# NavList:

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

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Re: Scale of Intercept
From: John D. Howard
Date: 2020 Feb 1, 09:55 -0800

David,

You have it wrong.  It is much simpler than that -  the intercept is 1 MOA = 1 NM.  Any direction, and azimuth.

The intercept is an angle, but an angle along a great circle.  Rember any visual sight is along a great circle.   No matter if the sun is West or the star is North-East, the angle measured is one minute of arc = one nautical mile.

You use the intercept to draw the line of position.  You do not need to figure any dLong because you can be at any longitude along the LOP.  You draw the LOP so many miles from your AP perpendicular to the azimuth.  The only time you need to figure lat and long is when you get a fix.  The fix is a point that has a lat and long but that point is also so many NM from where you are standing.  When people say they got a fix so many miles from their GPS position they are measuring point to point, not an intercept.

John H.  41N  100W

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