You observe the lower limb of the Sun at a...

Question 1 of 2707066636eea28f7522a1c51b402

You observe the lower limb of the Sun at a sextant altitude (hs) of 31°31.5' on 6 March. The index error is 2.5' on the arc. The height of eye is 76 feet. What is the observed altitude (Ho)?

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Question 1 of 27070

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You observe the lower limb of the Sun at a sextant altitude (hs) of 31°31.5' on 6 March. The index error is 2.5' on the arc. The height of eye is 76 feet. What is the observed altitude (Ho)?

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🔍 Key Concepts

• Index error: how to apply "on the arc" vs "off the arc" to hs • Dip (height of eye correction) from 76 feet and its sign • How to convert sextant altitude (hs) to observed altitude (Ho) using the standard correction sequence

💭 Think About

• First adjust hs for index error: should you add or subtract when the error is "on the arc"? • Next apply dip: with a positive height of eye, does dip increase or decrease the apparent altitude? • After applying index error and dip, compare your intermediate altitude to the choices—are they higher or lower than the original hs?

✅ Before You Answer

• Be sure you are treating 2.5' on the arc with the correct sign before moving on • Use the correct dip value for 76 feet from the Nautical Almanac tables (or approximate formula) and note its sign • Confirm that you have only applied index correction and dip—no refraction or semi‑diameter corrections yet, since the problem asks for Ho, not Ho from Hs with all almanac corrections