Introduction to WFI
This section of the Wide Field Instrument (WFI) Imaging Mode User Guide provides an overview of WFI and the Roman mission.
Section Table of Contents
This section of the WFI imaging mode user guide currently contains the following articles:
Under Construction
The WFI Imaging Mode User Guide is currently being written and developed. Please note that some topics are not yet available, and that some details will change during ground testing and commissioning.
Figure of the WFI relative to the Roman Telescope
Light enters through Roman's 2.4-meter aperture and is reflected and focused by the curved main mirror. This light is reflected and focused again by the secondary mirror. Additional optical elements tighten the light beam and remove stray light as it enters the Wide Field Instrument (WFI). Inside the WFI, the light passes through the Element Wheel Assembly. This wheel has a variety of filters that allow different wavelengths of light to pass through. Then the focused and filtered light reaches the focal plane, where it creates an image on the 18 detectors in the Focal Plane Array. These detectors use the photoelectric effect to convert photons into an electrical signal that is then then decoded into an image. WFI makes 300 megapixel images. The Video Introducing WFI in the Context of the Spacecraft below provides more context. (Credit: NASA's Goddard Space Flight Center. Link to Original)
View of the Roman Focal Plane Assembly
WFI has 18 detectors that are held in Focal Plane Array, which allows it to create 300-million-pixel images over a 0.28 sq degree field of view. In this photograph from the GSFC Detector Characterization Laboratory (DCL), the Focal Plane Array is visible already integrated into the Focal Plane System that contains the control electronics. The Video Introducing WFI in the Context of the Spacecraft below provides more context. (Image credit: NASA/Chris Gunn; Link to Original)
Video Introducing WFI in the Context of the Spacecraft
The capabilities of the WFI are fundamental to Roman's mission. The WFI features the same angular resolution as Hubble but with 200 times the field of view of WFC3/IR. This video provides a simplified version of how it works. (Credit: NASA's Goddard Space Flight Center. Link to Original, including a YouTube version with captions)
For additional questions not answered in this article, please contact the Roman Help Desk at STScI.
References
- Scientific Visualization Studio at NASA Goddard, "NASA's Nancy Grace Roman Space Telescope's Wide Field Instrument" Visualization ID: 13235, Created June 29, 2019 and Updated May 3, 2023
- Nancy Grace Roman Space Telescope at STScI