Visibility Light Source

The light source visibility indicator allows to evaluate at each grid, the number of light sources visible by an observatur at a given height.
It requires several data calculated in tab 1 and 2, to then calculate the results in tab 3.

Viewshed

Calcul a visibility map raster which indicates for each pixel the number of visible lights sources according to the relief, the building and possibly the vegetation.

Input parameters

- Extent zone : Extent of the study area used to delimit the treatments.
- Light points extraction : Vector layer of light points resulting from a processing carried out on the night satellite image.
- Height light source field : Field representing the height of the light source in the light points layer (optional).
- Source light height : Height of the source, if no field selected, 6 meters by default.
- Observer height : Height of the observer, 0, 1 or 6 meters.
- Radius field for visibility : Field indicating the maximum visibility distance in the light points layer (optional).
- Radius for visibility : Maximum visibility distance, if no field selected, in meters.
- DSM : Digital Surface Model to take into account to calculate the visibility.
- Raster buildings vegetation : Raster layer of buildings and the vegetation if present.

Output data

- Raster Viewshed : Raster layer of viewshed which indicates the number of visible sources per pixel.
Save to temporary file if not filled.

This processing uses the plugin code of Visibility Analysis :
https://www.zoran-cuckovic.from.hr/QGIS-visibility-analysis