14 DAY TRIAL // The Mileura Widefield Array - Low Frequency Demonstrator (LFD), which is being built in Australia by the United States and Australian Partners, will also allow scientists to better predict solar bursts of superheated gas that can play havoc with satellites, communication links and power grids.
"This is the most crucial measurement to be made in support of our National Space Weather Program, since it would provide advance notice about the space weather effects on Earth well ahead of the time of impact of the plasma burst," said Joseph Salah, director of the Haystack Observatory.
In support of the solar observations, the Air Force Office of Scientific Research also recently made a $0.3M award to MIT for array equipment.
"The design of the new telescope is tightly focused on frontier experiments in astrophysics and heliospheric science. We plan to harness the enormous computing power of modern digital electronic devices, turning thousands of small, simple, cheap antennas into one of the most potent and unique astronomical instruments in the world," said Colin J. Lonsdale, the project's leader at MIT's Haystack Observatory.
The LFD will be an array of 500 antenna "tiles" spread out over an area 1.5 kilometers, or almost a mile, in diameter. Each tile is about 6 meters square and consists of 16 simple and cheap dipole antennas, fixed on the ground and staring straight up.
Big conventional telescopes are characterized by huge concave disks that tip and tilt to focus on specific areas of the sky. Thanks to modern digital electronics, the LFD tiles can also be "steered" in any direction -- but no moving parts are required. Rather, the signals, or data, from each small antenna are brought together and analyzed by powerful computers. By combining the signals in different ways, the computers can effectively "point" the telescope in different directions.
"Modern digital signal processing, enabled by advances in technology, are transforming radio astronomy," said Lincoln J. Greenhill of the Harvard-Smithsonian Center for Astrophysics.
This concept has been tested at the proposed Radio Astronomy Park at Mileura in Western Australia with three prototype tiles "lovingly wired together by hand" by MIT and Australian graduate students and researchers, Hewitt said. "The tiles performed very nicely. We were quite pleased with them."
The LFD telescope will operate at the same radio wavelengths where FM radio and TV broadcasts are normally found, so scientists plan to install the telescope in the remote area of Mileura where the signals of civilization cannot swamp the radio whispers from the deep universe. The planned site at Mileura is both exceptionally "radio quiet" and also highly accessible.
"Radio astronomical telescopes operating at low frequency provide an opportunity to witness the formation of the first stars, galaxies and clusters of galaxies, and to test our theories of the origin of structure," said Jacqueline Hewitt, director of the MIT Kavli Institute and a professor of physics. She added that "direct observation of this early epoch of structure formation is arguably one of the most important measurements in astrophysical cosmology still to be made."
