NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Newbie Question - Parallel LOPs
From: Mark Waters
Date: 2009 Feb 8, 23:10 -0800
From: Mark Waters
Date: 2009 Feb 8, 23:10 -0800
Thanks everyone for the responses. My mistake was - a so many were quick to point out - in my Zn calculations. I had neglected to add 360 degrees to my GHA and thus arrive at a figure where Zn = Z. With an incorrect LHA I used Zn = 360 - Z. With corrections made the fixes were good to within a couple of miles. Making mistakes sure helps reinforce the lessons! Now to start practicing with stars. On Feb 6, 3:51�pm, m_bur...@MSN.COM wrote: > Hi Mark, welcome to List. Unless I missed something would you be so > kind as to supply the data for sight reduction? Thanks much! > Mike Burkes > 626-833-1521 > > On Jan 28, 12:08�am, Watermarkwrote: > > > > > I've recently taught myself Celestial Navigation from library books > > but I still have some newbie questions. I thought I was doing fairly > > well using an artificial horizon - accuracy to within 6NM last week - > > but today after taking sun sights at 10.00 and 14.00 all my LOPs ran > > parallel. I reduced 8 different sights and double checked everything > > but the same result. I had read that a 4 hour spread would be enough > > but today my LHAs and Zn's all came out similar. My DR Long is 121W. I > > can only deduce that taking sights of the sun at a similar altitude at > > 10.00 and 14.00 caused the LHA to be too close despite 4 hours time > > difference? Is this correct and will this always occur taking sights > > at this time if not moving? Excuse the naivety but like I said I am > > still a beginner. > > Many thanks, > > Mark- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---