Elevation Data Flashcards
1
Q
DEM
A
Digital Elevation Model
raster of Earth’s bare topographical surface
2
Q
DTM
A
Digital Terrain Model
type of DEM
does not include natural or manufactured features, but includes features of natural terrain (ridges and rivers, etc)
3
Q
DSM
A
Digital Surface Model
type of DEM
includes natural and manufactured features in model
4
Q
TIN
A
Triangulated Irregular Network
triangulate a set of points (vertices/nodes) to form a network of triangles
5
Q
Breaklines
A
lines of constant elevation imposed in a TIN
roads, rivers, faults, ridges
6
Q
DEM characteristics
A
- simple
- requires resampling for irregular data
- can miss complex topography
- data redundancy
- Raster
7
Q
TIN characteristics
A
- accepts randomely distributed elevation data
- incorporation of breaklines to enforce elevation
- accepts spot heights (peaks/troughs)
- model complexity scales to terrain complexity
- Vector
8
Q
Terrain Analysis types
A
slope and aspect
9
Q
slope
A
rate of elevation change per pixel (degrees or percent)
10
Q
aspect
A
the direction that the slope faces
11
Q
what form does most data come in?
A
DEM format (not TIN)
