The largest and most visible scientific instruments on the PARI campus are the two 26 meter (85ft) radio telescopes.  Originally constructed by NASA for communications with manned spacecraft, the antennas could move at 3° per second across the sky. Weighing 750,000 pounds, with foundations extending 85 feet down into bedrock, the PARI 26 meter antennas were built to last. PARI has invested more than $1 million to enhance the telescopes and adapt them for the slow motion 15° per hour celestial tracking used in radio astronomy.

Student projects to improve the mechanical balance and precision of each antenna are underway with NC A&T State University in Greensboro. This involves fine tuning the placement of counterbalance weights on each antenna and measuring the surface accuracy of the parabolic portion and feed placement.

Currently, the East telescope carries a receiver at 327 MHz for studying pulsars.  The West radio telescope is used for studying the Milky Way Galaxy, supernova remnants and variable radio stars. It carries receivers for 1420 MHz and 4829 MHz.  Plans are underway to add additional frequencies to each antenna.

Through a collaborative effort with PARSEC, the radio telescopes will be combined into a two-element interferometer.  Funding has been received to purchase sensitive 2.2 GHz and 8.4 GHz receivers for each antenna.  The interferometer will be used for additional research into a phenomenon called IntraDay Variables (IDVs). IDVs are unseen clouds of matter or dark matter in space. PARI’s telescope array will watch for changes in brightness from distant normally constant radio sources as a way of mapping the size and location of these clouds of material.  The project will require several years to complete.

Additional upgrades are underway to add improved pointing accuracy, fiber optic cabling and feedbox temperature control to each antenna as part of grants from NASA and the National Science Foundation. The fiber optic cabling adds stability to receive signals, immunity to storm-induced lightning damage, enhanced reliability, and reduced maintenance costs. Another student project, temperature control of the feed electronics, improves sensitivity and accuracy of data taken by each antenna.

Students from NC A&T and UNC-Asheville are working on the design of a movable feed cartridge assembly to provide motorization of focus adjustments, which will allow each antenna to be readily reconfigured to serve a wide complement of frequencies as needed for new projects.