Celestial Navigation · Moon
The Moon requires a 'v' correction to its GHA because its:
- ADeclination never changes
- BRate of change of GHA differs from the standard hourly rate✓ Correct
- CSemidiameter is fixed
- DParallax is zero
Explanation
The Moon moves rapidly and irregularly, so a positive 'v' correction is interpolated and added to bring the hourly GHA to the exact time. The Moon also needs the largest parallax and semidiameter corrections.
Authority: The Nautical Almanac, Moon pages and v correction
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