Radio telescope to measure sun's atmosphere

CURRENT Radio Telescope to Measure Sun's A t m o s p h e r e . - - A new type of radio telescope will soon begin the task of exploring the sun's turbulent atmosphere. The Air Research and Development Command's Air Force Office of Scientific Research has financed the construction of this new apparatus, after conception of the idea by Stanford University. Called a microwave spectroheliograph, the device will carry on its explorations from an observation point on the Stanford University campus. It consists of 32 parabolic aluminum antennas, known as "dishes," which will be aligned in two rows to form a huge cross occupying a level, two-acre meadow. Under the direction of Professor Ronald N. Bracewell of Stanford's Radio Propagation Laboratory the device will pick-up solar microwave radiations in the 3000 megacycle region. As the dish antennas scan the sun's surface in the same way a television camera scans its subject, the photograph produced shows the "chromosphere" a hitherto mysterious billowing layer of incandescence, rising to heights of 6000 miles above the sun's surface. Although discovered many years ago at the time of solar eclipses, little is known about the chromosphere. The development of radio astronomy in the postwar era has renewed efforts to unveil its secrets. It is believed to have some connection with sunspots, which in turn are related to magnetic storms which interrupt radio communications. The 32 antennas will look straight 88

TOPICS at the sun, scanning its surface in unison, and following automatically as it crosses the sky. A photograph of the entire solar orb will be completed in about two hours. Clouds will not affect antenna efficiency. Dr. Bracewell has recently served as a research officer with the Commonwealth Scientific and Industrial Research Organization at Sydney, Australia, a world center of radio astronomy research. A primary accomplishment will be the scanning of solar regions as small as three-thousandths of one square degree, a definition finer than ever before achieved in radio astronomy or in radar. Stratospheric T V.--Television moved into the supersonic age with the recent announcement by Philco Corporation that it has developed an airborne T V system which may be used in jet aircraft reconnaissance by the U. S. Air Force. Developed at Philco's Government & Industrial Division for the Aerial Reconnaissance Laboratory at Wright Air Development Center, the new airborne T V system will provide ground control points with an active picture of troop movements or terrain. It now is possible to transmit a T V picture, not only from near ground level, but from the stratosphere, beyond reach of antiaircraft gun fire. The scope of such a reconnaissance system is almost unlimited. Unlike those systems which have been used commercially to relay T V signals from one ground point to another, via a slow-circling plane, the new airborne reconnaissance system is a complete, self-contained, broadcasting