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

Class Name: Perimeter Related Features

Superclass - <Aggregate Feature>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class is an <Aggregate Feature> instance that spatially organizes its <Feature Hierarchy> components into a collection of (potentially) irregularly shaped regions, each defined by a <Perimeter Data> instance. That is, each <Feature Hierarchy> component is contained within the perimeter area specified by the <Perimeter Data> instance associated with that component.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

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

Example

  1. Consider a thematic coverage in which the spatial extent forms a collection of tiles, where some of the tiles (due to shorelines) have irregular shapes. Consequently, this coverage is represented by a <Perimeter Related Features> instance, in which the boundary of each tile can be correctly represented by a <Perimeter Data> link object.

    NOTE  While a rectangular tile can be described by a <Perimeter Data> link object with four <Location> components, an irregularly shaped tile may require a larger number of <Location> components.

FAQs

May the regions defined by the <Feature Hierarchy> components of a <Perimeter Related Features> instance overlap?

See <<Perimeter Related Organizing Principle>>

May the same <Feature Representation> instance be contained within more than one <Feature Hierarchy> component of a <Perimeter Related Features> instance?

See <<Perimeter Related Organizing Principle>>

Does each <Feature Hierarchy> component of a <Perimeter Related Features> instance form an independent topological surface?

Normally, yes, in which case each <Feature Hierarchy> component has its own <Feature Topology Hierarchy> component. However, the <Feature Topology> instances in all the components may also form a single topological surface, in which case only the <Perimeter Related Features> instance itself has such a topology hierarchy.

Constraints

Associated to (one-way) (inherited)

Associated by (one-way) (inherited)

Composed of (two-way) (inherited)

Composed of (two-way)

Composed of (two-way metadata) (inherited)

Component of (two-way) (inherited)

Inherited Field Elements

SE_Boolean unique_descendants; 9
SE_Boolean strict_organizing_principle; 10

Notes

Associated to Notes


Feature_Representation

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

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.

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 Copyright © 2006 SEDRIS