# NavList:

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

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Re: Lunerian Apprenticeship
From: David C
Date: 2017 Jan 7, 16:54 -0800

I  glanced through the page and thought that I understood the basics. Then I realised that there was a gap in my understanding.

• Observe Moon and other body and calculate LD by cos formula.
• Measure LD.
• Observe  Moon and other body and calculate LD by cos formula.
• Determine time of observed LD by interpolation.

I think that my understanding has improved:

• Calculate Lunar Distance  A  by cos formula. Select a time that is consistant with local apparant time and DR position.
• Calculate Lunar Distance  B  by cos formula. Select a time that is consistant with LAT and DR position. A and B times should bracket asumed LD observation time. LD A and LD B can be pre-computed.
• Observe the moon's altitude to determine corrections to be applied when clearing the LD. Accuracy of altitude to nearest ????? Observe as close to measured LD time as possible. Is time of this observation needed????
• Observe altitude of other body (eg the sun)  to determine corrections to be applied when clearing the distance. Accuracy to nearest ????. How close in time to LD observation??  Is time of this observation needed???
• Measure LD. This measurement must be as accurate as possible. Take your time.  Record the observation time.
• Clear the distance.
• Determine time of observed LD by interpolatiing LD A  -  Observed LD  - LD B

If this is correct then in my opinion the final bullet point is the Lunar method. Everything else is detail. Unfortunately (IMHO) descriptions of the Lunar method concentrate on clearing the distance and how hard it is. It is like explaining the Mark St Hilaire method by concentrating on correcting for IE, dip, refraction and SD.

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