Celestial Navigation · The Nautical Almanac — d Correction
The 'd' value next to a body's declination in the daily pages is used to:
- ACorrect the GHA for the equation of time
- BInterpolate the declination for minutes and seconds of GMT (its hourly rate of change)✓ Correct
- CConvert SHA to GHA
- DApply the dip correction
Explanation
The d value is the hourly rate of change of declination. It is taken to the Increments and Corrections (yellow) pages with the minutes/seconds of GMT to find the d correction, applied to the tabulated declination in the direction declination is changing.
Authority: Nautical Almanac, daily pages and increments/corrections
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- The Nautical Almanac — d Correction
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