NASA's James Webb Space Telescope

New Version of General Target Visibility Tool Now Supports Moving Targets

News Feature March 9, 2018

NICMOS (HST) infrared image of Saturn. Credit: ESA/NASA.
NICMOS (HST) infrared image of Saturn. Credit: ESA/NASA.

The version of the JWST General Target Visibility Tool  (GTVT) that has been available for more than a year now has only supported targets with fixed coordinates.  This tool has now been enhanced so that users can enter moving target names and interface to JPL Horizons to ingest and use actual moving target ephemerides with the GTVT. This branch of the GTVT is referred to as the MTVT and  it is packaged with (and installed via) the GTVT as part of the GTVT installation process.  It is run via a separate command-line entry (“jwst_mtvt” instead of “jwst_gtvt”) that activates this branch of the tool.

If you previously installed the GTVT and do not care about moving targets, you do not need to reinstall the tool.  However, if you want to have access to the MTVT branch of the tool, you will need to re-install the GTVT (or install it, if you have not previously), following these steps:

  1. Follow the instructions provided in the GTVT help article in JDox; and
  2. Then follow the instructions in the MTVT help article to install the additional package callhorizons

You will then be ready to run the tool for moving targets.

If you have any questions, please reach out to the JWST Help Desk .