Image data products

These data products are saved to disk as FITS files. PyEmir makes use of the FITS headers to record information about the data processing. This information may be recorded using other methods as well, such as the GTC Database or the standalone Pontifex database.

The following headers are included in all image data products and record information about the version of Numina and the name and version of the recipe used.

NUMXVER = '0.7.0   '           / Numina package version
NUMRNAM = 'DitheredImageRecipe' / Numina recipe name
NUMRVER = '0.1.0   '           / Numina recipe version
NUMTYP  = 'TARGET  '           / Data product type

HISTORY keywords may be used also, but the information in these keyword may not be easily indexed.

Master Bias frames

Bias frames are produced by the recipe BiasRecipe. Each bias frame is a multiextension FITS file with the following extensions.

Extension name	Type	Version	Contents
PRIMARY	Primary		The bias level
VARIANCE	Image	1	Variance of the bias level obtained from the input frames
VARIANCE	Image	2	Variance of the bias level measured on the result frame
MAP	Image		Number of pixels used to compute the bias level

Master bias frames are represented by MasterBias.

Master Dark frames

Master dark frames are produced by the recipe DarkRecipe. Each dark frame is a multiextension FITS file with the following extensions.

Extension name	Type	Version	Contents
PRIMARY	Primary		The dark level
VARIANCE	Image	1	Variance of the dark level obtained from the input frames
VARIANCE	Image	2	Variance of the dark level measured on the result frame
MAP	Image		Number of pixels used to compute the dark level

Master dark frames are represented by MasterDark.