NavList:

How to get that accurate celestial fix. Some of the rules in piloting line of position applied to celestial line of position. One example is if stars are within 180° of each other you may be outside of the fix triangle. Another, if they star are 180°apart such as North and South you may be between the separated lines. This often tell the story, (draw arrows in the direction of each body on the line of position) if all lines (LOP’S) are moved equals distance in the direction of the Arrow or in the opposite direction and a tight fix appears, it may be a personal correction that needs to be applied for that person. With systematic error and little random error we should end up with a near pinpoint fix.(It may also help with refraction or DIP correction of the eye,or other systematic error.) The amount of adjustment necessary with the north-south east-west may be obvious. . So the north-south east-west star fix can be an education tool as well as just a fix. My story of the vertical sextant leads to another thought, smaller vessels such as the submarine where you are close to the water and needed a fix well after sunset, you needed to adapt your eyes to low-level of light. Using red light at least 20 minutes before gone on deck and having someone back to back with a red flashlight not shining in your eyes (or need for you to write)for the mark while taken the Sextant shot and using the off sight rods/cones in eyes (not looking directly at the horizon) when looking near the horizon. Even closing your eyes for a few minutes. And then opening for the shot gives benefit to night vision. Polaris the second magnitude star needs more darkness so the horizon may not be at its best. I was involved in the days work in Navigation and found that many did not have the best eyes for celestial navigation. I would pick up a star and shoot it while everyone was saying where,where,where. I taught, and would section off the sky and first shoot away from the sun and high, working down lower and toward the sun. This gave me early sights with a good horizon. . There are tricks to better you sight. Let’s hear some.
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