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 ------------------------------------------------------------------------