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.

(warning)Red text indicates restrictions on a parameter.

(red star) 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:

FieldDetailsValues Notes
General Information   
Observation Numberassign observation number

number


Observation Label provide observation labeltextoptional
Observation Commentsprovide observation commentstextoptional
Target Nameselect Target Namechoose from listfrom Target List

ETC Wkbk. Calc. ID

specify ETC Workbook Calculation IDnumberfor science exposures (optional) and target acquisition exposures
Special Requirementsspecify special requirementschoose from listif needed
Template Specific Information   
Target Acquisition Exposure



Acquisition Targetselect acquisition targetchoose from listif offset target
Acquisition Subarraydefault valueSUB32TATS
Acquisition Filterselect acquisition filterF335M, F405N+F444W
Acquisition Readout Patternselect acquisition readout patternchoose from list
Acquisition Number of Groups/Integrationselect number of groups per integrationchoose number from list
Acquisition Number of Integrations/Exposureselect number of integrations/exposure1only 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 

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, DEEP2, DEEP8

This field specifies the readout pattern to be used to obtain the acquisition data.

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

F070WF090WF115WF150WF150W2F200WF140MF182MF210MF187NF212N
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

F277WF322W2F356WF444WF250MF300MF335MF360MF410MF430MF460MF480M

CLEAR or

F162M of

F164N

CLEAR

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

Y

WLP8F323N

N

Y

N

N

N

N

N

N

N

N

N

N

WLP8F405N

N

N

N

Y

N

N

N

N

N

N

N

N

WLP8F466N

N

N

N

Y

N

N

N

N

N

N

N

N

WLP8F470N

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, DEEP2, DEEP8

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. (warning) 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 PatternMaximum Groups/Integration
RAPID

10

BRIGHT1

10

BRIGHT2

10

SHALLOW2

10

SHALLOW4

10

MEDIUM2

10

MEDIUM8

10

DEEP2

20

DEEP8

20

Number of Integrations/Exposure 

NUMBER OF INTEGRATIONS/EXPOSURE [NINTS] field specifies the number of times the integration is repeated. (warning)The range is 1 - 65535.

Change log

The initial version of this chapter was provided by Marsha Allen.

Change log


 

  1. PROPINSTJWST-91585 Updated Table 1 to allow F150W2 with CLEAR and WLP8.


Version 13 (May 11, 2022)

  1. PROPINSTJWST-91468 Added developer note about warning for visit splitting distance to Acquisition Target Name section.


Version 12 (May 28, 2021)

  1. PROPINSTJWST-89050 Added FULLP to Subarray section.
  2. Editorial change - Anchor links fixed in parameter table by removing pagename from link.

Version 10 (September 24, 2019)

  1. PROPINSTJWST-88134 - Added description of TA=NONE option to Acquisition Target Name section.


Version 9 (April 17, 2019)

  1. Editorial change (moved change log to main article).


Version 8 (December 21, 2018)

  1. PROPINSTJWST-91122 - Added developer note  in Acquisition Target section restricting acquisition target options for fixed vs. solar system observations.

Version 7 (December 27, 2017)

  1. PR 89483 - added restriction on Acq Target for SS observations
  2. PR 88411 - revised developer note to add TSO requirement


Version 6 (December 21, 2017)

  1. PR 89646 - updated the Acq Subarray name


Version 5 (September 5, 2017)

  1. PR 87895 - updated Exposure field labels to Groups/Integration and Integrations/Exposure


Version 4 (May 11, 2017)

  1. PR 87783 - revised TA NGroups


Version 3 (February 21, 2017)

  1. PR 87071 - removed mosaic option


Version 2 (November 14, 2016)

  1. PR 85330 - added target acquisition


Version 1 (May 11 , 2016)

This is the converted Word File from Chapter 22.