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Fred,
thanks.
Just looked at their web page: $940 !
0.5' sensitivity. It really makes sense to
make one oneself:-)
Alex.

On Sun, 20 Feb 2005, Fred Hebard wrote:

> Freiberger makes one.  People also have made their own.  There are some
> threads about this in the archives over the past two-three years.
> Bruce Stark wrote that leveling one he built himself to high accuracy
> takes a fair amount of time.
>
> On Feb 20, 2005, at 1:24 PM, Alexandre Eremenko wrote:
>
> > Dear George,
> > Thank you for your interesting info
> > on art horizons.
> >
> >> That's why the other (Norwegian?) type of artificial horizon,
> >
> > I've seen pictures of them in the books only.
> > Are they still available?
> > Theoretically, it seems to me that this model should be preferred
> > for land observations.
> >
> > With my liquid art horizon I had a funny accident when I tried
> > to use it first. Once I took a series of Sun altitudes
> > which looked very good (very little scattering in the series)
> > but when reduced showed a systematic error of about 2 degrees.
> >
> > It took me a while to figure out what was going on:-)
> > My art horizon stands on an iron table with glass top.
> > I confised the Sun reflection from this glass top
> > with reflection from the art horizon:-)
> >
> > Then an idea came to fix a good optical quality mirror
> > permanently in horizontal position,
> > and use it as an artificial horizon. I am sure that there
> > are bubble levels of sufficient precision to do this:
> > they use such levels in transit instruments, don't they?
> >
> > So it seems that a mirror-type art horizon would be much
> > more convenient for land observations.
> > Are they still produced?
> >
> > Alex.
> >
>

   

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