraints Data> instance

Component of (two-way) (inherited)

zero or more <Union Of Features> instances
zero or more <Alternate Hierarchy Related Features> instances, each through the use of a <Hierarchy Data> link object
zero or more <Classification Related Features> instances, each through the use of a <Classification Data> link object
zero or one <Environment Root> instance
zero or one <Feature Model> instance
zero or more <LOD Related Features> instances, each through the use of a <Base LOD Data> link object
zero or more <Octant Related Features> instances, each through the use of a <Octant Data> link object
zero or more <Perimeter Related Features> instances, each through the use of a <Perimeter Data> link object
zero or more <Quadrant Related Features> instances, each through the use of a <Quadrant Data> link object
zero or more <Spatial Index Related Features> instances, each through the use of a <Spatial Index Data> link object
zero or more <State Related Features> instances, each through the use of a <State Data> link object
zero or more <Time Related Features> instances, each through the use of a <Time Constraints Data> link object

Inherited Field Elements

SE_Boolean	unique_descendants;	⁹
SE_Boolean	strict_organizing_principle;	¹⁰

Notes

Associated to Notes

An association between two <Feature Representation> instances indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.

Geometry_Hierarchy

An association between a <Geometry Hierarchy> instance and a <Feature Representation> instance indicates that the environmental object(s) that they represent have the semantic relationship indicated by the <Base Association Data> link object on the association relationship.

Property_Grid

An association between a <Property Grid> instance and a <Feature Representation> instance indicates that the environmental object(s) represented by the <Feature Representation> instance and the <Property Grid> instance (or some specific cell data within that <Property Grid> instance) have the semantic relationship indicated by the <Base Association Data> link object on the association relationship. Each associated <Property Grid> instance indicates whether the entire <Property Grid> instance or only some specific cell data within it is participating in the relationship in question.

Associated from Notes

Feature_Representation

Geometry_Hierarchy

Property_Grid

Composed of Notes

Image_Mapping_Function

The <Image Mapping Function> components support texture mapping information for geometry that is to be derived from the <Aggregate Feature> instance by the consumer. These <Image Mapping Function> instances shall use <Image Anchor> components to specify the mapping.

Presentation_Domain

A <Presentation Domain> component is needed for <Aggregate Feature> instances that are significant only for a particular domain, such as radar.

Fields Notes

unique_descendants

If the value of the unique_descendants field is SE_TRUE, each descendant shall be unique in the sense that it shall appear in only one branch of this aggregation. Each descendant is a <Feature Representation> instance within the component tree rooted at the <Aggregate Feature> instance. If unique_descendants is SE_FALSE, at least one <Feature Representation> instance appears in more than one branch of the aggregation.

strict_organizing_principle

If the value of the strict_organizing_principle field is SE_TRUE, each branch of this aggregation strictly complies with the organizing principle for its particular subclass. If this value is SE_FALSE, at least one branch does not strictly comply with the given organizing principle. See the organizing principle constraint for each specific subclass for details.

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Last updated: July 26, 2006