Next message: Alexandre Eremenko: "Re: Testing SNO after fixing"
On May 28, 2005, at 5:27 PM, Alexandre Eremenko wrote:
> Fred,
> You wrote:
>
>> By my calculations with your two sets of sights, the mean and
>> standard deviation of Ho-Hc in minutes of arc were 0.096 +/- 0.195
>> and 0.032 +/- 0.137. Were your previous sights this precise?
>
> I did not reduce each sight. Only the averages.
> My previous obsrvations with art horizon were generally less
> precise. And many of them showed systematic error (overshot).
> Same happened with star distances, with a larger error.
>
> What does the second number (after +/-) in your message mean?
> Maximal deviation from the average or standard deviation?
> (I suppose the first number is the average Ho-Hc).
The second number is the standard deviation of Ho-Hc and the first
number is the average or mean of Ho-Hc. In print, the mean and
standard deviation usually are separated by a plus sign (+) directly
over the minus sign (-). Since that's not possible in the 128-bit
ascii of email, I used "+/-" as a substitute.
Did the master at Freiberg clean the arc and worm on your sextant?
Bill just posted about an effect of a dirty arc on accuracy.
Fred
