NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Longitude by Sunset
From: Alexandre Eremenko
Date: 2012 May 7, 12:27 -0400
From: Alexandre Eremenko
Date: 2012 May 7, 12:27 -0400
What will your Palm Pilot show for refraction if you enter altitude=0 ? Alex On Mon, 7 May 2012, Greg Rudzinski wrote: > > Alex, > > -26.4' is what my Palm Pilot Software used for refraction. The Henning Umland online sight reduction produces the same intercept value if 50 F is entered for temperature. At a temperature of 70 F then the intercept increases to 1.1' (see attachments). The ocean temperature here is 60 F and the air temperature was 70 F at the time of the observation. Lots of strange mixing goes on at the surface of the ocean so inconsistencies should be expected. > > Greg Rudzinski > > > [NavList] Re: Longitude by Sunset > From: Alexandre Eremenko > Date: 7 May 2012 10:01 > Greg, > What value of refraction did you use > for the Sun upper limb at sunset ? > And where did you take it from? > > Alex. > > On Sun, 6 May 2012, Greg Rudzinski wrote: > >> >> Grabbed a few snaps of todays sunset and low level fog and haze obscures > limb tangency with the horizon. I was able to get a LOP from an image that > has the upper limb 39.8' above the horizon using my pixel counting and > minutes of arc per pixel method. The intercept was 1.0' T with azimuth > 290.7*. This is a good result considering that the Sun is so squashed. (200mm > lens) >> >> Greg Rudzinski >> > > > > ---------------------------------------------------------------- > NavList message boards and member settings: www.fer3.com/NavList > Members may optionally receive posts by email. > To cancel email delivery, send a message to NoMail[at]fer3.com > ---------------------------------------------------------------- > > > > Attached File: http://fer3.com/arc/img/119444.picture-113.png > > Attached File: http://fer3.com/arc/img/119444.f1-picture-137.png > > > : http://fer3.com/arc/m2.aspx?i=119444 > > >