GEOGRAPHY & CARTOGRAPHY CALCULATOR
Distanceantenna Height Range
A precise tool.
What is the Distanceantenna Height Range & How does it work?
Radio waves travel in straight lines, but the Earth’s curvature limits how far a signal can be seen from a given height. This effect is called the radio horizon, and it grows as the square‑root of the antenna’s elevation above the ground. When both the transmitting antenna and the receiving antenna are elevated, each contributes its own horizon distance. Adding those distances gives the total line‑of‑sight range, which is a good first‑order estimate for VHF, UHF and many microwave links. The classic empirical formula for the radio horizon (in kilometres) is derived from the geometry of a sphere and a standard refraction factor. It is widely used in planning broadcast towers, cellular sites and point‑to‑point microwave links.
d = 3.57\left(\sqrt{h_1}+\sqrt{h_2}\right)
d = radio range (km), h_1 = antenna height (m), h_2 = receiver height (m)
Parameters
Result
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Frequently Asked Questions
What is the formula for calculating the radio horizon?
The radio horizon distance can be calculated using the formula: d = sqrt(2 * R * h), where d is the distance, R is the radius of the Earth (approximately 6371 km), and h is the antenna height in meters.
How does the Earth’s curvature affect radio wave propagation?
The Earth’s curvature limits how far a signal can be seen from a given height. This effect is called the radio horizon, which grows as the square root of the antenna’s elevation above the ground.
Can you explain what line-of-sight range means in this context?
Line-of-sight range refers to the maximum distance that a signal can travel in a straight line between two antennas without being obstructed by the Earth’s curvature. It is calculated by adding the horizon distances of both transmitting and receiving antennas.
How accurate is this calculator for VHF, UHF, and microwave links?
This calculator provides a good first-order estimate for VHF, UHF, and many microwave links. However, factors such as atmospheric conditions, terrain, and obstructions can affect the actual range.
What units should I use when entering antenna heights?
When entering antenna heights, you should use meters. The calculator will then provide the line-of-sight range based on this input.
Can this calculator be used for satellite communications?
No, this calculator is specifically designed for ground-based radio wave propagation and does not account for satellite communications or orbital mechanics.
How do I interpret the result given by the calculator?
The result from the calculator represents the total line-of-sight range between two antennas. This distance indicates how far a signal can travel without being obstructed by the Earth’s curvature, assuming no other factors are present.
Results are for informational purposes only and do not constitute professional advice.