NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Meridional Distances
From: Michael Wescott
Date: 2002 Sep 17, 22:15 -0400
From: Michael Wescott
Date: 2002 Sep 17, 22:15 -0400
> 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@EMC.COM
