Celestial Navigation · Amplitude
An amplitude observation taken at sunrise or sunset is used to find:
- ALatitude
- BThe equation of time
- CLongitude
- DCompass error, by comparing the observed bearing to the computed true amplitude✓ Correct
Explanation
The body's true amplitude (angular distance from east/west, a function of declination and latitude) is compared to the observed compass bearing as the body's center is on the visible horizon, yielding compass error.
Authority: Bowditch (Pub. No. 9), amplitudes; Pub. No. 229 amplitude tables
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