Authors: Roman Project Science Team at NASA Goddard Space Flight Center
Released: 2026-04-06
Updated: n/a
Primary Reference(s): n/a
Please cite this Data Release Page URL when referring to these data products.
The vast majority of the photons in the point-spread function (PSF) generated by the Roman telescope and wide-field instrument are in a sharp spot dominated by diffraction, with minor alterations resulting from optical aberrations. This PSF is what is calculated by STPSF or similar tools.
A small fraction of the incoming photons, ranging from 0.1% at long wavelengths to about 0.7% at short wavelengths, are scattered far from the center of the PSF by micro-roughness on the mirror surfaces, by dust, and contaminants that accumulate over time. These scattering tails can extend hundreds of pixels from the center of the PSF.
Models of these scattering profiles have been calculated based on the measured micro-roughness of the optical surfaces and measured particle count and size distributions for the beginning of life (BOL) profiles. The End-of-life (EOL) distributions have an assumed increase in surface contamination.
These scattering tails are not included in STPSF output and will have to be included manually by the user. The files linked on this page are intended to give users a reasonable estimate of what to expect in flight. The profiles are monochromatic at filter bandpass center and are normalized to unit point source input intensity.
Brief descriptions of the released data and additional resources can be found below.