Celestial Navigation · Sight Reduction
Pub. No. 249 (Sight Reduction Tables for Air Navigation), Volume 1, is especially convenient because it:
- ACovers only the Sun
- BEliminates the need to know the date
- CLists pre-computed altitude and azimuth for seven selected stars by LHA Aries✓ Correct
- DRequires no assumed position
Explanation
Pub. 249 Vol. 1 tabulates Hc and Zn for seven selected (well-placed, bright) stars as a function of latitude and LHA Aries, making twilight star fixes fast. Vols. 2 and 3 handle bodies by declination.
Authority: Pub. No. 249 (Sight Reduction Tables)
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Related Celestial Navigation questions
- Sight Reduction
The altitude intercept is found from a = Ho − Hc. When Ho is greater than Hc, the intercept is plotted:
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When reducing a sight with Pub. No. 229, the assumed position is chosen so that:
- Sight Reduction
A celestial line of position is drawn:
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A single celestial observation by itself provides:
- Time
The Nautical Almanac tabulates the positions of celestial bodies against which time standard?
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A vessel in west longitude has a zone description of +5. To convert zone time to UT you must: