Simulation Code

CGISim : Coronagraph Instrument Image Simulation Code

CGISim is a Python wrapper around the Python Roman PROPER model; it produces Coronagraph Instrument simulated images, optionally with EMCCD noise. An info session was held to explain the capabilities of CGISim+PROPER and to review some of the latest as-built optics measurements that are incorporated into the latest PROPER release. A recording is available, as are slides (Krist slides , Kuan slides).


FALCO + Coronagraph PROPER Model: HOWFSC Simulations

FALCO is a software package for coronagraphic wavefront sensing and control (WFSC), available in both Python and MATLAB. FALCO can utilize PROPER models as the truth models used to generate images. In this case, FALCO utilizes the PROPER model of the Roman Coronagraph Instrument included in the CGISim software package. Example scripts for running high-order WFSC (HOWFSC) with FALCO are provided for all supported and unsupported high-contrast mask configurations of the Roman Coronagraph Instrument. Instructions for how to run these FALCO+PROPER simulations are provided in the GitHub repositories' wiki pages for Python and MATLAB. More information about FALCO is also contained in a talk from the Coronagraph Information session in November 2021 as a pdf and an audio file. Note that FALCO does not currently wrap around CGISim itself, just the PROPER model. Also note that while the high-level HOWFSC algorithms are the same as for the instrument, FALCO is not the official HOWFSC software used by the Roman Coronagraph Instrument.


LOWFSSim: Coronagraph Low Order Wavefront Sensing and Control (LOWFS) Simulations

LOWFSSim is a package for modeling the Low Order Wavefront Sensing and Control (LOWFS) system on the Roman Coronagraph, available for Python 3.6 and newer. LOWFSSim utilizes prysm to perform integrated forward modeling of multi-plane diffraction, radiometric, thin film, and detector effects. It also includes the coronagraph's flight wavefront sensing algorithm for LOWFS, and the framework for the flight controllers. The public release of LOWFSSim includes API-level documentation as well as a user’s manual and several examples. LOWFSSim is able to model the system in closed loop at up to 2.2 kHz, faster than the 1 kHz operation of the hardware LOWFS system. More information about LOWFSSim is contained in a talk from the Coronagraph Information session in November 2021 (pdf and video recording).


WebbPSF: PSF Simulation Software for JWST

WebbPSF provides realistic point spread functions (PSFs) for use in data simulations, exposure time calculations, etc. WebbPSF is open source Python code and includes both a scripting interface and a GUI. Built at STScI, WebbPSF has been developed for JWST use but is being extended to include the Roman Space Telescope as well.


aXeSIM: A Slitless Spectroscopy Simulation Package

aXeSIM processes input lists of sources with various fluxes, positions, and SEDs to produce a simulated 2D slitless dispersed image. Sky background and random noise can be added to the output images. The simulation package uses the same components used by aXe (Kümmel et al. 2009) for the extraction of slitless spectra and thus aims at spectrophotometric integrity - useful for observation design but essential for the quantitative assessment of slitless data. Work is underway at IPAC and STScI to add more advanced instrumental and observational effects, such as intrapixel capacitance, charge diffusion, cosmic rays, and jitter and to include more flexibility, as required by the large field of view and complex focal plane of the Roman Space Telescope. aXeSIM comes as part of the STSDAS package for versions 3.10 and later.

GalSim: A Galaxy Image Simulation Tool

GalSim (Rowe et al. 2015) is a modular toolkit aimed at simulating WFI images - especially to simulate weak lensing images of galaxies. It uses realistic Hawaii-4RG detector effects (read noise, nonlinearity, interpixel capacitance, charge spreading among pixels, reciprocity failure), a Roman Space Telescope specific PSF, and throughput and filter curves from the current design reference mission.


IMCOM: Image Combination for Undersampled Images

IMCOM (Rowe, Hirata, & Rhodes 2011) is used for combining undersampled images and is often used for simulated images created by the GalSim tool.


GULLS Yield Microlensing Simulator

GULLS uses a modified version of the Besançon Galactic model (Kerins et al. 2009, Robin et al. 2003), with source star densities scaled to match red clump giant number counts from OGLE observations (Nataf et al. 2012) and event rates to match those measured from red clump giants by the EROS, MACHO, and OGLE collaborations (Popowski et al. 2005, Sumi et al. 2006, Hamadache et al. 2006). Although the simulations presented in Penny et al. (2013) were done specifically for the Euclid mission, the general information in that paper is also applicable to Roman Space Telescope observations.


MulensModel Microlensing Light Curve Generator and Fitter

MulensModel (Poleski & Yee 2018) calculates and fits gravitational microlensing light curves. The package provides a framework for calculating microlensing model magnification curves and goodness-of-fit statistics for microlensing events with single and binary lenses as well as a variety of higher-order effects: extended sources with limb-darkening, annual microlensing parallax, and satellite microlensing parallax. The software is easily adaptable to analyze the planned microlensing survey with the Roman Space Telescope.


SNANA: A Software Package for Supernova Analysis

SNANA (Kessler et al. 2009) is a public software package for supernova analysis. It contains a simulator, a light-curve fitter, and a cosmology fitter. The software is designed with the primary goal of using type Ia SNe as distance indicators for the determination of cosmological parameters, but it can also be used to study efficiencies for analyses of SN rates, estimate contamination from non-Ia SNe, and optimize future surveys.


STIPS: Space Telescope Image Product Simulator

STIPS is an STScI tool that allows the user to input or select a sky scene and create a simulated image as captured by one of three space-based observatories. Modules exist for HST/WFC3, JWST/NIRCam, JWST/MIRI, and Roman/WFI, although the latter is relatively new and is limited to a single H4RG array. The user can create on-the-fly sky scenes by choosing from a number of stellar and galaxy populations or by uploading his/her own images or catalogs. The user can then select various instrument modes (location on sky, exposure time, number of coadds, filters, etc.) for the observations.