Celestial Navigation · Sight Reduction — Z to Zn North Latitude
In north latitude with LHA less than 180°, the azimuth angle Z is converted to true azimuth Zn by:
- AZn = 360° minus Z✓ Correct
- BZn = Z
- CZn = 180° minus Z
- DZn = 180° plus Z
Explanation
North latitude: if LHA > 180°, Zn = Z; if LHA < 180°, Zn = 360° − Z. (South latitude uses Zn = 180° − Z for LHA > 180° and Zn = 180° + Z for LHA < 180°.)
Authority: Pub. 229 / 249 conversion rules
Practice the full Celestial Navigation bank
Free spaced-repetition quizzing across 2550 USCG exam questions — it schedules your reviews so the ones you miss come back until they stick.
Related Celestial Navigation questions
- 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:
- The Nautical Almanac
Approximately how fast does the GHA of the Sun increase with time?