Question 1691Navigation General70% to pass
When applying a dip correction to the sighted sextant angle (hs), you always subtract the dip because you are correcting _______________.
AI Explanation
The correct answer is C) hs to the sensible horizon.
When taking a sextant observation, the sighted sextant angle (hs) is the angle between the celestial body and the visible horizon. However, the visible horizon is not the same as the sensible horizon, which is the true horizon taking into account the effects of atmospheric refraction. The dip correction is used to adjust the sighted angle (hs) to account for the difference between the visible and sensible horizons. Since the dip is a negative value, it is subtracted from the sighted angle (hs) to correct it to the sensible horizon.
The other options are incorrect because option A) involves correcting the observed altitude (Ho) rather than the sighted angle (hs), option B) is not the correct correction to apply, and option D) refers to the visible horizon rather than the sensible horizon.
Related Questions
#1689 Because the actual center of some planets may differ from the observed center, the navigator applies a correction known as the _______________.#1690 A phase correction may be applicable to correct the sextant altitude correction of _______________.#1692 Apparent altitude is sextant altitude corrected for _______________.#1693 A parallax correction is NOT applied to observations of the _______________.#1694 When correcting the sextant altitude to apparent altitude you are correcting for inaccuracies in the reference level and _______________.