JWST ETC Using the Sample Workbooks
Sample workbooks are designed with illustrative calculations to help users get started in using the JWST Exposure Time Calculator (ETC).
Video Tutorial: ETC Workbooks
Words in bold are GUI menus/
panels or data software packages;
bold italics are buttons in GUI
tools or package parameters.
A description of each column name is below:
#: Workbooks can be referenced by an ID number.
Name: The name of the available workbook.
Ver: Workbook was created in a previous version of the ETC. This column is blank for workbooks created in the current version of the ETC.
Load: Load and access sample workbook.
Description: Brief description of the calculations contained in the workbook.
Options: Users can create a new copy or remove the workbook from their list of available workbooks.
Sample workbooks are designed to help users become acclimated with the Exposure Time Calculator (ETC) and various instrument modes. This can include basic point source imaging for utilizing sensitivity calculations of each JWST instrument, imaging with multiple extended sources, coronagraphic imaging, slitted spectroscopy, and IFU calculations.
Example science program workbooks
These workbooks are associated with the example science programs, which present realistic science programs for users to explore the steps in creating a proposal from scratch. These include observations of stars, galaxies, and Solar System targets with the full range of observing modes. ID numbers in the titles of each workbook are provided for easy matching of JDOX articles, ETC workbooks, and APT files for each example science program.
From the Available Workbooks pane, click the SAMPLE WORKBOOKS or EXAMPLE SCIENCE PROGRAM WORKBOOKS button to obtain a list of pre-made workbooks. Once a workbook of interest is clicked, an independent copy is added to a user's list of available workbooks. To access the workbook, click Load. The user can modify these workbooks for their own ETC calculations. The sample workbooks that have been copied are independent copies, so modifying them does not affect the master workbook. Users can always go back to the landing page and get another copy of the sample workbook provided with the ETC. When a workbook is opened, it is on the Calculations tab by default. There are pre-defined scenes and sources already available, and they have been created to illustrate the features that are most relevant to the observing mode with the given instrument. Note that any given workbook (for example, with slitless spectroscopy calculations) contains calculations for different instruments that allow that specific observing mode. In the case of the sample workbooks, the Calculations tab has a Notes pane at the bottom explaining each calculation.
When you load the old workbooks, they will open in "Read-only" mode. This ensures that the results from the previous version are not overwritten and will be retained for reference.
To update your old workbooks and work with them in the current ETC:
- Identify the workbook you want to use from the list of available workbooks.
- Click Load to open the read-only version of the old workbook.
- Click Copy on the right-hand side of the row that contains the workbook. This creates an exact copy of the selected workbook and appears on the list of available workbooks.
- Click Load to open the copied workbook in a separate tab.
- All the calculations in the workbook will be automatically updated using the current version of the ETC software.
- Compare the new results with those of the previous ETC version in the other tab.
Pontoppidan, K. M., Pickering, T. E., Laidler, V. G. et al., 2016, Proc. SPIE 9910, Observatory Operations: Strategies, Processes, and Systems VI, 991016
Pandeia: a multi-mission exposure time calculator for JWST and WFIRST