1 / 11

Understanding Altitude Corrections in Navigation: Homework Q&A for Chapter 4

This resource focuses on altitude corrections vital to junior navigation, specifically addressing how factors like dip, refraction, parallax, and semi-diameter affect altitude observations. It guides students through applying altitude corrections using the Nautical Almanac, with practical exercises on calculating observed altitudes of the sun. Key questions examine how the height of the observer's eye impacts observations, correcting techniques for apparent altitude, and comparing sightings between students. Engage with essential navigation principles through problem-solving and reference material.

tanaya
Télécharger la présentation

Understanding Altitude Corrections in Navigation: Homework Q&A for Chapter 4

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Altitude Corrections Homework Q & A Junior Navigation Chapter 4

  2. Objectives: ■ Understand how the following factors affect altitude observations: dip, refraction, parallax, semidiameter. ■ Apply altitude corrections from the Nautical Almanac to observations of the sun.

  3. Practical Exercises: Problems 1. & 2. Follow the Student Manual for guidance

  4. 3. The correction for dip: a. may be either positive or negative. b. decreases in magnitude as height of eye increases. c. is always negative and increases in magnitude as height of eye increases. d. is always positive and decreases in magnitude as height of eye increases. Ref: ¶ 5

  5. 4. If an observer is taking sights from a pier in an area with a 10- foot tidal range, will his height of eye for computing altitude corrections change over a period of time? Yes. What if the observer is on a boat anchored in the same area? No. Ref: ¶ 5

  6. 5. Which of the following is used as the entering argument to enter altitude correction tables? a. Sextant altitude (hs). b. Apparent altitude (ha). c. Observed altitude (Ho). Ref: ¶ 20 - 21

  7. 6. Using the Excerpts from the Almanac, find the observed altitude (Ho) for the following:Date Body hs IC HE Ho a. 27 February Sun LL 28°15.8' +7.3' 8.0ft b. 17 August Sun UL 21°58.2' +0.7' 68.0ft 28°34.9' 21° 32.7' Solution: a.Sun LL, 22 Janhs 28°15.8' IC +7.3' Dip -2.7'ha 28°20.4 ' Main +14.5'Ho 28°34.9' Solution: b.Sun LL, 17 Aughs 21°58.2' IC +0.7' Dip -8.0'ha 21°50.9 ' Main -18.2'Ho 21°32.7' Ref: ¶ 22 - 28

  8. 7. Which of the following corrections needs to be applied in order to determine apparent altitude? a. dip and parallaxb. refraction and parallaxc. index error and semi-diameter d. dip and index error Ref: ¶ 20, 26

  9. 8. Which of the following corrections are applied to apparent altitude for a sun sight? a. main correction only b. main correction plus semi-diameter correction c main correction plus additional correction d. main correction, additional correction, and HP Ref: ¶ 21, 27

  10. 9. Two JN students take sights on the sun at approximately the same time from approximately the same location at sea. Mary has a HE of 8 feet and an IC of + 1.0'. Jane has a HE of 22 feet and an IC of -2.1'. Assuming both are accurate sights, which of the following is true? a. Jane's sight will have a larger ha than Mary's sight. b. Mary's sight will have a larger ha than Jane's sight. c. Jane's sight will have an hs smaller than Mary's sight. d. The ha for both sights will be about the same. Ref: ¶ 5, 20 - 21

  11. Altitude Corrections End of Homework Q & A Junior Navigation Chapter 4

More Related