Viewshed Analysis

The DK 11.8 brings viewshed and above-ground-level (AGL) visibility analysis.

Performing this analysis requires a digital elevation model of the subject terrain in the form of a grid file. The analysis takes into account the curvature of the earth, refractivity, observer height (e.g., height of a radio antenna tower), and terrain fixed offset (e.g., level of forest growth, etc.).

Typical uses of viewshed analyses include:

  • calculate required height of a fire lookout tower to cover a defined area of forested terrain,
  • calculate optimal location for next communication tower,
  • visual influence analysis (e.g., determine number of wind turbines visible from a particular location, etc.),
  • calculate number of times a particular point or object is visible from a length of road.

Support for Fresnel zones will be added soon.

Read more about support for viewshed and AGL analysis in the online DK Documentation.

Viewshed visibility analysis example.
Green color represents areas visible from at least one of the radio towers.

Viewshed frequency analysis example.
Color ramp (red to green); red color represents areas visible from only one radio
antenna tower;  green color represents areas visible from all radio towers.


Above-ground-level (AGL) analysis example.
Color ramp (green to red) represents the additional height (e.g., for an antenna
placement) required to guarantee visibility from at least one of the antenna towers.

Posted: October 20, 2017
Filed under: ANALYSES, DK