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:

namestr: 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.
parentStep: 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_filestr or pathlib.Path: The path to the config file that this step was initialized with. Use to determine relative path names of other config files.
_validate_kwdsbool: Validate given kws against specs/config.
**kwsdict: 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[, input_bkg_list])

Subtract designated background images from target exposures.

Attributes Documentation

bkg_suffix = 'combinedbackground'

class_alias = 'bkg_subtract'

reference_file_types: ClassVar = ['bkg', 'wavelengthrange']

spec

bkg_list = force_list(default=None)  # List of background files. Ignored for WFSS or if asn is provided
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
soss_source_percentile = float(default=35.0) # Threshold flux percentile to mask out source pixels
soss_bkg_percentile = float_list(min=2, max=2, default=None) # Background percentiles to use; default is [25.0, 50.0]
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, input_bkg_list=None)[source]

Subtract designated background images from target exposures.

Parameters:

step_inputstr, ImageModel or IFUImageModel: Input target data model to which background subtraction is applied or asn file
input_bkg_listlist, optional: File name list of background exposures.

Returns:

resultImageModel or IFUImageModel: The background-subtracted target data model