Class

• <DRM Property Value>

Superclass

• <DRM Property>

Subclass

• None.

Definition

An instance of this DRM class specifies a property of the attributed DRM object and its value in terms of

1. its meaning (specified using an EAC, 5.2.7.23 Index_Code, or 5.2.7.54 Variable_Code),
2. its unit of measurement (such as metres),
3. and its data storage type (such as 5.2.3.8 Integer).

The value field specifies the value of the given property.

Class diagram

Figure 6.251 — DRM_Property_Value

Constraints

• <DRM Property Characteristic> constraints
• <DRM Property> constraints
• Publishable object

Example(s)

• The <DRM Property Value> instances of a representation of a lake might include the EAC_SURFACE_MATERIAL_TYPE of the lake.

• Consider the man-made materials that can be found on any surface, such as cloth, carpet, asphalt, silk, metal, and natural materials, such as wood. To specify the material making up a wooden wall represented by a <DRM Polygon> instance, the data provider represents it as depicted in Figure 6.252.

  

  Figure 6.252 — <DRM Property Value> example

• Consider a <DRM Areal Feature> instance representing a surface covered with vegetation. To specify the type of vegetation, the data provider gave it a <DRM Property Value> component with a meaning of EAC_VEGETATION_TYPE, and the value specifying the exact type of vegetation.

• Consider a <DRM Areal Feature> instance labeled as “Red Field”, because the surface represented has clay soil present. To describe the soil composition at some point or for some surface, <DRM Property Value> instances are used, so a <DRM Property Value> instance of the appropriate attribute is attached to the <DRM Areal Feature> instance.

• Consider acoustic response (that is, changes to characteristics of objects in response to acoustic stimuli) such as the resonant frequency of a plate, response (such as echo, phase shift, absorption, diffraction), or frequency.

• Consider electromagnetic emission, that is, the emission characteristics of a geometric object or feature, including the electromagnetic wavelengths, amplitudes, and directionality. Examples include

  1. The thermal signature of a rock at noon is described by its electromagnetic emission.
  2. The headlight of a truck.

• Consider electromagnetic response (that is, changes to characteristics of objects in response to electromagnetic stimuli). Some examples of such properties include reflective and specular characteristics of a surface.

• Consider hydrology (that is, an attribute describing some aspect of the flow of water at a location or on a surface). For the <DRM Polygon> instances that represent Salmon Creek, an example hydrology property represented by <DRM Property Value> instances is the average speed of currents in the stream bed.

• <DRM Property Value> instances can provide metrics or measurements that relate to scalar properties, such as the elevation at a particular location.