Introduction to the WFI

The Wide Field Instrument (WFI) Imaging Mode User Guide provides an overview of the WFI and its role in the Roman mission.

The Introduction to the WFI currently includes 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  



This diagram provides a schematic view of the light path for the telescope and the WFI. Light from astronomical images enters the Roman telescope, a 2.4-meter aperture, is focused by the main and secondary mirrors before being passed to through the to the WFI. A series of flat mirrors brings the light into the WFI. The light passes through including the Element Wheel Assembly (EWA), that hosts the filters and dispersive elements. The light is focused the onto the focal plane, which is populated with 18 infra-red sensitive detectors. The detectors convert the photons into electrical signals to produce high-resolution, 300-megapixel images.


light bulb 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 Array 

The WFI has 18 detectors that are held in the Focal Plane Array, which allows it to create 300-million-pixel images over a 0.28 square degree field of view. In this photograph from the Detector Characterization Laboratory (DCL) at GSFC, the Focal Plane Array is visible already integrated into the Focal Plane System that contains the control electronics. The Video Introducing the WFI in the Context of the Spacecraft below provides more context. (Image credit: NASA/Chris Gunn; Link to Original)


Video Introducing the 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




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Publication

Initial publication of the article.