Example of position fixing

C o n t e n t s

• Position fixing from the stars
• The starry sky
• The celestial sphere
• What you see at the North Pole as the Earth rotates
• How the starry sky changes when traveling to the equator
• Effect of Earth’s rotation on the starry sky at the equator
• Celestial meridian, upper and lower culmination
• Change in star altitude at the poles, equator, and between them
• Declination
• Example of determining latitude
• Hour angle, Greenwich Hour Angle (GHA)
• Aries, the celestial Greenwich
• Sidereal Hour Angle (SHA)
• Local Hour Angle (LHA)
• Relation between hour angle and time
• Example of determining longitude and latitude from the Sun at noon
• Relation between angles, degrees, and nautical miles on Earth
• Position circle
• Azimuth (A)
• True bearing to a star
• Nautical triangle
• Solving the nautical triangle (altitude calculation)
• Position fixing using Marcq Saint Hilaire intercept method
• Star identification
• Details and practice
• Time
• Time difference (ΔT)
• Altitude measurement
• Example of position fixing
• Twilight
• Calculation of twilight time
• Navigation exam