Radio astronomers nowadays have a number of excellent instruments to choose from for their research projects, such as the VLA, VLBA, Arecibo,etc. However, these instruments do not readily furnish the opportunity for student instruction in the technical aspects of radio astronomy that was available twenty five years ago or more. Such experience can in part be provided by small dedicated telescopes at universities. Such a radiotelescope has been installed at the University of Iowa. A commercial 4.5 meter satellite TV antenna has been modified to work as a radiotelescope. The radio telescope operates as a transit instrument, with computer control of elevation pointing. Working receivers exist at 5.0 and 1.4 GHz. Components exist for construction of receivers at 610 MHz and 15.0 GHz. Observations to date have been made of the Sun, Moon, Crab Nebula, and galactic HI. We have recently installed a mechanical switch in the 5 GHz front end, built switching electronics, and written a Labview virtual instrument to provide a Dicke radiometer. In the immediate future we plan to use this instrument to repeat the determination of the 5.0 GHz radio phase function of the Moon. Our presentation will include information on commercial sources of critical components for the system, such as low loss RF cables, low insertion loss mechanical switches, low noise amplifiers, etc.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1996