TV dish antennae as radio telescopes
- Indian researchers show that radio telescopes can easily be installed in any college campus
- Radio telescopes can be constructed with nothing more than an ordinary TV dish antennae
- Acquiring and analysing radio signals from space are more difficult than using an optical telescope
According to Pranshu Mondal, who led the team of researchers at the Indian Institute of Science Education and Research (IISER),Thiruvananthapuram, students and amateurs with no ready access to regular radio telescopes will greatly benefit from the instrument made from an ordinary television dish antenna.
Mandal, lead author of a paper on the instrument published last month (February) in Phys.org, says the improvised radio telescope is sensitive enough to pick up radio signals from Saturn and from the Milky Way galaxy. The paper says it will provide hands-on experience to students and amateurs.
Radio telescopes generally come in sizes ranging from 300 metres in width to smaller ones around 25 metres. Since radio waves have a longer wavelength than light waves in the electromagnetic spectrum, radio telescopes need large antennas to get data from space probes, satellites or other radio sources in space, Mondal says. “We took data for a longer span of time and averaged it and this enables detection of even small sources of radio waves from distant planets,” Mondal explains to SciDev.Net.
Joy Mitra, professor at the school of physics, IISER, tells SciDev.Net that the objective of the project is to demonstrate that to tune into radio frequencies from space even a simple device made of material bought off the market is good enough for students.
Mitra says observational astronomy using radio waves rarely finds place in curricula and few universities have large optical telescopes. In India, students normally acquire experience of radio astronomy through summer programmes run by research laboratories.
While it is possible for any college to set up a radio telescope, handling them requires a close understanding and analyses of radio signals received through them. “Radio telescopes do not readily produce pictures of celestial bodies like their optical counterparts. It requires sustained effort on the part of students — but it’s very doable.”
This piece was produced by SciDev.Net’s South Asia desk.