Celestial Navigation · Running Fix — Celestial
Two sun lines are taken three hours apart (e.g., a morning sun line and the LAN latitude). To combine them into a running fix you must:
- APlot both from the same assumed position without advancing
- BAverage the two latitudes
- CDiscard the earlier line and use only the noon latitude
- DAdvance the earlier LOP along the course and distance run between the observations, then cross it with the later LOP✓ Correct
Explanation
A single body gives only one LOP at a time. The classic sun-run-sun running fix advances the morning sun line for the run to the time of the second observation (often the noon latitude line) and crosses them for a fix.
Authority: Bowditch (Pub. No. 9), running fix; the day's work
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