calwebb_image2: Stage 2 Imaging Processing¶
- Class
- Alias
calwebb_image2
Stage 2 imaging processing applies additional instrumental corrections and
calibrations that result in a fully calibrated individual exposure. There are
two parameter references used to control this pipeline, depending on whether the
data are to be treated as Time Series Observation (TSO). The parameter reference
is provided by CRDS and the reftype pars-image2pipeline
. In general, for
non-TSO exposures, all applicable steps are applied to the data. For TSO
exposures, some steps are set to be skipped by default (see the list of steps in
the table below).
The list of steps applied by the Image2Pipeline
pipeline is shown in the
table below.
Step |
Non-TSO |
TSO |
---|---|---|
✓ |
||
✓ |
✓ |
|
✓ |
✓ |
|
✓ |
✓ |
|
✓ |
- 1
Resampling is only performed for exposure types “MIR_IMAGE”, “NRC_IMAGE”, and “NIS_IMAGE”.
Arguments¶
The calwebb_image2
pipeline has one optional argument:
--save_bsub boolean default=False
If set to True
, the results of
the background subtraction step will be saved to an intermediate file,
using a product type of “_bsub” or “_bsubints”, depending on whether the
data are 2D (averaged over integrations) or 3D (per-integration results).
Inputs¶
2D or 3D countrate data¶
- Data model
- File suffix
_rate or _rateints
The input to Image2Pipeline
is
a countrate exposure, in the form of either “_rate” or “_rateints”
data. A single input file can be processed or an ASN file listing
multiple inputs can be used, in which case the processing steps will be
applied to each input exposure, one at a time. If “_rateints” products are
used as input, each step applies its algorithm to each
integration in the exposure, where appropriate.
TSO and coronagraphic exposures are expected to use 3D data as input, to be processed on a per-integration basis.
Outputs¶
2D or 3D background-subtracted data¶
- Data model
- File suffix
_bsub or _bsubints
This is an intermediate product that is only created if “–save_bsub” is set
to True
and will contain the data as output from the
background step.
If the input is a “_rate” product, this will be a “_bsub” product, while
“_rateints” inputs will be saved as “_bsubints.”
2D or 3D calibrated data¶
- Data model
- File suffix
_cal or _calints
The output is a fully calibrated, but unrectified, exposure, using the product type suffix “_cal” or “_calints”, depending on the type of input, e.g. “jw80600012001_02101_00003_mirimage_cal.fits”.
2D resampled image¶
- Data model
- File suffix
_i2d
This is the output of the resample step and is only created for regular direct imaging observations (not for TSO or coronagraphy 3D data sets). The output file will use the “_i2d” product type suffix, e.g. “jw80600012001_02101_00003_mirimage_i2d.fits”. Note that this product is intended for quick-look use only and is not passed along as input to Stage 3 processing. Calibrated, but unrectified (_cal) products are used as input to Stage 3.
PARS-IMAGE2PIPELINE Parameter Reference File¶
- REFTYPE
PARS-IMAGE2PIPELINE
- Data model
N/A
Reference Selection Keywords¶
CRDS selects appropriate pars-image2pipeline references based on the following keywords.
Instrument |
Keywords |
---|---|
FGS |
EXP_TYPE, TSOVISIT, VISITYPE |
MIRI |
EXP_TYPE, TSOVISIT, VISITYPE |
NIRCAM |
EXP_TYPE, TSOVISIT, VISITYPE |
NIRISS |
EXP_TYPE, TSOVISIT, VISITYPE |
NIRSPEC |
EXP_TYPE, TSOVISIT, VISITYPE |
Standard Keywords¶
The following table lists the keywords that are required to be present in all reference files. The first column gives the FITS keyword names. The second column gives the jwst data model name for each keyword, which is useful when using data models in creating and populating a new reference file. The third column gives the equivalent meta tag in ASDF reference file headers, which is the same as the name within the data model meta tree (second column).
FITS Keyword |
Data Model Name |
ASDF meta tag |
---|---|---|
AUTHOR |
model.meta.author |
author |
DATAMODL |
model.meta.model_type |
model_type |
DATE |
model.meta.date |
date |
DESCRIP |
model.meta.description |
description |
FILENAME |
model.meta.filename |
N/A |
INSTRUME |
model.meta.instrument.name |
instrument: {name} |
PEDIGREE |
model.meta.pedigree |
pedigree |
REFTYPE |
model.meta.reftype |
reftype |
TELESCOP |
model.meta.telescope |
telescope |
USEAFTER |
model.meta.useafter |
useafter |
NOTE: More information on standard required keywords can be found here: Standard Required Keywords