Quote:
Originally Posted by rogerg
I think I have the answer ... weighted-sum in CCDStack, which might or might not be different to PixInsight's method Rick has mentioned  |
Yes, it is different. PixInsight's image normalization for combination does roughly the same thing as CCDStack's normalization - it attempts to deal with differences in mean background level and dispersion between subs. The noise estimation and consequent weighting done by PI is a separate function that doesn't appear to be done by CCDStack.
You may still get quite reasonable results just from "simple" normalization.
I like to squeeze the last drop of SNR out of my data so I tweak the algorithms and parameters and look at the SNR numbers as well as the rejection maps and the integration result. That probably comes from being a mildly OCD computer geek who is trapped in management
Cheers,
Rick.