TweakRegStep

class jwst.tweakreg.TweakRegStep(name=None, parent=None, config_file=None, _validate_kwds=True, **kws)

Bases: JwstStep

Perform image alignment based on catalogs of sources detected in input images.

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

class_alias
reference_file_types
spec

Methods Summary

process(input_data)

Perform image alignment based on catalogs of sources detected in input images.

Attributes Documentation

class_alias = 'tweakreg'

reference_file_types: list = []

spec = '\n        save_catalogs = boolean(default=False) # Write out catalogs?\n        use_custom_catalogs = boolean(default=False) # Use custom user-provided catalogs?\n        catalog_format = string(default=\'ecsv\') # Catalog output file format\n        catfile = string(default=\'\') # Name of the file with a list of custom user-provided catalogs\n        starfinder = option(\'dao\', \'iraf\', \'segmentation\', default=\'iraf\') # Star finder to use.\n\n        # general starfinder options\n        snr_threshold = float(default=10.0) # SNR threshold above the bkg for star finder\n        kernel_fwhm = float(default=2.5) # Gaussian kernel FWHM in pixels\n        bkg_boxsize = integer(default=400) # The background mesh box size in pixels.\n\n        # kwargs for DAOStarFinder and IRAFStarFinder, only used if starfinder is \'dao\' or \'iraf\'\n        minsep_fwhm = float(default=0.0) # Minimum separation between detected objects in FWHM\n        sigma_radius = float(default=1.5) # Truncation radius of the Gaussian kernel, units of sigma\n        sharplo = float(default=0.5) # The lower bound on sharpness for object detection.\n        sharphi = float(default=2.0) # The upper bound on sharpness for object detection.\n        roundlo = float(default=0.0) # The lower bound on roundness for object detection.\n        roundhi = float(default=0.2) # The upper bound on roundness for object detection.\n        brightest = integer(default=200) # Keep top ``brightest`` objects\n        peakmax = float(default=None) # Filter out objects with pixel values >= ``peakmax``\n\n        # kwargs for SourceCatalog and SourceFinder, only used if starfinder is \'segmentation\'\n        npixels = integer(default=10) # Minimum number of connected pixels\n        connectivity = option(4, 8, default=8) # The connectivity defining the neighborhood of a pixel\n        nlevels = integer(default=32) # Number of multi-thresholding levels for deblending\n        contrast = float(default=0.001) # Fraction of total source flux an object must have to be deblended\n        multithresh_mode = option(\'exponential\', \'linear\', \'sinh\', default=\'exponential\') # Multi-thresholding mode\n        localbkg_width = integer(default=0) # Width of rectangular annulus used to compute local background around each source\n        apermask_method = option(\'correct\', \'mask\', \'none\', default=\'correct\') # How to handle neighboring sources\n        kron_params = float_list(min=2, max=3, default=None) # Parameters defining Kron aperture\n        deblend = boolean(default=True) # deblend sources?\n\n        # align wcs options\n        enforce_user_order = boolean(default=False) # Align images in user specified order?\n        expand_refcat = boolean(default=False) # Expand reference catalog with new sources?\n        minobj = integer(default=15) # Minimum number of objects acceptable for matching\n        fitgeometry = option(\'shift\', \'rshift\', \'rscale\', \'general\', default=\'rshift\') # Fitting geometry\n        nclip = integer(min=0, default=3) # Number of clipping iterations in fit\n        sigma = float(min=0.0, default=3.0) # Clipping limit in sigma units\n\n        # xyxymatch options\n        searchrad = float(default=2.0) # The search radius in arcsec for a match\n        use2dhist = boolean(default=True) # Use 2d histogram to find initial offset?\n        separation = float(default=1.0) # Minimum object separation for xyxymatch in arcsec\n        tolerance = float(default=0.7) # Matching tolerance for xyxymatch in arcsec\n        xoffset = float(default=0.0), # Initial guess for X offset in arcsec\n        yoffset = float(default=0.0) # Initial guess for Y offset in arcsec\n\n        # Absolute catalog options\n        abs_refcat = string(default=\'\') # Catalog file name or one of: "\'GAIAREFCAT\'", "\'GAIADR3\'", "\'GAIADR2\'", or "\'GAIADR1\'", or None, or \'\'\n        save_abs_catalog = boolean(default=False) # Write out used absolute astrometric reference catalog as a separate product\n\n        # Absolute catalog align wcs options\n        abs_minobj = integer(default=15) # Minimum number of objects acceptable for matching when performing absolute astrometry\n        abs_fitgeometry = option(\'shift\', \'rshift\', \'rscale\', \'general\', default=\'rshift\')\n        abs_nclip = integer(min=0, default=3) # Number of clipping iterations in fit when performing absolute astrometry\n        abs_sigma = float(min=0.0, default=3.0) # Clipping limit in sigma units when performing absolute astrometry\n\n        # absolute catalog xyxymatch options\n        abs_searchrad = float(default=6.0) # The search radius in arcsec for a match when performing absolute astrometry\n        abs_use2dhist = boolean(default=True) # Use 2D histogram to find initial offset when performing absolute astrometry? We encourage setting this parameter to True. Otherwise, xoffset and yoffset will be set to zero.\n        abs_separation = float(default=1) # Minimum object separation in arcsec when performing absolute astrometry\n        abs_tolerance = float(default=0.7) # Matching tolerance for xyxymatch in arcsec when performing absolute astrometry\n\n        # SIP approximation options, should match assign_wcs\n        sip_approx = boolean(default=True) # enables SIP approximation for imaging modes.\n        sip_max_pix_error = float(default=0.01) # max err for SIP fit, forward.\n        sip_degree = integer(max=6, default=None) # degree for forward SIP fit, None to use best fit.\n        sip_max_inv_pix_error = float(default=0.01) # max err for SIP fit, inverse.\n        sip_inv_degree = integer(max=6, default=None) # degree for inverse SIP fit, None to use best fit.\n        sip_npoints = integer(default=12) #  number of points for SIP\n\n        # stpipe general options\n        output_use_model = boolean(default=True) # When saving use `DataModel.meta.filename`\n        in_memory = boolean(default=True) # If False, preserve memory using temporary files at expense of runtime\n    '

Methods Documentation

process(input_data)

Perform image alignment based on catalogs of sources detected in input images.

Parameters:

input_dataModelLibrary

A collection of data models. This can also be an ASN-type input to be read into a ModelLibrary.

Returns:

outputModelLibrary

The aligned input data models.