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Re: Lunar trouble, need help
From: Kent Nordstr�m
Date: 2008 Jul 9, 15:15 +0200
From: Kent Nordstr�m
Date: 2008 Jul 9, 15:15 +0200
Kent wrote [5606]: "Being a professional navigator myself (long time ago) I would say that the > moon should be avoided for finding the MT and longitude due to its > un-regular movements. Only if no other means are available the moon shall > be > used, then preferably in or close to the prime meridian." The confusion, if any, is caused by my bad words. It shall of course be "the prime verical" and not the "prime meridian". Kent N ----- Original Message ----- From: "George Huxtable"To: Sent: Wednesday, July 09, 2008 8:47 AM Subject: [NavList 5757] Re: Lunar trouble, need help > > Jim Wilson wrote- > > | Your statement that the closer the observed body is to the prime > meridian > | (due East or West), the better it will be. I thought that the prime > | meridian went through Greenwich, and that the prime vertical was due > east > | or west. Was I taught wrong? > > You were taught right: I said it wrong. Sorry. > > Indeed, it was a double slip, because I was commenting on a statement by > Kent Nordstrom, back in [5606], which ended- > > "Being a professional navigator myself (long time ago) I would say that > the > moon should be avoided for finding the MT and longitude due to its > un-regular movements. Only if no other means are available the moon shall > be > used, then preferably in or close to the prime meridian." > > and somehow took his words to mean "close to due East or West"; which they > didn't. If I had realised that, I would have questioned that statement, > and > not written > "I fully agree that for determining time or longitude, the closer the > observed body is to the prime meridian (due East or West), the better it > will be" as I did. > > So, to try to clarify the matter: for the purpose of determining time or > longitude, an observation of Moon altitude is as good as that of any other > body, if it's corrected with care. However, the closer an observation of > any > body is to the prime vertical (due East or West), the better it will be > for > that purpose. > > Thanks to Jim for pointing it out, and providing a chance to clear it up. > > George. > > contact George Huxtable at george@huxtable.u-net.com > or at +44 1865 820222 (from UK, 01865 820222) > or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. > > > > > --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---