# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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Time sight vs Oops I forgot to wind the chronometer.
Date: 2015 Nov 11, 17:53 -0800

In "Self Contained Celestial NavigationWith HO 208"  I noticed another iteritive method.

Basically he postualtes if you are in a known position, and your chronometer stops, you can regain GMT.

Method:

Estimate GMT

Take a sight and solve for an LOP using estimated time.  Use an assumed positon for a rational distance intercept if your time is a bit off.

Plot the LOP that was created by your guesstimate sight. Compare to known position.

Use longitude difference to correct time.  Adjust time, and recalculate the LOP with corrected inputs. Make any final tweaks with new LOP..

OK..I get it...I just question this vs the LHA angle solution using spherical Law of cosines, or the old Bowditch approach with halfsum and polar distance.

If I know my current positon.

Take a sight, solve for LHA.

Correct for Equation of time and Get Local mean time.

If you know your longitude...re-establish GMT from LMT

I would think you can't get in too much trouble unless you really miss your time badly.  Declination changes slowly enough to forgive a few hours without great pain. Use a star other than mother sun how can you go wrong.

Am I being dimwitted and missing the obvious here, or is the first just different strokes for different folks?

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