The Simulation Tools for Roman are still being developed as our understanding of the observatory and instrument capabilities are refined through integration and ground testing. This article is designed to provide some insight on future developments to assist users in the best course of action for their science goals.

Identified Improvements for Simulation Tools

The various elements of the Roman Space Telescope are still being tested and integrated. Some of the detailed understanding of how the Wide Field Instrument (WFI) will be operated (e.g., the reading patterns of the detectors), as well as its detailed throughput measurements and characterization of the detectors are still active areas of analysis. As a result, many of the simulation tools presented here will be updated during the preparation for launch as the observatory and instrument get better characterized. This page is meant to inform users of planned improvements or significant developments to existing Simulation Tools. 

Table of Development Planned for SOC Simulation Tools

Simulation Tool	Current Status	Future Status
WebbPSF	An approximation to the Roman primary mirror polishing errors is included based on those from HST.	Polishing errors will be updated to values measured from ground characterization of the actual Roman mirror.
STIPS	There are dependencies on both WebbPSF and Pandeia .	As WebbPSF and  Pandeia are improved, the results from STIPS will also improve.
Roman I-Sim	RDox documentation for Roman I-Sim was created and published in December 2024.	Development for this tool is ongoing and occurs in an open framework, but the tool is still under very active development. RomanISim will simulate Level 1 (L1) and 2 (L2) images with full instrumental effects.
Pandeia	Multi-accumulation tables are adopted from JWST.	Multi-accumulation tables will be updated to those used by WFI. While the tables have not been finalized, they will differ from those used in JWST because resultants will not always be evenly spaced.
	The current best throughput curves are implemented.	Throughput estimates will be updated based on ground characterization of the instrument.
	The WFI ETC Web Interface is available for easier access to ETC calculations.	Additional development of the web interface is ongoing.
Development Utilities:
pysiaf		No major changes are anticipated.
synphot	The current best throughput curves are implemented.	Throughput estimates will be updated based on ground testing of the instrument.
Jupyter Footprint Viewer	Jupyter Footprint Viewer for Roman RDox documentation was created and published in December 2024.	Please see the MAST GitHub Notebook Repository to learn more about what changes and development are taking place.

Software Versions Used in this Documentation

• This documentation is written for  WebbPSF version 2.0.
• This documentation is written for STIPS version 2.2.2 (released on December 16, 2024).
• This documentation is written for  Pandeia version 2024.12 (released on December 11, 2024).
• Roman I-Sim version 0.7.0 (released on December 6, 2024)

Caveats

Users should also refer to the Caveats sections for each tool to review both limitations and known issues with the SOC simulation tools. Some, but not all, of the known limitations for each simulation tool correspond to future areas of development. 

For additional questions not answered in this article, please contact the Roman Help Desk at STScI.