NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Instumental error?
From: Frank Reed
Date: 2005 Apr 20, 23:23 EDT
From: Frank Reed
Date: 2005 Apr 20, 23:23 EDT
Bill wrote:
"> If I recall, the specs
> are plus/minus 10 seconds error along the arc (0.17').
> Unless you got a
> dud, any value higher than 0.2' is highly suspect.
> are plus/minus 10 seconds error along the arc (0.17').
> Unless you got a
> dud, any value higher than 0.2' is highly suspect.
And Alex replied:
"Yes, I'm afraid it is a dud."
"Yes, I'm afraid it is a dud."
I don't buy it. That the certificate *says* the error is 10 seconds doesn't
mean much of anything. Arc error is a correctable error and shooting
lunars/star-star sights is probably the best way to detect it. Build your table,
and then use it. And the fact that such error exists doesn't mean the instrument
is a "dud". Correcting for arc error, once you have determined it, is every bit
as easy as correcting for index error.
-FER
http://www.HistoricalAtlas.com/lunars
http://www.HistoricalAtlas.com/lunars