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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: George's test
From: Fred Hebard
Date: 2004 Nov 13, 19:27 -0500
From: Fred Hebard
Date: 2004 Nov 13, 19:27 -0500
On Nov 13, 2004, at 6:24 PM, Alexandre Eremenko wrote: >> Measuring the sun's semidiameter with the sextant in various >> orientations does seem to be good practice for taking lunars. > > Taking lunars themselves, as well as star-to-star distances > whold be even better practice. My purpose here was > to check the rigidity of my sextant. I agree, but I take many more semidiameter measurements than lunars or star-to-star measurements, since I use them for index error determination in conjunction with altitude shots of the sun, so why not vary the orientation? >> By the way, I get numbers similar to your right >> side up measurements on >> dry land, > > With what sextant and scope? > With either a Husun Mate or a C+P, the Husun with a 2.5x31 star scope and the C+P with a 4x40 scope. Here are some samples, the Husun in minutes and seconds, the C+P in minutes with tenths of minutes. Husun: 04/27/2003 10:50 33 35 30 5 04/27/2003 10:50 33 45 29 55 04/27/2003 10:50 33 45 29 55 04/27/2003 17:50 33 35 30 15 04/27/2003 17:50 33 45 30 20 04/27/2003 17:50 33 50 30 15 05/10/2003 18:30 33 35 30 10 05/10/2003 18:30 33 15 30 20 05/10/2003 18:30 33 20 30 20 05/11/2003 17:05 36 45 26 15 05/11/2003 17:05 36 55 26 15 05/11/2003 17:05 37 10 26 20 C+P: 09/11/2004 16:40 32.1 31.8 09/11/2004 16:40 31.9 31.8 09/11/2004 16:40 32.0 31.9 09/19/2004 17:45 31.8 32.0 09/19/2004 17:45 31.7 32.1 09/19/2004 17:45 31.7 32.0 09/20/2004 18:15 31.2 32.6 09/20/2004 18:15 31.4 32.4 09/20/2004 18:15 31.3 32.3 09/21/2004 17:00 31.5 32.4 09/21/2004 17:00 31.7 32.4 09/21/2004 17:00 31.8 32.2 09/22/2004 14:00 32.1 31.9 09/22/2004 14:00 32.0 31.9 09/22/2004 14:00 32.3 31.9 Fred