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

Study

Question 1 of 2066636eea28f7522a1c51b409

You observe the lower limb of the Sun at a sextant altitude (hs) of 38°07.5' on 8 August. The index error is 5.2' off the arc. The height of eye is 72 feet (22 meters). What is the observed altitude (Ho)?

Back

Question 1 of 20

66636eea28f7522a1c51b409

No comments yet

Be the first to share your thoughts!

If the question has a related picture, it will appear here.

🔍 Key Concepts

• Index error and index correction – how to change the sign when the sextant reads "off the arc" • Dip correction for height of eye – why it is always subtracted and how its size relates to height of eye • Total altitude correction for the Sun’s lower limb – how refraction and semi‑diameter combine for a mid‑altitude Sun

💭 Think About

• Start from the given sextant altitude (hs). How do you get the sextant altitude corrected for index error and dip (Ho ≈ apparent altitude)? What is the correct order of corrections? • If the index error is 5.2' off the arc, should the index correction be added to or subtracted from hs? How many minutes does that change hs by? • At about 38° altitude for the Sun, is the combined refraction + semi‑diameter correction a small (1–2') or larger (5–10'+) effect? In which direction does it move the final Ho compared with the apparent altitude?

✅ Before You Answer

• Be sure you convert index error → index correction correctly before applying it. • Confirm that dip is always negative (subtracted) and check its approximate size for a 72 ft (22 m) eye height. • After applying all corrections, compare how many total minutes of arc you have added or subtracted from 38°07.5' and see which answer choice is within about 1–2' of that estimate.

👋 Hi! I'm Genie, your AI study assistant. How can I help you with this question?

Quick actions

— No credit card needed