ASM
Real Time Geodetics
Chinese, Japanese and Australian astronomers working in China have combined remotely controlled radio telescopes in their three countries to create a single telescope. This massive telescope is being used to observe black holes on the edge of the universe.
The news is interesting outside the astronomy community because geodesists are considering the use of so called electronic very long baseline interferometry (e-VLBI) as a way of tracking the movement of the base stations that make up the world's fundamental reference frame, the International Terrestrial Reference Frame.
All legitimate co-ordinate measures on the surface of the Earth, such as GPS, can be traced back to the ITRF.
The ITRF is defined in terms of the positions of its reference stations, which are themselves defined in relation to measurements to distant astronomical objects.
Historically, this measurement has been difficult to do. It has been achieved by specific measurement campaigns, which need to be re-done every decade or so as the stations move under the influence of plate tectonics. E-VLBI opens up the possibility that the positions of stations could be continuously monitored to within a few millimetres.
This would have major implications for improved understanding of Earth processes such as earthquakes, tidal movements and the movements of continents.
One major issue is the amount of data that needs to pass between the telescopes.
The demonstration was made on 17 July at Shanghai Observatory during the 7th annual international meeting on e-VLBI.
Data was streamed at 512 Mbits/sec. It was gathered from the Shanghai Observatory, from the 34-metre telescope of the National Institute of Information and Communications Technology in Kashima, Japan, and from radio telescopes near Parkes, Coonabarabran and Narrabri in Australia. It was then sent to a supercomputer cluster at Swinburne University in Melbourne. It was processed there and then sent back to the observers in Shanghai.
