Celestial Navigation · Polaris — Latitude
In the Northern Hemisphere, the latitude of the observer is found from Polaris by:
- ADoubling the altitude of Polaris
- BReading the GHA of Polaris directly as the latitude
- CTaking the corrected observed altitude of Polaris and applying the a0, a1, a2 corrections from the Nautical Almanac✓ Correct
- DSubtracting Polaris's altitude from 90°
Explanation
Latitude ≈ Ho of Polaris + a0 + a1 + a2 (the three small corrections tabulated against LHA Aries, month, and latitude). Polaris lies within about 1° of the celestial pole, so its corrected altitude closely equals the observer's latitude.
Authority: Nautical Almanac, Polaris (Pole Star) Tables
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