NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: 3 fix celestial problems
From: Millard Kirk
Date: 1997 Sep 03, 9:29 PM
From: Millard Kirk
Date: 1997 Sep 03, 9:29 PM
Russell Sher wrote: > > Hi - I am intrigued by the 3 fix celestial problems where the DR is not given (to make things interesting) and the observer could be anywhere on the terrestial sphere - I would like to ask the following: > > 1. What does one use for the initial DR guess? (you have to start somewhere !) - does one just guess and then recalculate once the (huge) intercept is obtained so as to make the intercept zero (by moving along the intercept) and then use the newly obtained DR as the DR for the remaining sights? > 2. Has anyone plotted large intercepts on a large enough scale plotting sheet and obtained the fix this way? without recalculating > 3. Is there a better method than just guessing initially? > 4. I would be interested if anyone would like to discuss their method of reducing these sights > ALSO - check out: http://users.aol.com/promarsoft/navsite/map.htm > for the beta version of skymate software > Cheers > Russell Dave Weilacher <0002125481@mcimail.com> Ask that three sun sights be posted so that those interested could try and find the position.. I posted three sun sights and one moon sight. I did not give the DR or ZN but did indicated if the DR was needed it could be found by using my address in the signature of the post. Whether or not the position could be found without a DR I do not know and also would be interested in knowing. A couple of questions comes to mind: If one knew the ZN could they find the position without a DR, and if one was place somewhere in the middle of a ocean not knowing their DR could they find where they were by shooting three stars, sun, moon or planets. Using computers, calculators, ets.. No GPS or LORANS Please. Note: LiebermanMillard,I think you are at 38d 24.3'N, 82d 17.9'W (a long way from the> briney blue!) Well that is about as close as I get when I calculate the sight. Well... maybe a little closer. Lieberman results are closer to the GP than what I calculate. Good job Lieberman. Original sights plus ZN and DR 38d N 82d W Sun Sun Sun Moon GMT(Date) 8 Oct 1996 14 Oct 1996 29 Oct 1996 25 Oct 1996 GMT 18:54:33 16:39:44 14:58:58 02:11:21 Hs (LL) 39d 41.1' 42d 12.1' 28d 59.1' 47d 03.2' IC 0 0 0 0 Dip 0 0 0 0 ZN 213 168 142 137 All shots where taken using the ASTRA IIIB and an artificial horizon. No IC and no Dip. The lower limb of the bodies where used. From my address below you should get an assumed position or DR. The house is not moving now, well it used to move a lot before got proficient with the sextant. Learning the Hard Way!! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Millard Kirk KB8YQO Email - mkirk@marshall.edu 116 Lewis Ave Homepage- http://webpages.marshall.edu/~mkirk/ Barboursville, WV A West Virginia Blue Water Sailor 25504 (304) 736-6544 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-= =-= TO UNSUBSCRIBE, send this message to majordomo@ronin.com: =-= =-= navigation =-= =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-=