2004 ASTRONOMY & ASTROPHYSICS - Indian Academy of Sciences

CHAPTER 5
• Participation in the next generation
international projects
The next generation radio telescopes will be so
large, and therefore so expensive, that they will
almost certainly be built by an international
collaboration. The planning for the large Low
Frequency Array (LOFAR) and the Square
Kilometre Array Interferometer (SKAI) bears
testimony to this.
The Indian radio astronomy community has
received considerable international recognition
for its past effort, culminating in the building of
the GMRT. In order to retain this position of
eminence, we must participate in the big
international projects. India is already
represented on the ISSC (International Square
Kilometre Array Steering Committee). A
conscious decision should soon be made
to identify areas where we could develop
the necessary expertise to be able to
contribute something concrete to such
projects, and thereby become partners.
An artist’s impression of a 500 metre aperture spherical
telescope (FAST) proposed to be built in southwest
China. This is being projected as a prototype for the
SKA by the Chinese Academy of Sciences.
The Large Adaptive Reflector ( LAR ) is the Canadian
concept for a large steerable telescope. It will
consist of a long focal length, large diameter
parabolic reflector, composed of actuated reflector
panels controlled by a computer. The second
component is a focal package at a height of 500
metres, on a large helium balloon platform.
The picture shows an artist’s impression of one SKA
station composed of 400 Luneburg Lens antennas,
each 5 metre in diameter. It will form many
simultaneous, widely spaced, beams on the sky.
More than 100 such stations will be required for the
SKA. This is one of the several concepts being
investigated by CSIRO, Australia.
One of the options for a SKA is to use phased arrays
with over 50 million receiving elements with a
mixed RF/digital adaptive beam former.
The Thousand Element Array ( THEA ) is one of the
demonstrator systems built by ASTRON in the
Netherlands. The image shows four THEA tiles, each
consisting of 64 wide-band antennas.
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