r.viewshed Computes the viewshed of a point on an elevation raster map. Raster (r.*) ParameterRaster|input|Elevation|False ParameterPoint|coordinates|Coordinate identifying the viewing position|0.0,0.0 ParameterString|observer_elevation|Viewing elevation above the ground|1.75|False|False ParameterString|target_elevation|Offset for target elevation above the ground|0.0|False|False ParameterString|max_distance|Maximum distance from the viewing point (meters)|-1|False|False ParameterNumber|refraction_coeff|Refraction coefficient|0.0|1.0|0.14286|False ParameterNumber|memory|Amount of memory to use in MB|1|None|500|False *ParameterBoolean|-c|Consider earth curvature (current ellipsoid)|False *ParameterBoolean|-r|Consider the effect of atmospheric refraction|False *ParameterBoolean|-b|Output format is invisible = 0, visible = 1|False *ParameterBoolean|-e|Output format is invisible = NULL, else current elev - viewpoint_elev|False OutputRaster|output|Intervisibility