NIRISS Dark Template Parameters
JWST's NIRISS Dark Engineering template, available in the Astronomer’s Proposal Tool (APT), is used for calibration observations for the NIRISS instrument.
Introduction
These parameters are required to obtain Dark observations. Darks can be obtained with NIRISS as parallel observations (i.e. when another primary instrument is conducting science observations).
The NIRISS Dark 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 |
Special Requirements | specify special requirements | choose from list | if needed |
Template Specific Information | |||
select Subarray | choose from list | ||
Readout Pattern | specify readout pattern | NIS, NISRAPID | |
Number of Groups/Integration | specify number of groups per integration | number | |
Number of Integrations/Exposure | 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, and Special Requirements.
Subarray
SUBARRAY [SUBARRAY] = FULL, SUB64, SUB80, SUB128, SUB256,WFSS64R, WFSS64C, WFSS128R, WFSS128C, SUBSTRIP96, SUBSTRIP256
This parameter specifies the region of the SCA that is to be read out; see Table 1 for details.
Table 1. Subarrays for NIRISS Dark Image
Subarray | Size (cols x row) | Col corner | Row corner |
---|---|---|---|
FULL | 2048 x 2048 | 1 | 1 |
SUB64 | 64 x 64 | 1 | 1 |
SUB80 | 80 x 80 | 1969 | 925 |
SUB128 | 128 x 128 | 1 | 1 |
SUB256 | 256 x 256 | 1 | 1 |
WFSS64R | 2048 x 64 | 1 | 1 |
WFSS64C | 64 x 2048 | 1 | 1 |
WFSS128R | 2048 x 128 | 1 | 1 |
WFSS128C | 128 x 2048 | 1 | 1 |
SUBSTRIP96 | 96 x 2048 | 151 | 1 |
SUBSTRIP256 | 256 x 2048 | 1 | 1 |
SUBTAAMI | 64 x 64 | 1905 | 932 |
SUBTASOSS | 64 x 64 | 819 | 63 |
SUBAMPCAL | 1792 x 512 | 257 | 1537 |
Readout Pattern
READOUT PATTERN [READOUT PATTERN] = NIS, NISRAPID
This field specifies the readout pattern to be used to obtain the data. NIS is used for faint targets, while NISRAPID is used for bright targets or scenes with high backgrounds.
Number of Groups/Integration
NUMBER OF GROUPS/INTEGRATION [NGROUPS] specifies the number of groups in an integration. For readout pattern NIS, the range is 1-200, while for NISRAPID the range is 1-800.
Number of Integrations/Exposure
NUMBER OF INTEGRATIONS/EXPOSURE [NINTS] field specifies the number of times the integration is repeated. The range is 1-65535.