You observe the lower limb of the Sun at a sextant altitude (hs) of 75°12.3' on 6 August. The index error is 1.5' off the arc. The height of eye is 32 feet (9.8 meters). What is the observed altitude (Ho)?

Question

You observe the lower limb of the Sun at a sextant altitude (hs) of 75&deg;12.3' on 6 August. The index error is 1.5' off the arc. The height of eye is 32 feet (9.8 meters). What is the observed altitude (Ho)?

Accepted Answer

Option B: 75&deg;24.0'. Per Bowditch reduction tables, index error 'off the arc' is added to sextant altitude. Subtracting dip for a 32-foot height of eye, adding lower limb semidiameter, and subtracting refraction yields the final observed altitude of 75&deg;24.0'.

You observe the lower limb of the Sun at a sextant altitude (hs) of 75&deg;12.3' on 6 August. The index error is 1.5' off the arc. The height of eye is 32 feet (9.8 meters). What is the observed altitude (Ho)?

You observe the lower limb of the Sun at a sextant altitude (hs) of 75°12.3' on 6 August. The index error is 1.5' off the arc. The height of eye is 32 feet (9.8 meters). What is the observed altitude (Ho)?