1 Altitude Corrections Quiz Q & A Junior Navigation Chapter 4

2 1. Dip correction is the angular difference between the visible horizon and a true horizontal. a. True b. False

3 2. A ship's captain takes a sight from the ship's rigging with a HE of 54 feet. His mate takes a sight from the deck of the ship with a HE of 18 feet. For which HE will the dip correction be greatest? HE of 54 feet

4 3. Find the dip correction: HE Correction 18 ft ____ 22 ft____ 72 ft____ -4.1' -4.5' -8.2'

5 4. For the following data, determine main sextant altitude corrections: Body Date ha Sun UL 21 June 17° 32.1' Sun LL 29 Sept 43° 46.0' Sun UL 29 Sept 43° 46.0' Sun LL 10 Mar 61° 41.6' Main ' +15.0' -16.8' +15.7'

6 Altitude Corrections JN Quiz Chapter 4 Problem 5 Refraction is minimal for: a. daylight observations. b. low-altitude sights. c. star sights. d. high-altitude sights.

7 Altitude Corrections JN Quiz Chapter 4 Problem 6 Parallax is minimal for: a. daylight observations. b. moon sights. c. star sights. d. sun lower-limb sights.

8 Altitude Corrections JN Quiz Chapter 4 Problem 7 The main correction for an Sun LL sight is subtracted from ha. a. True b. False

9 Altitude Corrections End of Quiz Q & A Junior Navigation Chapter 4