# Reference File¶

The msaflagopen step uses a MSAOPER reference file.

## MSAOPER Reference File¶

REFTYPE

MSAOPER

Data model

N/A

The MSAOPER reference file contains a list of failed MSA shutters and their failure state (stuck open, stuck closed, etc.)

### Reference Selection Keywords for MSAOPER¶

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

Instrument

Keywords

NIRSpec

INSTRUME, 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

### Type Specific Keywords for MSAOPER¶

In addition to the standard reference file keywords listed above, the following keywords are required in MSAOPER reference files, because they are used as CRDS selectors (see Reference Selection Keywords for MSAOPER):

Keyword

Data Model Name

EXP_TYPE

model.meta.exposure.type

### Reference File Format¶

The MSAOPER reference files are json format.

The fields are:

title

Short description of the reference file

reftype

Should be “MSAOPER”

pedigree

Should be one of “DUMMY”, “GROUND” or “INFLIGHT”

author

Creator of the file

instrument

JWST Instrument; should be “NIRSPEC”

exp_type

EXP_TYPEs this file should be used with; should be “NRS_IFU|NRS_MSASPEC”

telescope

Should be “JWST”

useafter

Exposure datetime after which this file is applicable

descrip

Description of reference file

msaoper
Q

Quadrant; should be an integer 1-4

x

x location of shutter (integer, 1-indexed)

y

y location of shutter (integer, 1-indexed)

state

state of shutter; should be “closed” or “open”

TA state

TA state of shutter; should be “closed” or “open”

Internal state

Internal state of shutter; should be “closed”, “normal” or “open”

Vignetted

Is the shutter vignetted? Should be “yes” or “no”

history

Description of the history relevant to this file; might point to documentation