NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Direct Sight Reduction
From: Charles P Cohen
Date: 1996 Aug 23, 21:52 EDT
From: Charles P Cohen
Date: 1996 Aug 23, 21:52 EDT
>They claim that you can get an accurate fix from two sun
>sights taken 5 minutes apart. Ocean Navigator's tests confirmed that
>claim. Applying the method to stars, you would enter two star sights
>taken a few minutes apart and get out your lat/lon at the time of the
>second sight, without any need to adjust for the difference in time
>between the two sights.
I can believe the two-star-sight fix. Alfonso Gonzalez had a Lotus 1-2-3
spreadsheet which would do a "direct" (iterative) solution without plotting.
Two sights on the sun, 5 minutes apart, gives you two circles of position
which intersect at a _very_ acute angle. Small errors of observed altitude
result in _large_ errors of position in the direction at right angles to the
sun.
It's worth the price of the magazine to find out how they worked-around that
problem. Thanks for the note.
Charles P. Cohen <cpcohen@XXX.XXX>
Cyborg Consultants
Toronto, ON, Canada
------------------------------------------------------------------------
This mail list is managed by the majordomo program.
To from this list, send the following message
to majordomo@XXX.XXX: navigation
For help, send the following message to majordomo@XXX.XXX: help
Do NOT send administrative requests to navigation@XXX.XXX -ben
------------------------------------------------------------------------
