Celestial Navigation · Meridian Altitude
At local apparent noon, latitude is found from the Sun's meridian altitude using:
- ALatitude = 90° − Ho ± declination (per the zenith distance and declination relationship)✓ Correct
- BLatitude = GHA + longitude
- CLatitude = Ho + dip
- DLatitude = LHA − declination
Explanation
At meridian passage the zenith distance is 90° − Ho; latitude equals the zenith distance combined with declination according to whether the body bears north or south. This is the classic noon sight for latitude.
Authority: Bowditch (Pub. No. 9), meridian altitude / latitude at LAN
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