Running NICRED


Running NICRED can be as simple as executing the following command in a terminal: run_name input_data_directory

Where run_name is the name of the dataset (e.g. A1689_NIC3) and input_data_directory is the path to the uncalibrated data directory.

Getting NICMOS Data

The NICRED pipeline requires the full set of uncalibrated data products and best reference files for each observation in the input image set. These files can be readily obtained through the MAST HST archive. When requesting data from MAST you need to specify:

  • Science Files Requested: Uncalibrated
  • Reference Files: Best Reference Files

Optional Commands

For most image sets NICRED can be run in the default configuration with no additional interaction required. If the default settings are insufficient for processing a particular data set, there are a number of run-time options which may be applied to help improve the reductions:

  • Modules can be run manually step-by-step allowing for the inspection of the output at each step.
  • Modules can be skipped.
  • A pipeline run can be stopped, restarted or rerun at any stage of the reduction after the initial setup.
  • An external reference image can be used to improve the internal alignment of the reduced NICMOS frames.

Here’s a listing of the NICRED command line options:

Usage: run_name raw_in_dir

  --version             show program's version number and exit
  -h, --help            show this help message and exit
  --setup               run setup only
  --undopuft            run undopuft only
  --calped              run calped only
  --saaclean            run saaclean only
  --medsub              run medsub only
  --flatten             run flatten only
  --nonlincor           run nonlincor only
  --applymask           interrupt processing to manually run masking tools
  --align               run align only
  --weightmap           run weightmap only
  --mdrizzle            run mdrizzle only
  -a ALIGNREF, --alignref=ALIGNREF
                        external reference image used for alignment
  -n MODULE, --rerun=MODULE
                        rerun nicred from MODULE on
  -r, --restart         restart nicred
  -s SKIP, --skip=SKIP  Skip running module/s
  -t TARGNAME, --targname=TARGNAME
                        run nicred only on images with name TARGNAME on
  --pedsub              Use pedsub instead of pedsky
                        pixel scale (in arcsec/pixel) for final drizzled
                        images (default=0.1)
                        pixel fraction for final drizzled images (default=0.7)
  --drz_kernel=KERNEL   drizzel kernel for final drizzled images
  --noskysub            turn off multidrizzle sky subtraction
  --brightobj           take several actions to better cope with bright


Applying User Defined Masks

Run NICRED with the --applymask option. NICRED will stop processing after the nonlincor module and give instructions on how to run the masking tools on your data.


As we stated previously, NICRED was developed primarily for reducing imaging data of extragalactic sources. Here are some tips for reducing other types of data:

Add tips here

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