Principles of Celestial Navigation


Introduction » Lesson Objectives

This training will introduce navigators to the fundamentals of the celestial navigation. After completing the course, the navigator will be able to:

  1. Name the coordinates that define a location on Earth, a location on the sky, and a location as viewed from the rotating Earth.
  2. Define "geographic position" with respect to the position of a celestial object.
  3. Define zenith and zenith distance.
  4. Describe how one measures zenith distance.
  5. Describe the relationship between zenith distance and geographic position.
  6. Define lines of position (LOPs), and what intersecting LOPs determine.
  7. List the steps that a navigator performs as he/she plots lines of position; describe how to plot LOPs on a chart.
  8. Summarize the accuracy of positions determined using celestial navigation.
  9. List some advantages and limitations of celestial navigation.
  10. List the information required to obtain a celestial navigation fix.
  11. List the instruments required to make an observation.
  12. List the necessary corrections to a sextant measurement, also known as sextant altitude or Hs, to produce an observed altitude or Ho.
  13. Describe the Intercept Method.
  14. Describe why an "assumed position" is used.
  15. Describe how to calculate the intercept distance using Ho and Hc.
  16. Describe how the intercept distance, azimuth, and the moniker HoMoTo are used to plot a LOP.
  17. Describe the special publications used to determine Hc and Zn of an object.
  18. Describe the contents of The Nautical Almanac and Pub 249, and how they are used in sight planning.
  19. List the different navigational sights taken during a 24-hour period on a naval passage.
  20. Define the concept of a running fix and explain how to plot it.
  21. Describe how mid-morning and mid-afternoon Sun sights can constrain a running fix.
  22. Summarize the concept of a Local Apparent Noon Sun sight, and how it can yield a fix.