NASA's James Webb Space Telescope

JWST ETC Version 1.2.2 Has Been Released

News Feature March 19, 2018

Screenshot showing the ETC screens depicting signal-to-noise version 1.2.2 enhancements.

The JWST Exposure Time Calculator (ETC) version 1.2.2 has been released. This is a patch release to the JWST ETC V1.2.

The patch release version 1.2.2 includes the following accuracy improvements and features:

  • Residual flat-field errors are reduced with multiple exposures treated as dithers.
  • Improved accuracy with redesigned and better-sampled PSFs for NIRCam and MIRI coronagraphy modes, and MIRI coronagraphic target acquisition.
  • Inclusion of pupil mask for NIRISS imaging in long-wavelength filters.
  • Enhanced coronagraphy strategy with four options available for PSF subtraction.
  • Saturation is reported separately for both nod positions for NIRSpec IFU and MIRI MRS.
  • Coronagraphy modes report saturation for the science scene and PSF subtraction source separately.
  • Performance and robustness improvements.

See the release notes for details and be sure to review the known issues for this release. 

The old workbooks from previous ETC versions will be locked to facilitate comparisons:

  • When you load them, they will open in read-only mode.  This ensures that your previous results are not overwritten and remain available to you for reference.
  • When you copy an out-of-date workbook and load the copy, all of its calculations will be automatically updated for you with the current version of the software.
  • For more information, see ETC Releases and Out-of-Date Workbooks.

If you have any questions about this release, please let us know via the JWST Help Desk.