GMRT

 GMRT-  Giant Meter wave Radio Telescope

     GMRT is a telescope that collects radio waves from the sky. As we already know, celestial objects can emit all types of rays, and only a little part of the light can pass through our atmosphere. Radio waves are one of them. Radio waves have wavelengths from several meters to some kilometers so they cannot be collected by the small size telescope. In other parts of the world, scientists had budget enough to build larger telescopes. but that was not the case in India.

    India had not enough money to build large telescopes which can withhold high-speed winds and corrosion. One of the astrophysicists in India named Prof. Govind Swarup had an idea. He with the help of other scientists and engineers in India build the telescope on a low budget, he made the main parabolic structure of the telescope with small wires with a 1 cm gap. so that it can hold in high-speed wind and we do not need stronger buildings. As the wavelength of the radio wave is high, the net-like structure of the telescope won't affect the ability of the telescope. GMRT became Asia's largest radio telescope.

Towers of GMRT

    GMRT has 30 dishes shown in the above picture spread over 100 acres of area.  Each dish in this array is a three-story building high. This array of telescopes is connected by optical fiber. Collected information is converted into an electronic signal like voltage and processed on the computer and then we can see an artistic image of the space as we cannot see radio waves directly.

Radio Galaxy was observed through the GMRT. 

     

      These images are artistic images, which means computerized images. There are some galaxies and celestial objects which emit only radio waves. Radio waves are emitted by ionized particles and clouds of dust in space. GMRT is capable of locating Pulsars accurately. 

    GMRT uses the technique of interferometry to make up the images of the space. The photons or a wave incident on the parabolic shape, gates reflected and collected by feed. Focused radiation on the feed antenna converts it into electrical voltage. it is amplified and processed on the computer. The radiation received by the antenna is not totally coming from the celestial sky. Some of the radiation is from objects around, such as television signals, FM signals, and also mainly mobile phone signals. This extra radiation is called noise and needs to be removed before processing the image. Increment in noise is a very big challenge in front of GMRT.

Basics of working of the radio telescope

 

       GMRT is a successful organization in radio astronomy. It also works in collaboration with the European VLBI network (EVN). It is a network of radio telescopes located primarily in Europe and Asia with additional Antennas and South Africa and Puerto Rico, which performs very high angular resolution observation of cosmic radio sources. For more information about the topic, visit my new blog on Radio Astronomy.