Technology -> The Instruments -> FGS

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The Fine Guidance Sensor is a very broadband guide camera that is incorporated into the cryogenic instrument payload in order to meet the image motion requirements of the JWST. This sensor is used for both "guide star" acquisition and fine pointing. The sensor operates over a wavelength range of 1 to 5 micrometers and has two HgCdTe detector arrays. Its field of view is sufficient to provide a 95% probability of acquiring a guide star for any valid pointing direction.

The Fine Guidance Sensor Tunable Filter Camera is a wide-field, narrow-band camera that provides imagery over a wavelength range of 1.6 to 4.9 micrometers, with a gap between 2.6 and 3.1 micrometers, via tunable Fabry-Perot etalons that are configured to illuminate the detector array with a single order of interference at a user-selected wavelength. The camera has a single HgCdTe detector array.

View our FGS image gallery.

Here is 15 second video clip of the Fine Guidance Sensor (FGS) model.   Formats: 5.7 MB .wmv

For more information, please visit the FGS website at the Space Telescope Science Institute http://www.stsci.edu/ngst/instruments/guider/