Milestone-Proposal talk:The Giant Metrewave Radio Telescope (GMRT) – Pune, India

Revision as of 15:00, 2 August 2020 by Juan Carlos (talk | contribs)

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Review and support by Dr. Jacob Baars -- Juan Carlos (talk) 11:45, 31 July 2020 (UTC)

I am happy to fully support this initiative. I consider myself capable in this matter, having spent most of my career closely attached to radio telescope projects at a leading level. I was assistant project manager for the Westerbork Synthesis Radio Telescope in the Netherlands around 1970. Upon joining the Max-Planck-Institut für Radioastronomie in Bonn, Germany, I was Project Manager of the IRAM 30-m Millimeter Telescope in Spain (19180s) and the Heinrich Hertz Sub-millimeter Telescope in Arizona (1990s). After these projects I was Project Engineer for the Large Millimeter Telescope in Mexico during the design phase and I acted in several senior functions in the ALMA Project as ESO representative.

I have read the GMRT proposal that was attached to your message. It paints a good and complete picture of the project from the initial scientific justification and technical layout to the realization of the hardware in a remarkable indigenous concentration. I support it fully.

I would like to stress one aspect that for me is the most impressive achievement of the project. With the Ooty Telescope the Indian group of radio astronomers had already shown the capability to design and build instruments for a specific scientific purpose. When they considered how to realize a more powerful radio telescope, they recognized that concentrating on a low frequency instrument was not only astronomically highly relevant, because of the lack of such instruments world-wide, but also a viable avenue towards designing and building economically acceptable antenna structures. In short: they needed to build something big for a rock-bottom cost. The resulting design of the original SMART (Stretched Mesh Attached to Rope Trusses) telescope satisfied their goals: a high quality antenna, locally designed and constructed for an affordable low price.

With the GMRT India joined the "high technology" nations with an example of high performance technology, fully developed in the country, providing the science of astronomy with significant observational extension.

Jacob Baars, Member of the Historical Radio Astronomy working group of the IAU (Intl. Astronomical Union) Book: “Radio Telescope Reflectors - Historical Development of Design and Construction” , 2017

Review and support by Prof. Richard Schilizzi, Chair of the IAU working group on History of Radioastronomy -- Juan Carlos (talk) 14:59, 2 August 2020 (UTC)

Giant Metre-wave Radio Telescope – IEEE Milestone Proposal India was one of five countries around the world that pioneered radio telescopes at metre wavelengths in the years since WWII, the others being Australia, Italy, the USA and the USSR (Russia and Ukraine). The Netherlands has followed in the last two decades. In India, this pioneering work was driven by Professor Govind Swarup, one of the major figures in global radio astronomy. His first telescope was the Ooty Radio Telescope (ORT), a cylindrical paraboloid 530m long by 30 m wide (collecting area ~16,000 m2), operating at 327 MHz and completed in 1970. After years of successful work with ORT during which the radio astronomy community built up substantially in India, Swarup led an international African-Indian proposal in 1978 for a large array of parabolic cylinders with collecting area ten times that of the ORT (~200000 m2). This was to be located on the equator in Africa and called the Giant Equatorial Radio Telescope (GERT). However, by the end of 1983, it was clear that GERT would not be funded and Swarup turned his attention to a concept for a new national telescope in India called the GMRT. This was no longer based on cylinders but on the more flexible dishes that allow the telescope to be directed to any point in the sky.

Its design encompasses a number of innovations, one of which, the SMART antenna, was considered for the Square Kilometre Array (SKA) at an early stage. In the end, the SKA choice went to a much more expensive antenna design driven by a scientific requirement to observe at a much higher frequency limit than was possible with the SMART concept.

Since being declared an international facility in 2001, the GMRT, with its ~50,000 m2 collecting area, has been recognised as the most sensitive fully-steerable low frequency telescope in the world, supported by a world-class scientific and engineering staff. It is a multi-purpose Observatory attracting observing proposals from around the world on most of the important topics in astronomy and astrophysics. It showcases Indian achievements and innovation on the scientific and engineering fronts, and has been instrumental in educating many young students who have gone on to careers in astronomy at the most prestigious institutes and universities in the world. The experience accumulated over the years allowed the Observatory to take on leadership of the Telescope Manager design package for the SKA, a significant recognition in itself.

All this has been made possible by the GMRT. It is a significant technical achievement and worthy of an IEEE Milestone Award for its innovation and value for humanity.

Richard T. Schilizzi |Emeritus Professor of Astrophysics Department of Physics and Astronomy | School of Natural Sciences | The University of Manchester Chair of the IAU working group on History of Radioastronomy