Two tools exist for creating simulated JWST data from user-defined astronomical scenes. For the near-infrared instruments, MIRAGE can create simulated exposures for NIRCam imaging and wide field slitless spectroscopy (WFSS), NIRISS imaging, WFSS, and aperture masking interferometery (AMI) modes, and FGS imaging. For the mid-infrared MIRI instrument, MIRISim (Klaassen et al. 2021) is capable of producing simulated imaging, low-resolution spectroscopy, and medium-resolution IFU spectroscopic data. There are detailed example instructions for both MIRAGE and MIRISim in the user guides for the software.

A set of example simulated data for all 4 JWST instruments is also available.

Note, however, that these simulated data tools represent pre-flight capability and have not been kept up to date with the latest version of the JWST instrument models, the science calibration pipeline, or the latest calibration reference files. As such, users planning new observations should use the JWST Exposure Time Calculator to more accurately predict instrument sensitivity.

References

Klaassen, P., et al. 2021, MNRAS, 500, 2813
MIRISIM: a simulator for the Mid-Infrared Instrument on JWST