Celestial Navigation · Hour Angle — LHA
Local hour angle (LHA) is found from Greenwich hour angle (GHA) by:
- ALHA = GHA + east longitude, or GHA − west longitude✓ Correct
- BLHA = GHA + declination
- CLHA = GHA − dip
- DLHA = GHA × latitude
Explanation
Add east longitude to GHA and subtract west longitude to get LHA (adding or subtracting 360° as needed to keep it 0–360°). LHA measures the body's hour angle west of the observer's meridian.
Authority: Bowditch (Pub. No. 9), hour angle relationships
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