At 0100 zone time on 23 September your DR position is LAT 24°25.0'N, LONG 83°00.0'W. You are steering course 315°T. The speed over the ground is 10.0 knots. You observed 3 morning sun lines. Determine the latitude and longitude of your 1100 running fix. ZONE OBSERVED TIME GHA ALTITUDE(Ho) DECLINATION ---- --- ------------ ----------- 0700 17°20.1' 21°09.0' S 00°09.7' 0900 47°03.0' 46°05.0' S 00°11.6' 1100 77°06.4' 63°16.1' S 00°13.5'
• Running fix with sun lines using earlier LOPs (lines of position) advanced to the time of the last sight • Relationship between course, speed, and DR track from 0100 to each sight time • How longitude changes when traveling northwest (course 315°T) in the Western Hemisphere
• From the 0100 DR, determine your DR positions at 0700, 0900, and 1100 based on course 315°T and 10 knots. How far along track have you moved by each time? • Think about the pattern of the three sun lines: are they likely to shift your running fix more north/south or more east/west compared to the DR at 1100? • Compare each answer choice to the 1100 DR position you would have without any sights. Which options are inconsistent with the distance and direction run from 0100 to 1100?
• Compute the total distance run from 0100 to 1100 at 10 knots and confirm it matches the change in position from the initial DR to each answer choice • Check whether the change in latitude from 24°25.0'N to each option is reasonable for the track and distance traveled • Check whether the change in longitude (becoming more westerly) matches what you’d expect when steering 315°T in that region and distance run
No comments yet
Be the first to share your thoughts!