Target Visibility Tools

The JWST project is making available several tools to help in assessing target visibilities and sky background levels prior to entering information in APT:

  • The General Target Visibility Tool (GTVT) works for both fixed and moving targets and provides information for all JWST instruments.
  • The Coronagraphic Visibility Tool (CVT) provides additional information for detailed planning of MIRI and NIRCam coronagraphic observations.
  • The JWST Backgrounds Tool (JBT) displays the sky background as a function of time.

These tools provide broad overview information that is not easily derived from APT, complementing APT’s detailed schedulability analysis. 


Figure showing CVT user interface.
The figure shows the CVT user interface, with the control panel on the left, the overview visibility plot in the center, and a specific instrument field of view on the right. The visibility plot shows both the windows in time when JWST can view the target and the allowed range of position angles over which the target can be viewed. By entering companions in the control panel, the tool displays tracks in the right panel showing the companion visibility as a function of time with respect to the selected instrument’s field of view, including any obscurations.


Software and Documentation

The visibility tools are being distributed as part of STScI’s AstroConda python distribution package, and the background tool is available via pip. Specific details for downloading AstroConda and activating each tool within the AstroConda environment are provided in the linked support articles below:


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For technical assistance, please contact the JWST Help Desk.


The NASA James Webb Space Telescope, developed in partnership with ESA and CSA, is operated by AURA’s Space Telescope Science Institute.