NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Observations with pocket sextant in the Baltic
From: Alexandre Eremenko
Date: 2006 Jul 13, 05:36 -0500
Bill,
> These are a combination of the LARGEST on and off
> figures in each set, not an average or pairing.
> The average is almost
> always below the 4SD figure by 0.2' or more.
Sorry, but I still don't understand your concern.
Within 0.2' of the correct 4SD is perfect.
(The measurement is good if you are within 0.4'
of tabulated 2SD).
The expression "0.2' or more" I just do not understand.
How much more?
I understand when you say that your numbers seem biased
to one side. But if the bias in the 4SD is 0.2'
there is no reason of concern.
If the bias is 0.6' there are some reasons.
If the bias is at most 0.4' in 80 % of all observations,
it is still OK on my opinion.
Or let me put it in another way: how many observations you
have to reject by the "0.4 test"? More than 1/2 or less than 1/2?
Alex.
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From: Alexandre Eremenko
Date: 2006 Jul 13, 05:36 -0500
Bill,
> These are a combination of the LARGEST on and off
> figures in each set, not an average or pairing.
> The average is almost
> always below the 4SD figure by 0.2' or more.
Sorry, but I still don't understand your concern.
Within 0.2' of the correct 4SD is perfect.
(The measurement is good if you are within 0.4'
of tabulated 2SD).
The expression "0.2' or more" I just do not understand.
How much more?
I understand when you say that your numbers seem biased
to one side. But if the bias in the 4SD is 0.2'
there is no reason of concern.
If the bias is 0.6' there are some reasons.
If the bias is at most 0.4' in 80 % of all observations,
it is still OK on my opinion.
Or let me put it in another way: how many observations you
have to reject by the "0.4 test"? More than 1/2 or less than 1/2?
Alex.
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---
