The Palomar Testbed Interferometer (PTI)
Until 2008 the Palomar Testbed Interferometer (PTI), was operated by the Jet Propulsion Laboratory. It has since been decomissioned. It worked by collecting light with three small telescopes. The large distance between the small telescopes allowed for much higher resolution measurements to be made. The light was directed through pipes to the central beam combining building where it was analyzed. The separation among the three telescopes was 110 meters. During its lifetime the PTI was effectively the largest telescope on Palomar Mountain.
Flyer about the PTI (Adobe Acrobat)
Choose one of the telescopes listed on the right to see images and learn more about another of the Palomar Observatory's Telescopes.