City scientists making waves in space

By Cai Wenjun  |   2008-6-18  |     NEWSPAPER EDITION

THE Shanghai Astronomical Observatory yesterday joined an international network of radio signal telescopes in a unique experiment using Very Long Baseline Interferometry (VLBI) which enables scientists to observe moving objects in space.

Local scientists joined researchers in Japan and Australia for yesterday's experiment which involved six telescopes from Shanghai, Japan and Australia and three computer centers from each country.

The VLBI technique can streamline research on space exploration, astrometry, spacecraft tracking and even earthquakes.

"Today's demonstration was a part of an international VLBI workshop held by the Shanghai Astronomical Observatory," said Shen Zhiqiang, a scientist with the Shanghai Astronomical Observatory and director of the local VLBI system. "The real-time VLBI is the world's most advanced technology and allows scientists to have immediate access to correlation results. Previously, scientists had to wait for days to get the results," Shen said.

The Shanghai VLBI system which was used to track Chang'e 1 orbiter last October and November, worked at a processing speed of 512 Mbps, a requirement for the international VLBI network.

This was the first time a domestic facility reached such a speed, experts said.

As well as imaging distant cosmic radio sources, spacecraft tracking, and for applications in astrometry, VLBI can also be used to study the earth's rotation, map movements of tectonic plates within millimeters, and perform other types of geodesy.

"Chinese scientists have introduced the system for the study of earthquake prediction but this is a long-term and complicated process," Shen said.