The SEDRIS Data Representation Model
APPENDIX A - Classes
Primitive Feature

Abstract Class Name: Primitive Feature

Superclass - <Feature Representation>

Subclasses

Definition

An instance of this DRM class is a <Feature Representation> instance that is not hierarchically structured.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

Example

See individual subclasses for examples.

FAQs

What determines whether a <Feature Representation> instance is represented as a <Point Feature> instance, a <Linear Feature> instance, or an <Areal Feature> instance?

This is primarily determined by the dimensions of the <Feature Representation> instance, in conjunction with the nature of the <Feature Representation> instance, the resolution of the source imagery from which the feature was extracted, and the intended use of the extracted feature data. A long, narrow feature will be extracted as a <Linear Feature> instance, representing the centreline of the actual feature, with EAC_WIDTH information. A very small feature will be extracted as a <Point Feature>, with EAC_LENGTH and EAC_WIDTH information, or possibly EAC_RADIUS information.

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

This class has no inherited field elements.

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

These components support attributes for derived objects; that is, they are used only to specify texture mapping information for geometry that is derived from the <Primitive Feature> instance by the consumer. These <Image Mapping Function> components shall use <Image Anchor> components to specify the mapping.


Presentation_Domain

The <Presentation Domain> component is needed because, in many cases, a <Primitive Feature> instance may be significant only for a particular domain, such as radar.


Prev: Primitive Colour. Next: Primitive Geometry. Up:Index.

Last updated: July 26, 2006 Copyright © 2006 SEDRIS