NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Beginner
From: Willem Piccer
Date: 2005 Sep 11, 18:54 +0200
From: Willem Piccer
Date: 2005 Sep 11, 18:54 +0200
I have a Norie's Nautical tables from 1964 which gives a position for Trondheim of 63 27 N 09 44 E Compare this with what Asbjorn gave us: 63 25,4 N 10 24.7 E May-be Asbjorn took his GPS position from a list as did both Geoffrey Kolbe and George Huxtable. The point I want to make clear is that this mystery about Asbjorn's big discrepancy might be explained from a mistake in the starting position. Thanks George for your warm welcome; I will try to contribute to the dicussions whenever possible Willem Piccer ----- Original Message ----- From: "george huxtable"To: Sent: Sunday, September 11, 2005 12:04 AM Subject: Re: Beginner > Geoffrey Kolbe wrote- > > >At 18:13 10/09/2005, Willem Piccer wrote: > > > >>I was just re-reading the discussion on the problems Asbjorn had and I > >>wonder if the whole problem is not caused by the gps position used. > >>Especially because he states that the observation height is always less > >>than the calculated height. > >>I have the feeling that the chart datum chosen plays a role > >> > >>Willem Piccer > > > > > >The latitude and longitude which Asbjorn's GPS deduces for Trondheim (where > >Asbjorn says he took the sights) agree with that given in various atlas's > >and gazetteers that I have to less than a minute. A glance at the atlas > >shows that a position five miles North and East of Trondheim (where Asbjorn > >would have to be to get an observed altitude 5 minutes less than > >calculated) would put him in Trondheims Fjord....! > > > >Asbjorn would appear to be where he thinks he is. > > Response from George- > > Not necessarily so. He would not have to be at the place that Geoffrey has > specified, to get an observed altitude 5 minutes less than calculated. > Anywhere on a position line passing through that point, and perpendicular > to the Sun's azimuth, would fit his observation. So he would not have to be > in Trondheim's Fjord. Still, it would be useful if Asbjorn would confirm > (or not) whether that GPS position corresponds well to his place of > observation. > > There remains something of a mystery about Asbjorn's big discrepancy, in > what should be a very accurate observation. Perhaps he will repeat his > measurement, next time the Sun shines in Trondheim, and before it gets too > low to observe well from his Northerly latitude. > > And I would like to welcome Willem Piccer's first contribution to this > list, from Zeeland, Holland. > > George. > > > =============================================================== > Contact George at george@huxtable.u-net.com ,or by phone +44 1865 820222, > or from within UK 01865 820222. > Or by post- George Huxtable, 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 > 5HX, UK. >