1. What is the Visible Horizon Distance?

The visible horizon distance is the maximum distance an observer can see due to the Earth's curvature. It represents how far away objects become hidden below the horizon based on the observer's height above sea level.

2. How Does the Calculator Work?

The calculator uses the horizon distance formula:

Where:

• \( R \) — Earth's radius (approximately 6371 km)
• \( h \) — Observer's height above sea level (converted to km)

Explanation: The formula accounts for the Earth's curvature and calculates how far an observer can see based on their elevation above the Earth's surface.

3. Importance of Horizon Distance Calculation

Details: Calculating horizon distance is crucial for navigation, aviation, maritime operations, and understanding geographical visibility limitations. It helps determine how far landmarks, ships, or aircraft are visible from different elevations.

4. Using the Calculator

Tips: Enter Earth's radius in kilometers (standard value is 6371 km) and observer's height in meters. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the standard Earth radius value?
A: The standard Earth radius is approximately 6371 kilometers, though it varies slightly due to Earth's oblate spheroid shape.

Q2: How does height affect visible distance?
A: The higher the observer, the farther they can see. Distance increases with the square root of height.

Q3: Does atmospheric refraction affect the calculation?
A: Yes, atmospheric refraction typically increases the visible distance by about 8% compared to the geometric calculation.

Q4: What are typical horizon distances?
A: For a person standing at sea level (1.7m height), horizon is about 4.7 km away. From 100m elevation, it's about 36 km.

Q5: Can this formula be used for other planets?
A: Yes, by substituting the appropriate planetary radius, the formula can calculate horizon distances on other celestial bodies.