Software Tools To Help with Proposals

We provide you with a variety of tools to help you investigate options for viability and, ultimately, assist in the generation of a proposal for submission to the JWST Time Allocation process. We also offer a handy Pocket Guide that provides technical information about each instrument.



The Astronomer's Proposal Tool is used to write, validate, and submit proposals for both HST and JWST.


The Exposure Time Calculator performs signal-to-noise ratio calculations for all observing modes.


The Space Telescope Image and Spectroscopy Simulator (STIPS) simulates observations of large astronomical fields.


The Target Visibility Tools help you assess target visibilities before you enter information into APT.

More Tools


The PSF Simulation Tool simulates point spread functions for JWST instruments.

Simulated Data

Simulated data sets will help you become familiar with the new JWST instruments.


An overview of the JWST sensitivity and saturation limits is available.

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.