NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Multiple LOP using one sun sight
From: T. Shanklin
Date: 2005 Aug 22, 22:35 -0700
From: T. Shanklin
Date: 2005 Aug 22, 22:35 -0700
I recently taught myself celestial navigation. In working out a sun sight I recently came up with an idea for getting a better fix using only one sun sight (although it is so simple I'm sure people do it). I calculate and plot one line of position using H.O. 229 and the whole degree Latitude and adjusted Longitude D.R. coordinates (as required by pub 229). After that I reduce the sight using the formula provided in the Nautical Almanac (sinHc=sinDec*sinLat+cosDec*cosLHA*cosLat...&c.). This method provides me with two different azimuths from two different ded. reckoned positions, thus two different L.O.P.s. 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? 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? T. Shanklin ********************** Prime numbers are what is left when you have taken all the patterns away. I think prime numbers are like life. They are very logical, but you could never work out the rules, even if you spent all your time thinking about them. _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today - it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/