Processing HRS Data

hrsprocess includes steps for the basic CCD processing necessary for HRS data. The code provides a wrapper for tasks from ccdproc to provide specific reductions for HRS data. In addition, it provides several functions for creating calibration frames for the reduction of HRS data.

Note

hrsprcess expects files to follow the SALT naming conventions

Processing Data frames

Data frames can be process using the tasks blue_process and red_process. The user can select from several options included in these programs, but certain aspects are hard wired to provide convenient functions for data reductions. For example, to process blue data:

>>> from pyhrs.hrsprocess import blue_process
>>> ccd = blue_process('H201411170015.fits', masterbias=masterbias)

This will return an ccdproc.CCDData object that has had the overscan corrected, trimmed, gain corrected, had the master bias subtracted, and positioned such that the orders increase from the bottom to the top and the dispersion goes from the left to the right. Flatfielding and calibration from a spectrophotometric standard will only be applied in later steps.

Convenience functions for Processing Science Data:

• blue_process: process data from the HRS blue camera
• red_process: process data from the HRS red camera
• hrs_process: convenience function for processing HRS data

The functions all pass appropriate parameters to ccd_process. This tasks wraps functions from ccdproc for processing CCD images. ccd_process has a number of steps, which are all optional, that include overscan subtraction, trimming, creating error frames, masking, gain correction, and subtracting a master bias.

Processing Calibration Frames

Calibration frames can also be created using several convenience functions. For example, passing a list of filenames to create_masterbias will process the data and combine them to create the master bias frame.

>>> from pyhrs.hrsprocess import create_masterbias
>>> masterbias = create_masterbias(['H201411170015.fits', 'H201411170016.fits']

This will process each frame and return a masterbias ccdproc.CCDData object.

In addition, masterflats can be produced using:

>>> from pyhrs.hrsprocess import create_masterflat
>>> masterflat = create_masterflat(['H201411170020.fits', 'H201411170021.fits', 'H201411100022.fits']