Reference Files

The saturation step uses a SATURATION reference file.

SATURATION Reference File

REFTYPE:

SATURATION

Data model:

SaturationRefModel

The SATURATION reference file contains pixel-by-pixel saturation threshold values.

Reference Selection Keywords for SATURATION

CRDS selects appropriate SATURATION references based on the following metadata attributes. All attributes used for file selection are required.

Instrument	Keywords
WFI	instrument, detector, date, time

Standard ASDF metadata

The following table lists the attributes that are required to be present in all reference files. The first column shows the attribute in the ASDF reference file headers, which is the same as the name within the data model meta tree (second column). The second column gives the roman data model name for each attribute, which is useful when using data models in creating and populating a new reference file.

Attribute	Fully Qualified Path
author	model.meta.author
model_type	model.meta.model_type
date	model.meta.date
description	model.meta.description
instrument	model.meta.instrument.name
reftype	model.meta.reftype
telescope	model.meta.telescope
useafter	model.meta.useafter

NOTE: More information on standard required attributes can be found here: Standard ASDF metadata

Type Specific Keywords for SATURATION

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

Keyword	Data Model Name	Instrument
detector	model.meta.instrument.detector	WFI

Reference File Format

SATURATION reference files are ASDF format, with two data objects. The format and content of the file is as follows:

Data	Object Type	Dimensions	Data type
data	NDArray	4096 x 4096	float32
dq	NDArray	4096 x 4096	uint32

The values in the data array give the saturation threshold in units of DN for each pixel.

The ASDF file contains two data arrays.