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Subject: Fwd: Re: Sextant accuracy with short distance to horizon
From: Dale Tilson (d.tilson@XXX.XXX)
Date: Tue Jun 26 2001 - 15:49:36 EDT
Re: the Aussie using his fence for a horizon, several people wrote:
> >> That's interesting. But surely one must make an allowance for the fact
> >> that the fence is not at the same altitude as the horizon.
> >
> >I can't remember that much about the post, but I THINK he had some kind
> of HE
> >correction for his eye above the fence line.
> >
>He would need extremely accurate survey data if there was
>any meaning to be had. He would have to know the relative
>height of the fence and his eye, as well as the distance to
>the fence.
OK, guys, I'm new at this so somebody help me out.
I thought the "dip" correction was necessary because the horizon isn't
level with your height of eye. Aren't we actually trying to measure
altitude above a line horizontal with the line-of-sight? If so, our Aussie
friend would only need to find a perch so that his eye was level with the
fenceline.
If not, somebody straighten me out quick, because I was gonna set up an
observation post in the back yard based on that premise.
Thanks,
Dale
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