Additional Simulation Tools
This page contains information on additional tools and utilities that support or complement our main suite of tools for Roman.
Software Freeze: To ensure a stable user experience, most Roman tools will not be updated during the Call for Proposals period. Users will be notified if any urgent fixes are released.
Introduction
Several tools are available for users who wish to create their own simulations or visualization of Roman Wide Field Instrument (WFI) observations. Here, we present complementary tools that users may find useful, including high-level summaries, links to additional documentation, and guidance on the use of the tools in the context of the Roman WFI.
| Tool Name | GitHub Repository | Website | RDox Article Link | Purpose |
|---|---|---|---|---|
STIPS | STIPS on GitHub | STIPS readthedocs | STIPS for Roman | Simulations of realistic astronomical scenes for WFI similar to Level 2 (L2) data products, including estimates of post-pipeline error residuals. |
pysiaf | pySIAF on GitHub | pySIAF ReadTheDocs | PySIAF for Roman | Transformations between detector, science, ideal, telescope, and sky coordinate systems for both the WFI and Coronagraph Instrument. Figures in this article provide context for the coordinate systems. |
synphot | Synphot on GitHub | Synphot ReadTheDocs | Synphot for Roman | Synthetic observations and photometry in WFI bandpasses (both imaging and spectroscopic modes) of input source spectra. |
Jupyter Footprint Viewer | Jupyter Footprint Viewer on GitHub |  The Jupyter notebook on GitHub is the main website for the tool. | Jupyter Footprint Viewer for Roman | Uses pysiaf information to display an instrument footprint on the sky. Can additionally query an astronomical catalog with the instrument footprint. |
STIPS
The Space Telescope Imaging Product Simulator ( STIPS ), allows users to generate simulations of realistic astronomical scenes with the Roman Wide Field Instrument (WFI). STIPS creates simulated scenes and overlays calibration residuals to approximate a WFI Level 2 data product.
Please note that STIPS is no longer under active development and is currently in maintenance mode, with updates limited to critical bug fixes.
For more information and examples, visit the STIPS for Roman page for Roman-specific details and installation instructions, as well as the ReadTheDocs page page.
pySIAF
The Science Instrument Aperture File (SIAF) is an XML-formatted file that describes the various coordinate systems used in the planning of WFI observations and creation of WFI data products. The SIAF itself contains a great deal of information necessary to set up these transformations, and pysiaf (Sahlmann et al. 2019) provides the tools necessary to read the XML file and presents the transformations as Python-based functions and methods.
For more information and examples, see the PySIAF for Roman page for Roman-specific information and installation instructions, as well as the ReadTheDocs page.
Synphot
The synphot Python package (Lim et al. 2016) was developed for general-purpose synthetic observations and photometry of input source spectra, and is a direct replacement for Astrolib PySynphot. synphot convolves bandpass information from the WFI with input spectra to create synthetic observations, and then integrates over the bandpass to estimate the flux that would be measured by the WFI. Additional functions and methods are also available, including various metrics of the bandpasses themselves such as their pivot wavelength.
Note that additional support packages and reference data are necessary for synphot to have access to WFI bandpass information. These include STPSF OR stsynphot , as well as the Spectral Atlas Files for Synphot Software.
More information may be found on the Synphot for Roman page for Roman-specific information and installation instructions, as well as the ReadTheDocs page.
Bandpass information for the Coronograph Instrument is not included in synphot . Other tools may be available for the Coronograph Instrument, and users should consult the Roman at IPAC page for more information.
Jupyter Footprint Viewer for Roman
This Jupyter notebook takes instrument footprint information from pysiaf and provides the Python code needed to both overlay the instrument footprint on survey data and query astronomical catalogs within the footprint. The footprint viewer is flexible enough to use many different instrument footprints, but tips and instructions for use with the Roman WFI footprint are provided on the Jupyter Footprint Viewer for Roman page.
For additional questions not answered in this article, please contact the Roman Help Desk.
References
- Sahlmann, J., Osborne, S., Cox, C., Proffitt, C. R., Law, D., Perrin, M., and Boyer, M. 2019, pysiaf, https://zenodo.org/record/3516964
- Lim, P. L. et al. 2016, synphot User's Guide (Baltimore, MD: STScI), https://doi.org/10.5281/zenodo.3673988