Processing question: HELP!!!!

Hello guys
a question for the most experienced:

I have a large number of 600sec st11K images. I cannot process them all at once (my pc, although powerful, cannot cope): what would be the best way to go about it?
If I process smaller groups, stack them (via averaging) and then process the resulting averages as if they were single images stacking them also via averaging, would this work as if I were processing the whole batch and average-stack them?

I have an ongoing project that I cannot complete unless I find out how to solve this problem

thanks for any advice guys

Luca

Hi Gianluca,
That will work fine. Just do so many at a time and then when you have stacked them all, stack the combined files as if they were just regular FITS.
I have done this when I had too many.

Hi Gianluca,

You might also try summing your individual subs and then averaging the stacks together.

Try both and see which you prefer!

Jason

Luca,
You didn't say what processing program that you are using, so I can't give specific advice, but here are some guidelines:
-----Your averaging method that you described will only work well if the total of each group of subexposures is equal, otherwise some groups will have a greater contribution they should and some will have lesser contributions.
-----If you intend to use combined images to create a master combine, then each of those sub-combines should be sums (preferably into 32-bit).
----Here is a good procedure:
***Process each group of exposures this way: by normalizing, doing data rejection, and finally doing a sum combine.
***Combine the processed subexposure sums with a simple mean (if the groups are equal) or a sum combine. You don't want to do normalization or data rejection for this combine.

I hope this helps,

dan