NIRCam Time Series Imaging Template Parameters
JWST's NIRCam Time Series 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 NIRCam Time Series Imaging template is used for the time series imaging mode of NIRCam, and this article describes allowed values for all parameters. Advice on how to choose values which optimize your science can be found in the NIRCam Time-Series APT Template article.
The NIRCam Time Series 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 | |
| Special Requirements | specify special requirements | choose from list | if needed |
| Template Specific Information | |||
| Target Acquisition Exposure | |||
| Acquisition Target | select acquisition target | choose from list | if offset target |
| Acquisition Subarray | default value | SUB32TATS | |
| Acquisition Filter | select acquisition filter | F335M, F405N+F444W | |
| Acquisition Readout Pattern | select acquisition readout pattern | choose from list | |
| Acquisition Number of Groups/Integration | select number of groups per integration | choose number from list | |
| Acquisition Number of Integrations/Exposure | select number of integrations/exposure | 1 | only allowed value |
| Science Exposures | |||
| select module | B | ||
| select subarray | choose from list | ||
| specify number of exposures for each dither point | number | ||
| select filter/pupil names | choose from lists | ||
| select readout pattern | choose from list | ||
| specify number of groups per integration | number | ||
| specify number of integrations per exposure | number | ||
Note for developer: This template cannot be used in parallel and cannot have parallels attached to it; the NO PARALLEL special requirement should be added. The TIME SERIES OBSERVATION special requirement should also be added. Note for developer: This template cannot be used with a mosaic.
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, and Special Requirement.
Target Acquisition
The following parameters are used to define NIRCam Target Acquisition observations.
Acquisition Target Name
The default for this parameter is "Same Target as Observation." If an offset star is to be used for the target acquisition observation, select the TARGET NAME [TACQ TARGET] from the list of fixed targets previously entered. When the science target is a Solar System target, the acquisition target MUST be the science target. Or, if no target acquisition is needed, select ACQUISITION TARGET to be NONE.
Note for developer: If the acquisition target is different from the science target, APT should provide a warning if the distance between the ACQ and Science targets is greater than the Visit splitting distance found in the PRD. Also, if there are multiple pointings within a visit, then the rules have to apply to the greatest separation between acq target and pointing within the visit.
Acquisition Subarray
The acquisition SUBARRAY is SUB32TATS.
Acquisition Filter
TARGET ACQUISITION FILTER [TACQ FILTER] = F335M, F405N+F444W
This parameter specifies the TARGET ACQUISITION FILTER to be used for the target acquisition.
Acquisition Readout Pattern
ACQUISITION READOUT PATTERN [TACQ PATTERN] = RAPID, BRIGHT1, BRIGHT2, SHALLOW2, SHALLOW4, MEDIUM2, MEDIUM8, MEDIUMDEEP2, MEDIUMDEEP8, DEEP2, DEEP8
This field specifies the readout pattern to be used to obtain the acquisition data. MEDIUMDEEP2 and MEDIUMDEEP8 are available for Cycle 4 and later.
Acquisition Number of Groups/Integration
NUMBER OF GROUPS/INTEGRATION [TACQ NGROUPS] = 3, 5, 9, 17, 33, 65
This parameter specifies the number of groups in an integration.
Acquisition Number of Integrations/Exposure
NUMBER OF INTEGRATIONS/EXPOSURE specifies the number of times the integration is repeated, and is always 1.
Science Exposures
Module
MODULE [MODULE] = B
There is only one choice for MODULE in this template. One long wavelength detector and one short wavelength detector in this module are used.
Subarray
SUBARRAY [SUBARRAY] = FULLP, SUB400P, SUB160P, SUB64P
This parameter specifies the region of the SCA detector that is to be read out. For more details about these subarrays, see Subarray in the NIRCam Time-Series APT Template article.
Number of Exposures/Dither
NUMBER OF EXPOSURES/DITHER [NEXP] field specifies the number of times the exposure is to be repeated.
Note for developer: APT should generate a warning if the visit duration is greater than 100 hours.
Exposure Specification
For each exposure, specify the FILTER-PUPIL pairs, READOUT PATTERN, NUMBER OF GROUPS/INTEGRATION, and NUMBER OF INTEGRATIONS/EXPOSURE. For the filter bandpasses, see NIRCam Filters, while for pupil information, see NIRCam Pupil and Filter Wheels. Note that only one exposure duration is allowed, and this will be used with both the long- and short-wavelength cameras. For more information on defining an exposure specification, see Exposure Time in the NIRCam Time-Series APT Template article.
Filter and Pupil Names
For each camera, select a FILTER [FILTLONG, FILTSHORT] - PUPIL [PUPILLONG, PUPILSHORT] pair from Table 1 and Table 2 of allowed configurations below.
Table 1. Supported Short Wavelength Optical Configurations
Filter Pupil | F070W | F090W | F115W | F150W | F150W2 | F200W | F140M | F182M | F210M | F187N | F212N |
|---|---|---|---|---|---|---|---|---|---|---|---|
| CLEAR | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
| F162M | N | N | N | N | Y | N | N | N | N | N | N |
| F164N | N | N | N | N | Y | N | N | N | N | N | N |
| WLP8 | N | N | N | Y | Y | Y | Y | Y | Y | Y | Y |
Table 2. Supported Long Wavelength Optical Configurations
| SW Pupil | Filter Pupil | F277W | F322W2 | F356W | F444W | F250M | F300M | F335M | F360M | F410M | F430M | F460M | F480M |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
CLEAR or F162M of F164N | CLEAR | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
| WLP8 | F323N | N | Y | N | N | N | N | N | N | N | N | N | N |
| WLP8 | F405N | N | N | N | Y | N | N | N | N | N | N | N | N |
| WLP8 | F466N | N | N | N | Y | N | N | N | N | N | N | N | N |
| WLP8 | F470N | N | N | N | Y | N | N | N | N | N | N | N | N |
Note to developer: The proposer to select the SW configuration first (with LW initially grayed out), then present only the allowed LW configurations.
Readout Pattern
READOUT PATTERN [READOUT PATTERN] = RAPID, BRIGHT1, BRIGHT2, SHALLOW2, SHALLOW4, MEDIUM2, MEDIUM8, MEDIUMDEEP2, MEDIUMDEEP8, DEEP2, DEEP8
This field specifies the readout pattern to be used to obtain the data. MEDIUMDEEP2 and MEDIUMDEEP8 are available for Cycle 4 and later.
Number of Groups/Integration
NUMBER OF GROUPS/INTEGRATION [NGROUPS] specifies the number of groups in an integration. See Table 3 for the maximum values as a function of READOUT PATTERN.
Table 3. Maximum Number of Groups/Integration for Time Series Imaging Observations
| Readout Pattern | Maximum Groups/Integration |
|---|---|
| RAPID | 10 |
| BRIGHT1 | 10 |
| BRIGHT2 | 10 |
| SHALLOW2 | 10 |
| SHALLOW4 | 10 |
| MEDIUM2 | 10 |
| MEDIUM8 | 10 |
| MEDIUMDEEP2 | 10 |
| MEDIUMDEEP8 | 10 |
| DEEP2 | 20 |
| DEEP8 | 20 |
Number of Integrations/Exposure
NUMBER OF INTEGRATIONS/EXPOSURE [NINTS] field specifies the number of times the integration is repeated. The range is 1 - 65535.