Infrared Spatial Interferometer

 observatory, telescope

The Infrared Spatial Interferometer (ISI) is operated by the University of California at Berkeley and consists of three 65-inch telescopes mounted in semi-trailers.
The ISI telescopes operate at mid-infrared wavelengths and combine the starlight received in the individual telescopes spaced up to 85 meters, in order to synthesize high-resolution images of red-giant and Mira variable stars. High-precision measurements of positions of stars in the mid-infrared will be instrumental to establish more precise astronomical reference frames, for example for navigation and high-precision tracking of interplanetary spacecraft equipped with infrared lasers.
Astronomers on the ISI team also participated in observations of Jupiter during the Comet Shoemaker-Levy impact and obtained spectroscopic data on ammonia gas thrown up into the higher atmosphere of the giant planet as a consequence of the impact.
The ISI system has been in operation at Mount Wilson Observatory since January 1988.