1. What is the Solar Hour Angle Formula?

The Solar Hour Angle formula calculates the angular displacement of the sun east or west of the local meridian due to the Earth's rotation. It is a fundamental parameter in solar position calculations and astronomy.

2. How Does the Calculator Work?

The calculator uses the Solar Hour Angle formula:

Where:

• \( HA \) — Hour Angle (degrees)
• \( LST \) — Local Solar Time (hours)
• \( Solar Noon \) — Time when sun is at highest point (hours)

Explanation: The Earth rotates 15 degrees per hour (360°/24h), so the hour angle changes by 15 degrees for each hour difference from solar noon.

3. Importance of Hour Angle Calculation

Details: Hour angle is crucial for determining solar position, calculating sunrise/sunset times, designing solar energy systems, and in astronomical observations.

4. Using the Calculator

Tips: Enter Local Solar Time and Solar Noon in hours (0-24 format). Positive results indicate afternoon hours, negative results indicate morning hours.

5. Frequently Asked Questions (FAQ)

Q1: What is the range of hour angle values?
A: Hour angle ranges from -180° to +180°, with negative values before solar noon and positive values after solar noon.

Q2: How is solar noon determined?
A: Solar noon is when the sun reaches its highest point in the sky, which varies by location and date due to longitude and equation of time.

Q3: What's the difference between solar time and standard time?
A: Solar time is based on the sun's position, while standard time uses time zones. They can differ by up to 30 minutes due to longitude and daylight saving.

Q4: How accurate is this calculation?
A: The formula provides theoretical hour angle. For precise calculations, factors like atmospheric refraction and equation of time should be considered.

Q5: What are practical applications of hour angle?
A: Solar tracking systems, architectural design, agricultural planning, photography, and astronomical observations all use hour angle calculations.