Celestial Navigation · Star Selection
For the strongest fix from a round of star sights, the bodies should be chosen so their azimuths are:
- AWell spread around the horizon (e.g., about 120° apart for three stars)✓ Correct
- BAll within 10 degrees of each other
- CAll near the zenith
- DAll on the same bearing
Explanation
Lines of position cross most sharply when azimuths are widely separated; three stars near 120° apart give a small, well-conditioned fix. Bodies close in azimuth give a weak, elongated fix.
Authority: Bowditch (Pub. No. 9), selection of bodies
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