FILTEROFFSET Reference File (MIRI only)

REFTYPE

FILTEROFFSET

Data model

FilteroffsetModel

Reference Selection Keywords for FILTEROFFSET

CRDS selects appropriate FILTEROFFSET references based on the following keywords. FILTEROFFSET is not applicable for instruments not in the table. All keywords used for file selection are required.

Instrument

Keywords

MIRI

INSTRUME, DETECTOR, EXP_TYPE, DATE-OBS, TIME-OBS

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

Reference File Format

The filteroffset reference file is an ASDF file that contains a list called filters. Every item in the list contains three fields - row_offset, column_offset and name - the name of the filter they are valid for. The offsets, in pixels, are applied in the image science frame.

filters
column_offset

Offset in x (in pix)

row_offset

Offset in y (in pix)

name

Filter name