massey-ccd-outline.md

note
The outline below is drawn from Massey 1997 guide to CCD Reductions

Why your data needs work and what to do about it (not likely to redo exact details)

Doing reduction

Outline of reduction steps

I imagine this will be very similar except maybe for some terminology

Examining frames to determine trim and bias

People should know they need to do this but they should also know to ask about the instrument they are using first.

Setting things up: setinstrument, parameters of ccdproc, and ``ccdlist`

No clue what this is...

Combining Bias Frames with zerocombine

Yeah, that is part of ccdproc and I don't think it needs that much emphasis?

First pass through ccdproc

Need to read this...

Constructing a bad pixel mask

Dealing with The Darks

In my experience, and with electrically cooled CCDs (let alone ones in a cryo tank) the dark current is small except for some hot pixels. See the notebook I wrote looking at darks and how linear pixels are.

Combining Flat-Field Exposures

Yikes....stay away from technique and hope we actually have some decent flats.

Normalizing spectroscopic flats using response

That is likely beyond me.

Flat-field division: ccdproc Pass 2

Getting the Flat-Fielding Really RIght

Combining the twilight/blank-sky flats

Creating the Illumination Correction

Finishing the flat-fielding

Fixing bad pixels

How many and what kind of calibratino frames do you need?

INs and Outs of Combining Frames

Note there is a nice paper about image combination also that talks about clipping before combining.

Summary of reduction steps

Spectroscopic example

Direct imaging example