JWST ETC Calculations Page Overview

The JWST Exposure Time Calculator initializes a calculation once the user chooses an instrument and mode. Multiple calculations can be compared, copied, and modified in the ETC workbook. 

        Video Tutorial:  ETC General Overview

The Calculations* page in the JWST ETC is where a user specifies an instrument and mode, the background, instrument and detector configuration, and observing setup and extraction strategy for a given calculation. This is typically done after scene(s) and source(s) of interest have been defined on the Scene and Sources page, although a default scene containing a central point source is always available. The Calculations page offers users the ability to do a comparative analysis of multiple sources or locations in the scene to determine which calculation offers the best signal-to-noise ratio (SNR). 

List of articles

  1. JWST ETC Creating a New Calculation: Instructions for setting up, editing, and running calculations in the ETC.
  2. JWST ETC Backgrounds: Description of the available background options including example positions, dated backgrounds, and percentile options.
  3. JWST ETC Wavelength of Interest: Explanation of the Wavelength of Interest/Wavelength of Slice option and how to make best use of it in ETC calculations.
  4. JWST ETC Batch Expansions: Details on the various batch expansion options that can be used for quick exploration of SNR for different filters and detector parameters.
  5. JWST ETC Strategies: Landing page with links to individual articles on all of the available extraction strategies in the ETC.
  6. JWST ETC Target Acquisition: Landing page with links to individual articles detailing target acquisition (TA) calculations with all 4 science instruments.

* Bold italics style indicates words that are also parameters or buttons in software tools (like the APT and ETC). Similarly, a bold style represents menu items and panels.

Latest updates
    Updated for ETC v1.5. Video link added.

  • Updated for ETC v1.3
Originally published