Celestial Navigation · Star Identification — Pub 249 Vol 1
Pub. No. 249 Volume 1 (Selected Stars) helps the navigator by:
- ATabulating the GHA of the sun only
- BGiving tide predictions for selected ports
- CListing seven selected stars with their precomputed altitude and azimuth for each whole degree of LHA Aries and latitude✓ Correct
- DProviding great-circle distances between ports
Explanation
Volume 1 precomputes Hc and Zn for seven selected (favorably placed) stars at each whole degree of latitude and LHA Aries. It speeds both star selection (good distribution in azimuth and altitude) and reduction, and is reissued periodically for a given epoch.
Authority: Pub. No. 249, Volume 1 (Sight Reduction Tables for Air Navigation)
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Related Celestial Navigation questions
- Star Identification — Pub 249 Vol 1
Pub. No. 249 Volume 1 (Selected Stars) is entered with which arguments to obtain a list of suitable stars with their altitudes and azimuths?
- Time
The Nautical Almanac tabulates the positions of celestial bodies against which time standard?
- Time
A vessel in west longitude has a zone description of +5. To convert zone time to UT you must:
- Coordinates
How is the GHA of a star obtained from the Nautical Almanac?
- Coordinates
Sidereal Hour Angle (SHA) is best defined as:
- Coordinates
Declination of a celestial body is the celestial equivalent of: