FITS reduction learning path

Read, calibrate, combine, and inspect images using the established astroimred API.

Start with a single FITS image. Add calibration and combination once the image’s units, header, and mask are understood.

Choose your next task

Task	Guide	Expected result
Read an image and inspect its metadata	FITS quickstart	A CCDData image and a header summary
Apply supplied calibration frames	Bias, dark, and flat correction	A calibrated image with a checkable pixel value
Combine calibrated exposures	Image combination	One image from a stack of exposures
Work from a terminal	Command-line tools	Copied, combined, or arithmetically transformed FITS files
Measure a source	Aperture photometry	Background-subtracted flux and instrumental magnitude
Inspect coma structure	Comet enhancement	Five enhancements of a packaged FITS image

The Python tutorials use small synthetic inputs or the packaged CometCIEF sample. The command-line guide uses placeholder FITS paths that you replace with your own files. No tutorial needs a telescope archive or a network service.

Use the reference for individual operations

The existing documentation groups the package into FITS management, image operations, preprocessing, and cosmic-ray rejection. The website keeps those topics and generates their reference pages from the current source docstrings.

Existing topic	Website reference
FITS files and headers	Read images and build summaries
Image operations	Copy sections and image arithmetic
Preprocessing	Calibration pipeline
Cosmic-ray rejection	Cosmic-ray removal and bad-pixel detection

For instrument data, select calibration masters, masks, rejection parameters, and uncertainty treatment explicitly. The examples demonstrate API behavior; they do not choose an observing program’s calibration policy.