GEOGRAPHY & CARTOGRAPHY CALCULATOR
Visibility Analysis
A precise tool.
What is the Visibility Analysis & How does it work?
Line‑of‑sight (LOS) analysis determines whether two ground points can see each other directly, taking into account the Earth’s curvature and any elevation of the terrain.
Because the Earth is approximately spherical, each point has a geometric horizon. The distance to this horizon is given by the formula
d = \sqrt{2 R h + h^2}
d = horizon distance (m)
If the straight‑line distance between the two points is less than or equal to the sum of their individual horizon distances, the LOS is unobstructed; otherwise the curvature blocks the view.
Parameters
Result
—
Frequently Asked Questions
How do I calculate the horizon distance for a given height?
Use the formula d = sqrt(2 R h + h^2), where R is the Earth's radius (approximately 6371 km) and h is your height above ground level in meters.
What factors affect line-of-sight visibility?
Line-of-sight visibility is affected by the distance between points, their heights above ground level, and any terrain elevation that may obstruct the view.
Can I use this calculator for long-distance observations?
Yes, you can use this calculator to estimate visibility over long distances, but keep in mind that atmospheric conditions like fog or haze can also affect visibility.
What is the difference between geometric horizon and actual visible horizon?
The geometric horizon is the theoretical line where Earth's curvature meets your eye level. The actual visible horizon may be lower due to atmospheric refraction and other factors.
How accurate is this LOS analysis for urban areas with tall buildings?
This calculator provides a basic estimate suitable for open terrain. For urban areas, additional factors like building heights and city layout must be considered for accurate visibility analysis.
Results are for informational purposes only and do not constitute professional advice.