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Azimuth / Altitude Demonstrator
HK defaultObserver in Hong Kong
Altitude measures height above the horizon (0° = horizon, 90° = overhead). Azimuth is compass direction (0° = North, 90° = East).
Horizon diagram
Before you start
Alt/Az is the natural way to describe where something is in the sky from your location: how high up and which compass direction.
Key idea
Altitude (0–90°) measures height above the horizon. Azimuth (0–360°) is compass direction from north through east.
What you see
- Circular horizon diagram with N/E/S/W
- Markers for Sun, Moon, and Polaris
- Your adjustable position in blue
Try this
- Find Polaris — it sits at altitude ≈ your latitude (22.4° in HK)
- Set azimuth to 90° (east) and altitude to 0° — that's the eastern horizon
- Pick a date and compare Sun vs Moon positions
Why it matters in Hong Kong
Hong Kong observers see Polaris low in the north — only about 22° above the horizon.
Common mistakes
- Measuring azimuth from south instead of north
- Confusing altitude with declination
Glossary
- Altitude
- Angle above the horizon.
- Azimuth
- Compass bearing, 0° = North, 90° = East.