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Subject: Relative Importance of Accurate Timing of Sight for Lunars versus Altitude Sights
From: Fred Hebard (Fred@XXX.XXX)
Date: Mon Jun 09 2003 - 22:48:28 EDT
It has taken me a long time to where I can consistently get my altitude
sights to under 0.5' of arc from a known position on dry land, often,
now, under 0.2' of arc. A critical component of that has been judging
the exact moment of contact and hitting the stop watch accurately at
that moment. After setting the angle, I generally wait for the object
to converge with the horizon, or itself in the artificial horizon, and
try to hit the stop watch when contact occurs.
However, I always had a fair amount of luck with lunars, even before
improving my timing technique for altitude sights. That was back when
I would look down at my watch after perfecting the contact and record
the time.
I still prefer this second method for lunars and believe it is the best
for that observation. That is because 12 seconds of time elapse, more
or less, between each shift of 0.1' of arc in a lunar. It doesn't make
much difference whether you're 2-4 seconds out. It's much more
important to get the angle measured to the utmost precision possible
than to time the sight accurately. You need to concentrate much more
on proper manipulation of the micrometer than on the time, like when
checking index error by determining the semi-diameter of the sun.
Any comments?
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