Reference File¶
The dark
step uses a DARK reference file.
DARK Reference File¶
- REFTYPE:
DARK
- Data models:
DarkRefModel
The DARK reference file contains pixel-by-pixel and frame-by-frame dark current values for a given detector readout mode.
Reference Selection Keyword Attributes for DARK¶
CRDS selects appropriate DARK references based on the following keyword attributes. DARK is not applicable for instruments not in the table.
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 Keyword Attributes for DARK¶
In addition to the standard reference file keyword attributes listed above, the following keyword attributes are required in DARK reference files, because they are used as CRDS selectors (see Reference Selection Keyword Attributes for DARK):
Attribute |
Fully qualified path |
Instruments |
---|---|---|
detector |
model.meta.instrument.detector |
WFI |
Reference File Format¶
DARK reference files are ASDF format, with 3 data arrays.
The format and content of the file is as follows
(see DarkRefModel
):
Data |
Array Type |
Dimensions |
Data type |
---|---|---|---|
data |
NDArray |
4096 x 4096 x ngroups |
float32 |
err |
NDArray |
4096 x 4096 x ngroups |
float32 |
dq |
NDArray |
4096 x 4096 |
uint32 |
The ASDF file contains a single set of data, err, and dq arrays.