On 4 July you observe the lower limb of the Sun at a sextant altitude (hs) of 25°29.8'. The index error is 3.1' off the arc. The height of eye is 48 feet (14.6 meters). What is the observed altitude (Ho)?

Question

On 4 July you observe the lower limb of the Sun at a sextant altitude (hs) of 25&deg;29.8'. The index error is 3.1' off the arc. The height of eye is 48 feet (14.6 meters). What is the observed altitude (Ho)?

Accepted Answer

Option B: 25&deg;40.2'. Observed altitude requires applying sextant corrections in sequence per Bowditch. Index error 'off the arc' is added. Dip is subtracted based on height of eye. Semi-diameter and refraction/parallax corrections yield the final Ho of 25&deg;40.2'.

On 4 July you observe the lower limb of the Sun at a sextant altitude (hs) of 25&deg;29.8'. The index error is 3.1' off the arc. The height of eye is 48 feet (14.6 meters). What is the observed altitude (Ho)?

On 4 July you observe the lower limb of the Sun at a sextant altitude (hs) of 25°29.8'. The index error is 3.1' off the arc. The height of eye is 48 feet (14.6 meters). What is the observed altitude (Ho)?