Line of sight
Where can you see
Where can you see Mont Blanc
The map shows where Mont Blanc can theoretically be visible within the calculated area, based on terrain and Earth's curvature.
Calculated radius: 100 kmTerrain remains visible beneath the result
Check your viewpoint
Can you see Mont Blanc from where you are?
Choose an observation point and Sightelo will calculate the exact line of sight.
Example lines of sight
How do distance and terrain affect the view?
Open a reproducible Sightelo analysis with its terrain profile.
Line of sight
Mont Blanc from Annecy
Annecy city centre, France → Mont BlancView analysisLine of sight
Mont Blanc from Geneva
Parc de la Perle du Lac lakeside, Geneva, Switzerland → Mont BlancView analysisUnderstand the map
Why isn't visibility a simple circle?
Terrain
Mountains and ridges can block the line of sight.
Earth's curvature
At long distances, Earth's curvature becomes significant.
Elevation
A higher observation point can dramatically increase visibility.
How was this visibility map calculated?
Sightelo samples observation points around the summit and calculates their line of sight using terrain elevation, Earth curvature and standard atmospheric refraction.
- Terrain data
- Copernicus DEM 90, refined with DEM 30 when terrain or the horizon makes the result uncertain. The local threshold is at most one third of the sight-line elevation change, capped at 30 m for DEM 90 and 10 m for DEM 30.
- Earth curvature
- Included
- Atmospheric refraction
- k = 0.13
Have another mountain in mind?