INTEGRALNONLINEARITY Reference File

REFTYPE:

INTEGRALNONLINEARITY

Data model:

IntegralnonlinearityRefModel

The INTEGRALNONLINEARITY reference file contains per-channel lookup tables for correcting integral nonlinearity in the analog-to-digital converter.

Reference Selection Keywords for INTEGRALNONLINEARITY

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

Instrument	Keyword Attributes
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 Attributes for INTEGRALNONLINEARITY

In addition to the standard reference file attributes listed above, the following attributes are required in INTEGRALNONLINEARITY reference files, because they are used as CRDS selectors (see INTEGRALNONLINEARITY Reference File):

Attribute	Fully qualified path	Instruments
detector	model.meta.instrument.detector	WFI

Reference File Format

INTEGRALNONLINEARITY reference files are ASDF format. The file contains a lookup value array and correction tables for each of the 32 readout channels.

Data	Array Type	Dimensions	Data type
value	NDArray	65536	float64
inl_table.science_channel_NN.correction	NDArray	65536	float64

The value array contains the DN values (0-65535) used as lookup indices. Each science_channel_NN (where NN ranges from 01 to 32) contains a correction array with the INL correction offset for each DN value in that channel.