|
Small Radio Telescope - A Student's Dream by Ronald Clark After one has conceived and constructed a very low noise amplifier, what is more natural than connecting it to an antenna and pointing the antenna toward the sky. At that moment you become a Radio Astronomer. I have been making upper atmosphere wind measurements for over 25 years here at the University and one of my colleagues in this research has been Joe Salah, who happens to be Director of the MIT Haystack Observatory at Millstone Hill in Westford, MA. That facility has developed a small radio telescope (SRT) capable of continuum and spectral line observations in the L-band (1.42 GHz). This inexpensive radio astronomy kit was especially designed to benefit students of electrical engineering and physics. It provides everything needed to introduce students and amateur astronomers to the field of radio astronomy. A radio telescope is an excellent teaching tool as it involves the combined technologies of microwave engineering and digital computing. Its use involves astronomy, digital signal processing, software development, and analysis. The SRT is a standard seven-foot diameter satellite television dish mounted on top of a fully motorized Az-El mount. This unique mounting arrangement allows the observer to perform total power measurements and contour mapping. Software has been provided for controlling the antenna and selection of sources. Data reduction can be performed using existing radio astronomy software packages or left as an exercise for the student. Eberhard Moebius, Professor in the Space Science Center, and I have collaborated to obtain an SRT for the University. It now sits on the roof of Morse Hall and is coordinated by Prof. Moebius. Physics graduate and undergraduate students use the radio telescope to study astronomy, coordinate systems and source properties as part of their lab assignments. Engineering students can use the telescope to study low noise amplification, antenna properties, and digital signal processing. The system is capable of spectral frequency measurements utilizing very small bandwidths. In addition, the radio telescope can demonstrate to the public what radio astronomy is about. It is capable of showing a variety of objects, such as the sun, the Orion nebula, and the Milky Way. The SRT was the brainchild of Alan Rogers, a noted radio astronomer and physicist at Haystack. It was designed to be easy for students to use, to give useful results, and be very inexpensive to build. The SRT has been a 'hit' with the students. |
