1. What is Radar Horizon?

The radar horizon is the maximum distance at which a radar can detect objects due to the curvature of the Earth. It's the point where the radar beam becomes tangent to the Earth's surface.

2. How Does the Calculator Work?

The calculator uses the radar horizon formula:

Where:

• \( d \) — Radar horizon distance (meters)
• \( R \) — Earth's radius (default 6,371,000 meters)
• \( h \) — Antenna height above ground (meters)

Explanation: The formula accounts for the Earth's curvature and the height of the radar antenna. Higher antennas can see farther due to reduced curvature obstruction.

3. Importance of Radar Horizon Calculation

Details: Knowing the radar horizon is crucial for radar system design, placement of radar stations, and understanding detection limits for air traffic control, weather monitoring, and military applications.

4. Using the Calculator

Tips: Enter antenna height in meters. Earth's radius is pre-filled with standard value (6,371,000 m) but can be adjusted for different atmospheric refraction conditions.

5. Frequently Asked Questions (FAQ)

Q1: Why does Earth's curvature affect radar?
A: Radar waves travel in straight lines, so the Earth's curvature creates a "horizon" beyond which objects are hidden.

Q2: Can radar see beyond the horizon?
A: Under normal conditions no, but atmospheric refraction can sometimes extend the effective range slightly.

Q3: How does antenna height affect range?
A: Higher antennas increase range non-linearly - doubling height increases range by about 41%.

Q4: What's the typical radar horizon for aircraft?
A: For an aircraft at 10,000 m (33,000 ft), the radar horizon is about 360 km (225 miles).

Q5: Does this apply to shipboard radar?
A: Yes, but ships have much lower antenna heights, resulting in shorter radar horizons (typically 20-30 km).