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From: Alexandre Eremenko (no email)
Date: Sat May 28 2005 - 10:13:59 EDT
Fred,
Sorry. I made a typo as always:-(
This time in the date of the second observation:
the correct date is May 28, that is this morning.
(I computer the altitudes two times before posting them:-)
> First, I think it's great that Alex is getting
> observations that are
> within 0.1' or 0.2' of arc from his known position,
Why do you say "within 0.1' or 0.2' ?"
The error is less than 0.1', but with the typo uncorrected it is
6.6' as you say:-))
> One would think that adjusting the backlash
> on the sextant wouldn't
> have affected the readings as long as one always
> approached the final
> setting from the same direction.
As I said, I am not sure what they adjusted, though I saw
the whole procedure, because
we could not properly communicate.
> One psychological explanation may be that Alex finally became
> confident enough in his instrument and himself
This cannot be an explanation.
I have no doubt that my sextant had some strange bias
always in the same direction, of variable magnitude
and range about 0.3'-0,6'.
You used it yourself once with the result +0.3' off with
art horizon (which is really equivalent to +0.6'.
I understand that your single measurement proves nothing
but I have two large notebooks full of observations
taken in October-May.
Something WAS wrong with this sextant though I don't
know exactly what it was.
Second observation with corrected typo:
> > May 28, Sun LL art horizon (plate of sunflower oil), watch -1 sec.
> > IC=+0.6. Same place.
> > GMT by watch: Sextant reading:
> > 6:15:07 51d01.3'
> > 6:17:16 51d39.3'
> > 6:18:30 52d00.8'
> > 6:21:00 52d44.0'
> > Averages: 6:17:58 51d51.35'
> > Corrected:6:17:57 51d52'
> > Divided by 2 and LL corr: 26d10' (corrected observed alt)
> > Computed alt (by hand w Casio): 26d09.96'. Error: 0.0'
A.
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