Principles of Celestial Navigation

A Day in the Life of a Navigator » Morning Sun Line » Sight Reduction for Morning Sun Line

strip form for the morning Sun line observation, taken a few hours after sunrise

Chief Sheedy: At time 11:46:15 GMT we took an observation of the lower-limb of the Sun. Our sextant altitude reads 35 degrees 59 minutes decimal 1. Based on our ordered course and speed of 318 true, speed of 6 knots, we extracted a DR for position at time 11:46:15. The dead reckoning position is our assumed position: 31 55 N 054 degrees 25 W. Our altitude correction for the lower limb of the Sun is +14.7. After applying all corrections, our observed altitude is 36 degrees 10.3. Our computed altitude from the Naval Observatory website is 36 degrees 25 decimal 6. The azimuth is 86.1 degrees. We are now ready to plot our Sun line.