Signal-to-noise calculator for CCD photometry at WIYN 0.9m

Michael Richmond
Aug 13, 2013
Dec 28, 2016

This form allows you to calculate the signal-to-noise ratio for a star observed with the WIYN 0.9-m telescope. You can vary the parameters and find out what sort of results to expect.


If you want to see the calculations themselves, try reading the Perl source code to the calculator. Or, if you just want to see the equations governing the calculations, try this article by Steve Howell.


Filter: This calculator uses Bessell filters, which are close to Johnson UBV, Cousins RI.
Mag Limits: List values for magnitudes between: and at intervals of mag.
Moon phase: (days: 0 = new, 14 = full)
Exposure time: (seconds)
FWHM: (arcsec)
Radius for photometry: area over which signal is measured (arcsec):

You may have to wait 10-20 seconds for result.

Last updated Dec 28, 2016 by Michael Richmond.