MIRI Calibration Reference Files

This page provides information on the reference files used by the JWST pipeline to process JWST MIRI data. The information is organised by pipeline stages and lists all reference files needed for each step. Detailed information on the pipeline steps and files format is provided in the specified links.

On this page

The JWST pipeline provides science-ready calibrated data for all MIRI observing modes: imaging, coronagraphic imaging, medium resolution spectroscopy (via an integral field unit), and low resolution spectroscopy (slitted and slitless). The pipeline relies on the use of a set of reference files essential to ensure the correct and accurate process of the data.  This page gives details on the MIRI-specific reference files which are periodically updated. The following tables are organised according to the different pipeline stages, and provide information on all reference files used for the data reduction. In all cases xxxx replaces the version number of the file.



CALWEBB_DETECTOR1 reference files

This pipeline stage process the LVL1 up-the-ramp raw files and returns the level 2a files in units of (counts/sec). The pipeline steps flow for MIRI is different from that of the NIR instruments, and has been adjusted to better optimize the data treatment of the Si:As detectors in MIRI. The pipeline steps made use of the following reference files:


Table 1. MIRI reference files used by the JWST pipeline module calwebb_detector1.

Pipeline stepReference files usedUsability notes

Data Quality Initialization

 

Bad pixel mask file: jwst_miri_mask_xxxx.fits



Saturation check

Saturation file: jwst_miri_saturation_xxxx.fits



Intrapixel Capacitance Correction

IPC file: jwst_miri_ipc_xxxx.fits

This step is included in the pipeline, but disabled by default.

Pipeline step not applied to TSO data

Linearity Correction

Linearity file: jwst_miri_linearity_xxxx.fits



First Frame CorrectionPipeline step not currently used.Pipeline step not applied to TSO data
MIR RSCD

RSCD file: jwst_miri_rscd_xxxx.fits


Last Frame correction

Step does not use any reference file.Pipeline step not applied to in TSO data
Dark Subtraction

Dark file: jwst_miri_dark_xxxx.fits


Reference Pixels Correction

Pipeline step does not use any reference file. The correction uses reference pixels information stored in each exposure.
Persistence correction

This step uses three different files, that are currently being defined. This information will be updated soon.

The traps decay functions separated by family types

The trap density map.

The persistence saturation map.

Pipeline step not applied to TSO data
Jump Detection

Gain file: jwst_miri_gain_xxxx.fits

Readnoise file: jwst_miri_readnoise_xxxx.fits


Ramp Fitting

Gain file: jwst_miri_gain_xxxx.fits

Readnoise file: jwst_miri_readnoise_xxxx.fits




CALWEBB_Dark

This pipeline branch is intended for use with dark exposures. It applies all of the same detector-level correction steps as CALWEBB_Sloper and uses the same reference files, but stops just before the application of the dark subtraction step.



CALWEBB_IMAGE2 reference files

In this pipeline stage individual exposures from the imaging modes are processed from counts/sec to absolute flux units. During Cycle 1 no MIRI imager observations will be flagged as TSO. Hence, if obtained, they will follow the standard imaging pipeline processing. Details on the pipeline steps flow are given here.


Table 2. MIRI reference files used by the JWST pipeline module calwebb_image2.

Pipeline step

Reference files used

Usability notes

Assign WCS Information

Distortion file: jwst_miri_distortion_xxx.asdf

Filter offset: jwst_miri_filteroffset_xxxx.asdf


Background subtraction

Step does not use any reference file.

This pipeline step is not applied to Target Acquisition images. It subtracts a dedicated background image if requested by the oberver.

Flat Field Correction

Flat field file: jwst_miri_flat_xxxx.fits


Flux Calibration

Photom file: jwst_miri_photom_xxxx.fits

Area file: jwst_miri_area_xxxx.fits

Not applied to target acquisition images.

Rectify 2D Image





CALWEBB_SPEC2 reference files

This step process Individual exposures from the spectroscopic modes from counts/sec to absolute flux and wavelength units.  Nominally, this stage works on individual exposures. This page gives details on the pipeline flow.


Table 3. MIRI reference files used by the JWST pipeline module calwebb_spec2.

Pipeline stepReference files usedUsability notes
Assign WCS Information

Distortion file: jwst_miri_distortion_xxx.asdf

Spectroscopic WCS: jwst_miri_specwcs_xxxx.asdf

jwst_miri_specwcs_xxxx.fits

Regions: jwst_miri_regions_xxxx.asdf

V2V3: jwst_miri_v2v3_xxxx.asdf

Wavelength Range: jwst_miri_wavelengthrange_xxxx.asdf

jwst_miri_specwcs_xxxx.asdf and V2V3 needed for MRS

 jwst_miri_specwcs_xxxx.fits needed for LRS

Background subtraction

Step does not use any reference file.

Step only applied to the MIRI LRS
Flat Field CorrectionFlat field: jwst_miri_flat_xxxx.fits
Point vs Extended DecisionStep does not use any reference file.
Source Type DeterminationStep does not use any reference file.
Stray Light Correction

Stray light mask: jwst_miri_straymask_xxxx.fits

Only applied to MIRI MRS data
Fringe Correctionjwst_miri_fringe_xxxx.fitsOnly applied to MIRI MRS data
Pathloss correctionRef. file currently not in CRDSOnly applied to MIRI LRS data
Flux Calibration

Photom: jwst_miri_photom_xxxx.fits

RELSENS

RELSENS2D

RELSENS used for LRS data

RELSENS2D used for MRS data

Cube BuildingNo reference files are read by this step. All the reference file selection and reading is done in the assign_wcs step.
Extract 1D spectrumjwst_miri_extract1d_xxxx.json



CALWEBB_IMAGE3 reference files

Multiple exposures from the direct imaging modes (e.g., dither pattern or mosaic) are combined into a single rectified (distortion corrected) image. Details on the pipeline steps flow are given in this page.


Table 4. MIRI reference files used by the JWST pipeline module calwebb_image3.

Pipeline stepReference files usedUsability notes
Tweakreg Catalog

Step does not use any reference file.


TweakregStep does not use any reference file.
SkymatchStep does not use any reference file.
Outlier_detectionStep does not use any reference file.
ResampleStep does not use any reference file.
Source_catalogStep does not use any reference file.



CALWEBB_CORON3

This pipeline stage processes and combines multiple coronagraphic exposures.


Table 5. MIRI reference files used by the JWST pipeline module calwebb_coron3.

Pipeline stepReference files usedUsability notes
Assemble Ref PSFsStep does not use any reference file, but reference PSFs.
Align Ref PSFsUses PSF weighting Ref. File
Ref PSF SubtractionStep does not use any reference file.
Outlier DetectionStep does not use any reference file.
Create Exp Level ProductsStep does not use any reference file.
Image Combination/Resamplejwst_miri_drizpars_xxxx.fits



CALWEBB_SPEC3

Multiple individual exposures for the spectroscopic modes (i.e. dither patterns or mosaics) are combined into a single rectified cube and/or extracted spectrum.


Table 6. MIRI reference files used by the JWST pipeline module calwebb_spec3.

Pipeline stepReference files usedUsability notes
Background MatchingStep does not use any reference file.MRS only
Outlier DetectionStep does not use any reference file.
Create Exp Level ProductsStep does not use any reference file.
Cube CreationStep does not use any reference file.
Spectral Extraction 1Djwst_miri_extract1d_xxxx.json
Spectral Leak Sub.Need reference file (TBD)



CALWEBB_TSO3

This pipeline stage processes individual exposures taken in the Time Series Observation (TSO) modes.


Table 7. MIRI reference files used by the JWST pipeline module calwebb_tso3.

Pipeline stepReference files usedUsability notes
Outlier DetectionStep does not use any reference file.
Create Exp Level ProductsStep does not use any reference file.
Extract PhotometryRef. file TBDMIRI Imaging only.
Extract 1D Spectrumjwst_miri_extract1d_xxxx.jsonMIRI Spectroscopy only.
White-Light PhotometryStep does not use any reference file.MIRI Spectroscopy only.




Published

 

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    Tables 1, 2, 3, and 6