Next message: Fred Hebard: "Re: Russian trick"
On Oct 4, 2004, at 1:05 AM, Alexandre Eremenko wrote:
> After many repeated measurements I found the star-to-itself
> method more precise than the Sun method. This is the case
> with my sextant, my scopes and my specific observation
> conditions, I do not generalize this to all situations.
> (Unfortunately I have no possibility to use real
> horizon at this time).
>
> I can post the numerical data if this is interesting.
>
> However I don't know of any other method (other than star-to-star
> distances) of measuring what you call "centering error"
> without special equipment.
> This should answer your sentences:
> You say that the better method was:
>
>> At one time, an instrument
>> could be sent off for testing by a system of
>> collimators,
>
> But I don't have a collimator. And many other people don't.
> Bougainville :-) who used the stars for a similar test,
> as described in the recent messages:
Alex,
I would like to see some of your star data for index error. I post
below some sun data, with a few moon determinations.
Regarding machines for determining centering error (the centering of
the pivot of the index arm), I don't believe those are called
collimators. I believe a collimator is for determining centering of
the telescope. The machines and operators, together encompassing a
service, for determining centering error are not available in the U.S.,
to the best of my knowledge, except possibly at the Warren-Knight
Instrument Co., <http://www.warrenknight.com/WKCalibration.html>.
Fred
date&zone time object,sextant on' off' IndexError" SD'
09/05/2004 15:15 sun, C+P 32.4 31.1 39 15.88
09/05/2004 15:15 32.4 31.1 39 15.88
09/05/2004 15:15 32.4 31.2 36 15.90
09/05/2004 15:55 sun, C+P 32.3 31.5 24 15.95
09/05/2004 15:55 32.2 31.3 27 15.88
09/05/2004 15:55 32.2 31.5 21 15.93
09/06/2004 10:30 sun, C+P 31.7 31.75 -1.5 15.86
09/06/2004 10:30 31.8 31.9 -3 15.93
09/06/2004 10:30 31.8 31.9 -3 15.93
09/10/2004 19:00 sun, C+P 31.6 32.1 -15 15.93
09/10/2004 19:00 32 32 0 16.00
09/10/2004 19:00 31.8 32 -6 15.95
09/11/2004 16:40 sun, C+P 32.1 31.8 9 15.98
09/11/2004 16:40 31.9 31.8 3 15.93
09/11/2004 16:40 32 31.9 3 15.97
09/19/2004 17:45 sun, C+P 31.8 32 -6 15.95
09/19/2004 17:45 31.7 32.1 -12 15.95
09/19/2004 17:45 31.7 32 -9 15.93
09/20/2004 18:15 sun, C+P, 31.2 32.6 -42 15.95
09/20/2004 18:15 31.4 32.4 -30 15.95
09/20/2004 18:15 31.3 32.3 -30 15.90
09/21/2004 17:00 sun, C+P 31.5 32.4 -27 15.97
09/21/2004 17:00 31.7 32.4 -21 16.02
09/21/2004 17:00 31.8 32.2 -12 16.00
09/22/2004 14:00 sun, C+P 32.1 31.9 6 16.00
09/22/2004 14:00 32 31.9 3 15.97
09/22/2004 14:00 32.3 31.9 12 16.05
09/23/2004 17:30 sun, C+P, 31.8 32.6 -24 16.10
09/23/2004 17:30 32 32.4 -12 16.10
09/23/2004 17:30 32.1 32.4 -9 16.12
09/24/2004 22:30 moon, C+P 32.5 32.7 -6 16.30
09/24/2004 22:30 32.3 32.6 -9 16.23
09/24/2004 22:30 32.4 32.7 -9 16.27
09/26/2004 09:45 sun, C+P, 31.7 32.5 -24 16.05
09/26/2004 09:45 31.8 32.4 -18 16.05
09/26/2004 09:45 31.9 32.4 -15 16.07
09/29/2004 05:50 sun, C+P, 31.5 32.65 -34.5 16.04
09/29/2004 05:50 31.5 32.8 -39 16.07
09/29/2004 05:50 31.4 32.7 -39 16.02
09/29/2004 22:00 moon, C+P 30.3 31.3 -30 15.40
09/29/2004 22:00 30.2 31.6 -42 15.45
09/29/2004 22:00 30.3 31.4 -33 15.43
09/30/2004 17:20 sun, C+P 31.7 32.45 -22.5 16.04
09/30/2004 17:20 31.5 32.5 -30 16.00
09/30/2004 17:20 31.5 32.4 -27 15.97
10/01/2004 16:40 sun, C+P 31.5 32.6 -33 16.02
10/01/2004 16:40 31.6 32.4 -24 16.00
10/01/2004 16:40 31.6 32.4 -24 16.00
10/02/2004 10:00 sun, C+P 31.7 32.3 -18 16.00
10/02/2004 10:00 31.7 32.4 -21 16.02
10/03/2004 13:45 sun, C+P, 32 32 0 16.00
10/03/2004 13:45 32.1 31.7 12 15.95
10/03/2004 13:45 32 32 0 16.00
