NIRSpec Focus Reference Template Parameters
JWST's NIRSpec Focus Reference template, available in the Astronomer’s Proposal Tool (APT), is used for calibration observations to perform Focus Reference observations.
Purple text indicates the parameter is Limited Access.
Boldface italics type indicates the name of an APT parameter or a value for a parameter.
Red text indicates restrictions on a parameter.
Black text indicates an important note.
Brown text indicates notes for the developers.
Green text indicates the name of the parameter used by Commanding.
Items in brackets - <value> - are required values.
Items in square brackets - [<value>] - are optional.
These parameters are required to reset the focus to one of two reference positions. This engineering operation is useful when the RMA location is unknown (for example, during commissioning) or lost (for example, if the ICSW is restarted, which resets the focus counter).
The following parameters define NIRSpec Focus Reference.
| Field | Details | Value | Notes |
|---|---|---|---|
| General Information | |||
| Observation Number | assign observation number | number | |
| Observation Label | provide observation label | text | optional |
| Observation Comments | provide observation comments | text | optional |
| Special Requirements | specify special requirements | choose from list | if needed |
| Template specific information | |||
| Direction | select focus direction | FORWARD, REVERSE | |
| Position | select focus position | MID_STROKE, LAUNCH | |
General information
The following parameters are generic to all templates, and are not discussed in this article: Observation Number, Observation Label, Observation Comments, and Special Requirements.
Direction
DIRECTION [DIRECTION] = FORWARD, REVERSE
This parameter specified the direction in which the focus should be moved.
Position
POSITION [POSITION] = MID_STROKE, LAUNCH
This parameter specifies the reference position that the focus should be moved to.