[Aavso-photometry] Errors on AIP

[Michael Koppelman]

OK, hopefully the last update to this. This is a spreadsheet to 
calculate uncertainties from the text output from AIP 
(http://www.willbell.com/aip/index.htm).

I've updated it to use the S/N equation from "Handbook of CCD 
Astronomy" by Steve B. Howell. The equations aren't numbered in that 
book but it is on the bottom of page 55. It takes into account the gain 
and readnoise of the CCD as well as the noise from the star itself and 
the sky. It has a term for "dark current" which I don't use because I 
don't understand why it is there since we all subtract that out of our 
data frames.

The spreadsheet is here:

http://www.lolife.com/astronomy/AIP_Err.xls

I welcome any comments or feedback.

Cheers,
Michael Koppelman
http://www.lolife.com/astronomy/