Abstract Class Name: Primitive Feature

Superclass - <Feature>

Subclasses

• <Areal Feature>
• <Linear Feature>
• <Point Feature>

Definition

A <Feature> that is not hierarchically structured, i.e., a <Point Feature>, <Linear Feature>, or <Areal Feature>.

Primary Page in DRM Diagram:

• 8

Secondary Pages in DRM Diagram:

Example

See individual subclasses for examples.

FAQs

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

This is primarily determined by the dimensions of the feature, in conjunction with the nature of the feature, 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>, representing the centreline of the actual feature, with a width field. A very small feature will be extracted as a <Point Feature>, with length and width fields, or possibly a radius field.

Constraints

• <<No Attribute Conflicts>>
• <<Non Crossing Aggregations>>
• <<Non Crossing Associations>>
• <<Precedence of Attribute Set Index>>
• <<Colour Mapping Restrictions>>
• <<Image Mapping Functions and Texture Coordinates>>

Associated with (two-way)(inherited)

• zero or more <Feature> instances (notes)
• zero or more <Geometry Hierarchy> instances (notes)
• zero or more <Property Grid> instances (notes)

Composed of (two-way)(inherited)

• zero or more {ordered} <Attribute Set Index> instances
• zero or one <Classification Data> instance
• zero or more <Label> 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

Composed of (two-way)

• zero or more <Colour> instances
• zero or more {ordered} <Image Mapping Function> instances (notes)
• zero or one <Presentation Domain> instance (notes)
• zero or one <Spatial Domain> instance

Composed of (two-way metadata)(inherited)

• zero or one <Access> instance
• zero or more <Browse Media> instances
• zero or more <Cross Reference> instances
• zero or one <Data Quality> instance
• zero or one <Keywords> instance
• zero or one <Point Of Contact> instance
• zero or one <Time Constraints Data> instance

Component of (two-way)(inherited)

• zero or more <Union Of Features> instances

Inherited Field Elements

Notes

Associated with Notes

Feature

 An association between two <Feature> instances indicates
 that they are alternate representations of the same
 environmental object.

Geometry_Hierarchy

 An association between a <Geometry Hierarchy> instance and a
 <Feature> instance indicates that the <Geometry Hierarchy>
 and the <Feature> are alternate representations of the same
 environmental object.

Property_Grid

 An association between a <Property Grid> instance and a
 <Feature> indicates that the <Feature> and the <Property Grid>
 (or some specific cell data within that <Property Grid>) are
 alternate representations of the same environmental object.
 Each associated <Property Grid> will indicate which is the case.

Composed of Notes

Image_Mapping_Function

 Supports "attributes for derived objects."
 That is, these components are used only to specify
 texture mapping information for geometry that
 is derived from the <Primitive Feature> by the consumer.
 These <Image Mapping Functions> shall use
 <Image Anchor> components to specify the mapping.

Presentation_Domain

 This is needed because in many cases, a <Primitive Feature> may be
 significant only for a particular domain, e.g. radar.