Intercontinental Remote Control: Observing with La Silla Telescopes from Garching
29 September 1987
ESO announces the establishment of the world's first system for interactive remote control of ground-based telescopes on another continent.
Since July 1st, 1987, European astronomers can perform astronomical observations with a telescope at the ESO La Silla observatory in Chile, while remaining at the ESO Headquarters in Garching bei München. This is made possible by a computer-to-computer connection via a satellite link between the ESO installations in Europe and South America.
From the “Remote Control Room" in Garching, the astronomer controls his telescope almost 12 000 km away, at the ESO La Silla observatory in the Atacama desert, about 600 km north of Santiago de Chile. The results of the observations, for instance direct images or spectra, are sent back via the same link in digital form. The astronomer can immediately inspect his data and decide about how to best continue his observations.
The system currently works on the 2.2 m telescope. It will be extended to the 1.4 m CAT in early October 1987 and later to other telescopes on La Silla. It is expected that more and more astronomers will prefer to stay in Europe and perform their observations at La Silla by remote control, avoiding the long and expensive trip to South America.
The remote control system includes transfer of TV-images of the focal field of the telescope, in order to center correctly the objects which shall be observed. There is also voice and telex connection between the observer in Europe and the night assistant in Chile, who is present in case of technical failure. The computer-to-computer data transfer takes place at 12000 baud. About 25 seconds are needed to transfer a TV picture. Spectra of astronomical objects are transmitted in less than 4 minutes and it takes 7 minutes to send a full CCD frame with about 164.000 image elements (320 x 512 pixels).
A major advantage is the possibility of very flexible scheduling of telescope time and short term reservation. Shorter observing programmes which do not justify the expense of travel to Chile, have now become possible. Recovery of lost observing time may also become feasible.
In the future, the leased line will also be used for other ESO communications during the daytime, ensuring even closer cooperation between the observatory and the Headquarters.
The operation of the present system is providing valuable experience for the remote control of the next large telescope on La Silla, the New Technology Telescope (NTT), which will become available towards the end of 1988. It is also expected that most observations with the ESO Very Large Telescope (VLT) will be performed by remote control from Europe. The VLT will consist of four individual telescopes with 8-metre mirrors, giving it the equivalent aperture of a 16-metre telescope. When ready in the late 1990's, it will be the world's largest optical telescope.
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