Digital terrain analysis

Question 1

digital terrain analysis

Answer 1

Process that quantitively describes the terrain or features of the land
Aka geomorphological analysis, landform analysis, landform parameterization
Produces terrain parameters (slope, aspect)
Produces spatial features (houses, trees, roads)

Question 2

Point clouds

Answer 2

Collection of points that represent a 3d shapes of features (trees and buildings)

Question 3

Data sources for DTA

Answer 3

Resolution: number of pulses per unit area
Accuracy: vertical accuracy (15-20cm)/horizontal accuracy (0.3-1m)
Intensity: strength of returns

Question 4

Digital surface model (DSM)

Answer 4

Contains elevation information about all features in the landscape, such as buildings, vegetation and other structures

Question 5

Digital terrain model (DTM)

Answer 5

Contains elevation info about the bare earth surface without the influence of vegetation or human structures

Question 6

Digital elevation model (DEM)

Answer 6

Could be USM or DTM

Question 7

Applications of DTA

Answer 7

Vegetation mapping and structure
Coastline and shoreline monitoring
Volumetric analysis (landfills)

Question 8

Strengths of DTA

Answer 8

All data georeferenced
Acquire accurate 3d info
High level of accuracy
Less labour intensive
Light independence

Question 9

DTA Limitations

Answer 9

High cost
Limited spatial and temporal coverage
Hard to penetrate - very dense canopy
Require precise sensor alignment
Very large datasets