calwebb_image3: Stage 3 Imaging Processing

Config

calwebb_image3.cfg

Class

Image3Pipeline

Stage 3 processing for direct-imaging observations is intended for combining the calibrated data from multiple exposures (e.g. a dither or mosaic pattern) into a single rectified (distortion corrected) product. Before being combined, the exposures receive additional corrections for the purpose of astrometric alignment, background matching, and outlier rejection. The steps applied by the calwebb_image3 pipeline are shown below. This pipeline is intended for non-TSO imaging only. TSO imaging data should be processed using the calwebb_tso3 pipeline.

calwebb_image3

tweakreg

skymatch

outlier_detection

resample

source_catalog

Arguments

The calwebb_image3 pipeline does not have any optional arguments.

Inputs

2D calibrated images

Data model

ImageModel

File suffix

_cal

The inputs to the calwebb_image3 pipeline are one or more calwebb_image2 calibrated (“_cal”) image products. In order to process and combine multiple images, an ASN file must be used as input, listing the exposures to be processed. It is also possible use a single “_cal” file as input to calwebb_image3, in which case only the resample and source_catalog steps will be applied.

Outputs

CR-flagged exposures

Data model

ImageModel

File suffix

_crf

If the outlier_detection step is applied, a new version of each input calibrated exposure is created, in which the DQ array has been updated to flag pixels detected as outliers. These files use the “_crf” (CR-Flagged) product type suffix and also includes the association candidate ID as a new field in the original product root name, e.g. “jw96090001001_03101_00001_nrca2_o001_crf.fits.”

Resampled and combined 2D image

Data model

DrizProductModel

File suffix

_i2d

A resampled 2D image product of type “_i2d” is created containing the combined, rectified association of exposures, which is the direct output of the resample step.

Source catalog

Data model

N/A

File suffix

_cat

The source catalog produced by the source_catalog step from the “_i2d” product is saved as an ASCII file in ecsv format, with a product type of “_cat.”