BackgroundStep

class jwst.background.BackgroundStep(name=None, parent=None, config_file=None, _validate_kwds=True, **kws)[source]

Bases: JwstStep

Subtract background exposures from target exposures.

Create a Step instance.

Parameters:

  • name (str, optional) – The name of the Step instance. Used in logging messages and in cache filenames. If not provided, one will be generated based on the class name.

  • parent (Step instance, optional) – The parent step of this step. Used to determine a fully-qualified name for this step, and to determine the mode in which to run this step.

  • config_file (str or pathlib.Path, optional) – The path to the config file that this step was initialized with. Use to determine relative path names of other config files.

  • **kws (dict) – Additional parameters to set. These will be set as member variables on the new Step instance.

Attributes Summary

bkg_suffix

class_alias

reference_file_types

spec

Methods Summary

process(step_input, bkg_list)

Subtract designated background images from target exposures.

Attributes Documentation

bkg_suffix = 'combinedbackground'
class_alias = 'background'
reference_file_types: ClassVar = ['wfssbkg', 'wavelengthrange']
spec
save_combined_background = boolean(default=False)  # Save combined background image
sigma = float(default=3.0)  # Clipping threshold
maxiters = integer(default=None)  # Number of clipping iterations
wfss_mmag_extract = float(default=None)  # WFSS minimum abmag to extract
wfss_maxiter = integer(default=5)  # WFSS iterative outlier rejection max iterations
wfss_rms_stop = float(default=0)  # WFSS iterative outlier rejection RMS improvement threshold (percent)
wfss_outlier_percent = float(default=1)  # WFSS outlier percentile to reject per iteration

Methods Documentation

process(step_input, bkg_list)[source]

Subtract designated background images from target exposures.

Parameters:

  • step_input (ImageModel or IFUImageModel) – Input target data model to which background subtraction is applied

  • bkg_list (list) – File name list of background exposures

Returns:

result – The background-subtracted target data model

Return type:

ImageModel or IFUImageModel