NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Multiple LOP using one sun sight
From: Peter Fogg
Date: 2005 Aug 23, 20:37 +1000
From: Peter Fogg
Date: 2005 Aug 23, 20:37 +1000
> From T. Shanklin > This method provides me > with two different azimuths from two different ded. reckoned positions, > thus > two different L.O.P.s. One celestial body at any one time can have only one azimuth. How different are these two of yours from the one sight? Using 2 azimuths that are almost parallel has the potential to lead to great inaccuracy, or to put that another way: any small change in either azimuth leads to a great change in their intersection. > Of course the accuracy of the fix depends entirely > on the one sun sight, so I usually graph/average out multiple sights for > greatest accuracy. It worked fairly well for me. Is this an acceptable > method in a pinch? Anybody else do this? On this list fairly recently was discussed finding both latitude and longitude from a series of sun sights over noon. You might like to take a cruise through the archives. Some subjects, like this one, come up regularly. > Also, I've been trying to practice with the 2102-D starfinder lately- > I've > been having a real hard time having the calculated azimuths (as per 2102) > correspond with the actual azimuth. Maybe it's just my compass, but I > always seem to be fairly far off (up to 20 degrees), even when I have the > correct star. I have been adjusting for local declination (true N to > magnetic N). Any tips? Sure you're not adding instead of taking away, or vice-versa, your magnetic variation? 20 degrees is a lot of deviation, or local error, but the presence of magnets (eg, sound speakers) in the vicinity can do this. Someone I know had a similar problem that was solved by removing the knife in its sheath from the pillar holding the cockpit compass.