Types of source data supported in terrain datasets

Photogrammetrically derived mass points

Photogrammetrically derived breaklines

GPS points

Lidar points

Sonar

Contour lines

Points, lines, polygons (mass, break, clip, erase, replace)

The thematic data types used to derive a surface are stored in the geodatabase as features with different geometry types. These types are points, multipoints, polylines, and polygons. These geometry types can be incorporated into the terrain surface in different ways. You control how a feature is used by setting its surface feature type (SFType). The following table shows the relationship of different SFTypes, types of feature classes that can be used for each SFType, height source options, and thematic data examples.

Surface feature types in terrain datasets

Surface feature type

Feature class

Z-value source in the feature class

Thematic data type examples

Mass points (x,y,z locations)

Point feature class

  • Shape geometry; x,y,z per vertex

or

  • Attribute column holding one z-value per shape
  • Spot heights
  • Survey points
  • GPS points

Multipoint feature class

  • Shape geometry; x,y,z per vertex

or

  • Attribute column holding one z-value per shape
  • Lidar points
  • Sonar points

Line feature class

  • Shape geometry; x,y,z per vertex

or

  • Attribute column holding one z-value per shape
  • Contours

Polygon feature class

  • Shape geometry; x,y,z per vertex

or

  • Attribute column holding one z-value per shape
  • Shoreline delineation

Breaklines (hard or soft)

Line feature class

  • Shape geometry; x,y,z per vertex
  • Attribute column holding one z-value per shape
  • No height source; z-values interpolated for each feature from the surface before being added
  • Contours
  • Edge of pavement
  • Water lines (streams, rivers, canals, shorelines)

Polygon feature class

  • Shape geometry; x,y,z per vertex
  • Attribute column holding one z-value per shape (such as a shoreline)
  • No height source; z-values interpolated for each feature from the surface before being added
  • Lake shoreline

Clipping polygons (hard or soft)

Polygon feature class

  • Shape geometry; x,y,z per vertex
  • Attribute column holding one z-value per shape (such as a shoreline)
  • No height source; z-values interpolated for each feature from the surface before being added
  • Study area boundary

Erase polygons (hard or soft)

Polygon feature class

  • Shape geometry; x,y,z per vertex
  • Attribute column holding one z-value per shape
  • No height source; z-values interpolated for each feature from the surface before being added
  • Lake shoreline
  • Obscured areas (dense forest canopy)

Replace polygons (hard or soft)

Polygon feature class

  • Shape geometry; x,y,z per vertex
  • Attribute column holding one z-value for all vertices in each shape
  • Water bodies

Related Topics


8/18/2010