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Re: Meridional Distances


Subject: Re: Meridional Distances
From: Michael Wescott (wescott_mike@XXX.XXX)
Date: Tue Sep 17 2002 - 22:15:08 EDT


> I'm glad Dan thinks the Williams formula is pretty straightforward.
>
> My new (again, new to me) formula for rhumb line goes
>
> Arctan course = DLON/DMP
>
> Distance = DMD/cosCourse
>
> where:
> DLON means the difference in longitude expressed in minutes of arc
> DMP means the difference in Meridional Parts
> DMD means the difference in Meridional Distances

Looks like this is a variation on meridional parts that takes into
account the varying relationship between a minute of latitude and
a nautical mile as a function of latitude. The traditional method makes
the assumption that a minute is a mile no matter where you are on the
earth's surface.

--
        Mike Wescott
        Wescott_Mike@XXX.XXX





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