NIRISS Imaging Template Parameters
JWST's NIRISS imaging template, available in the Astronomer’s Proposal Tool (APT), has parameters for specifying and scheduling observations.
Introduction
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.
The NIRISS Imaging template is used for the direct imaging mode of NIRISS, and this article describes allowed values for all parameters. Advice on how to choose values which optimize your science can be found in the NIRISS Imaging APT Template article.
The NIRISS Imaging template consists of the following parameters:
| Field | Details | Values | Notes |
|---|---|---|---|
| General Information | |||
| Observation Number | assign observation number | number | |
| Observation Label | provide observation label | text | optional |
| Observation Comments | provide observation comments | text | optional |
| Target Name | select Target Name | choose from list | from Target List |
| specify ETC Workbook Calculation ID | number | for science exposures (optional) and target acquisition exposures | |
| Mosaic Properties | specify mosaic parameters | number | if needed |
| Special Requirements | specify special requirements | choose from list | if needed |
| Template Specific Information | |||
| Image Dithers | select Dither Name | choose from list | |
| Dither Pattern Size | select Dither Pattern Size | choose from list | |
| select Filter name | choose from list | ||
| select Readout Pattern | choose from list | ||
specify Number of Groups per integration | number | ||
specify Number of Integrations per exposure | number | ||
General Information
The following parameters are generic to all templates, and are not discussed in this article: Observation Number, Observation Label, Observations Comments, Target Name, ETC Wkbk. Calc. ID, Mosaic Properties, and Special Requirements.
Dither
The following parameters define the dithers for NIRISS Wide Field Slitless Spectroscopy.
Note to developers: Dithers are specified in the PRD table NirissWfssSecondary, EXCEPT the 3-DIRECT-* patterns are not included.
Image Dithers
IMAGE DITHERS [DITHER PATTERN TYPE] = NONE, 2, 3, 4 (default), 6, 8, 12, 16
This field specifies the number of dither points (see NIRISS Imaging Dithers). Dither = NONE is strongly discouraged for NIRISS Imaging of science targets.
Dither Pattern Size
DITHER PATTERN SIZE [PATTERN SIZE] = SMALL, MEDIUM [default], LARGE
This field specifies the size or amplitude of the dither steps (see NIRISS Imaging Dithers).
Filter(s)
Exposures are grouped by filter. For each set of exposures, specify the FILTER, READOUT PATTERN, NUMBER OF GROUPS/INTEGRATION, and the NUMBER OF INTEGRATIONS/EXPOSURE
For more information on defining an exposure specification, see Filters in the NIRISS Imaging APT Template article .
Filter Name
FILTER [FILTER] = F090W, F115W, F140M, F150W, F158M, F200W, F277W, F356W, F380M, F430M, F444W, F480M
Select the name of each filter to be used to obtain the data. For the filter bandpasses, see NIRISS Filters.
Readout Pattern
READOUT PATTERN [READOUT PATTERN] = NIS, NISRAPID
This field specifies the readout pattern to be used to obtain the data.
Number of Groups/Integration
NUMBER OF GROUPS/INTEGRATION [NGROUPS] specifies the number of groups in an integration. If READOUT PATTERN = NIS, the range is 1-200, while for NISRAPID the range is 1-30.
Number of Integrations/Exposure
NUMBER OF INTEGRATIONS/EXPOSURE [NINTS] field specifies the number of times the integration is repeated. The range is 1-10.