DARKDECAYSIGNAL reference file

REFTYPE:

DARKDECAYSIGNAL

Data model:

DarkdecaysignalRefModel

The DARKDECAYSIGNAL reference file contains amplitudes and time constants for the exponential model for dark decay for each of the 18 WFI detectors. Time zero is referenced to the middle of the first science read, so the typical amplitude of the signal in the first read should correspond to the value of the amplitude given in the reference file. Decay times are in seconds and amplitudes are in DN.

Reference Selection Keywords for DARKDECAYSIGNAL

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

Instrument	Keywords
WFI	instrument, 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

Reference File Format

DARKDECAYSIGNAL reference files are asdf files with a decay_table dictionary. This dictionary contains entries for each WFI detector, WFI01–WFI18. Each entry in the dictionary in turn contains a dictionary with two keywords, amplitude and time_constant, both floats. These are the amplitudes (in DN) and time constants (in seconds) of the exponentially decaying dark decay model that needs to be subtracted from uncalibrated Roman exposures.