The line of sight calculator allows you to estimate the maximum distance over which two antennas can see each other directly, without obstacle.
This tool is widely used in RF engineering, telecommunications and for planning radio or microwave links.
Formula used
dₗ = 3.57 × √h
dᵣ = 4.12 × √h
Or :
dₗ = line of sight distance (km)
dᵣ = service range or radio horizon (km)
h = antenna height (meters)
Explanation
These formulas show the relationship between the height of an antenna and the distance to the visible horizon.
The first formula ( dₗ ) represents the geometric line of sight, while the second ( dᵣ ) takes into account the average atmospheric refraction,
which gives a more realistic estimate of the radio range.
So, the higher the antenna, the greater the viewing distance and signal coverage.
Calculation example
For an antenna of h = 10 meters :
dₗ = 3.57 × √10 ≈ 11.29 km
dᵣ = 4.12 × √10 ≈ 13.03 km
This means that the radio horizon extends to approximately 13 kilometers for an antenna 10 meters high.
Benefits and Use
- Allows you to evaluate the visual and radio range between two communication points.
- Useful for planning wireless links, communications towers and microwave systems.
- Helps determine the minimum height needed to ensure a clear line of sight.
- Facilitates the design of reliable RF networks by limiting gray areas or interference.
