Other AMPATH News Items

Up (News home)

AMPATH Connects Gemini North and South

FIU Hosts AMPATH Applications Workshop

Brazil connects to SC2001

Arecibo Observatory on Abilene

High-Speed Links Connect 2 Telescopes 7,000 Miles Apart -- and the Astronomers Who Use Them
Chronicle of Higher Education, October 24, 2002

by Florence Olsen

article link: http://chronicle.com/free/2002/10/2002102401t.htm

When astronomers travel to an observatory, it's often "luck of the draw" whether they can accomplish what they signed up months earlier to try, says Peter Michaud, public information and outreach manager for the new Gemini Observatory. Atmospheric conditions at observatories are not always optimal, Mr. Michaud says, recalling the stories of astronomers who would come year after year to an observatory and "things wouldn't match up."

But Gemini's managers and science administrators now foresee a new era of scientific productivity resulting from advances in global networking. The most recent of these has linked the second of the Gemini Observatory's two 8-meter telescopes to the Internet2 backbone network, known as Abilene. The observatory, built over the last decade, has twin telescopes on different sides of the equator -- one in the Northern Hemisphere, on top of Mauna Kea, in Hawaii, and the other in the Southern Hemisphere, on Cerro Pachón, in the Chilean Andes.

The twin telescopes, separated by a distance of some 7,000 miles, were conceived from the outset to be connected by a high-speed network such as the Internet2 project's, so that the instruments could be used in tandem for observations that require a view of the entire sky. And they were designed so that astronomers would be able to use them from their campus offices, communicating online with technicians at the two sites, instead of having to travel to one site or the other.

"Those of us who like science think it's better to do more of it and to do it faster," says Thomas J. Greene, senior director of advanced-networking-infrastructure programs at the National Science Foundation. Both of those objectives are now possible because of the new link.

A $2.4-million NSF grant paid for the Internet2 connection to the Gemini South telescope, in Chile, and for the link's costs for the next three years. Two years ago, separate NSF grants of $600,000 and $340,000 paid for connecting Gemini North, in Hawaii, to the Internet2 backbone.

The Internet2 connection between the two telescopes was completed just in time, says James R. Kennedy, operations director for the $184-million observatory project. The Chilean telescope just became fully operational this year; the telescope in Hawaii has been in use for about a year and a half.

The Gemini Observatory is the result of a collaboration involving seven countries -- Argentina, Australia, Brazil, Britain, Canada, Chile, and the United States -- and more than 4,000 scientists from those countries. The observatory already receives six times as many proposals to use the telescopes as it can accommodate in a year, Mr. Michaud says.

With the Internet2 link complete, observatory managers say they will be able to allocate time on the telescopes more efficiently among astronomers -- and the astronomers can stay home and participate remotely. Typically, observatories allot astronomers fixed viewing times far in advance. But then poor weather conditions or equipment problems may prevent the scientists -- after traveling great distances -- from collecting data on the particular celestial objects that interest them.

The system enabled by Internet2, known as queue observing, ensures more productive scheduling of the telescopes, says Mr. Kennedy. Scientists whose proposals receive the highest ranking from independent reviewers are guaranteed time on one or both of the Gemini telescopes during optimal conditions for their proposed observation, no matter when those conditions occur.

When the queue-scheduling system is fully automated and debugged, astronomers will use a Web-based software tool to simulate the observation that they want to make, and the simulation will tell them whether the observation they are proposing is technically feasible.

Observation proposals, with information about the weather conditions required for the observation, will then be put into queues and linked to a meteorological modeling program that makes short-range forecasts of conditions at the telescopes' mountaintop locations.

The new system will mean that, instead of flying to Hawaii or Chile, scientists will receive a telephone call or an e-mail message 24 or 48 hours in advance, inviting them to participate in the observation remotely using high-speed videoconferencing over Internet2.

Rather than pacing back and forth in the control room at the telescope base station, the astronomer can be in his or her laboratory, interacting with the telescope operators, getting a quick look at the celestial images as they appear on the control-room monitors, and asking for on-the-spot adjustments. "These are all the things that you would do at the telescope if you were physically there," Mr. Kennedy says.

And astronomers with Internet2 access in their laboratories can use the network to retrieve observation data directly from the telescopes.

Not all scientists are thrilled about the new set-up, which Gemini officials have dubbed a "cyber observatory." Astronomers often like to be at an observatory "to get their hands on things," says Mr. Michaud. But with one night's use of the Gemini Observatory valued at $32,000, he says, it is critical to have the most efficient system for scheduling its use. Not all of the proposals that are accepted, for instance, require both telescopes to be used simultaneously. Research that requires only one telescope sometimes can be scheduled when bad weather is forecast for the other.

Few astronomers these days are actually permitted to have their hands directly on the controls of a major research telescope. The instruments have become so sophisticated that it takes professionally trained technicians months to become proficient at operating them.

And even the professional operators use computer networks to control the telescopes remotely. Conditions at 14,000 feet -- the height of Mauna Kea -- are not ideal for the clear-headed thinking that is necessary to control and trouble-shoot such a complex instrument, Mr. Kennedy says. "You have only 60 percent of normal oxygen levels in your blood. It's very difficult, especially when you're in the dark and it's cold, to make good, critical decisions at that elevation."

So operators control the Gemini telescopes from remote base stations below Cerro Pachón and Mauna Kea. Realistically speaking, says Mr. Michaud, "the days of the astronomer actually pushing the knobs and buttons on an observatory telescope are pretty much over."

Making the connection between Gemini's telescopes in Hawaii and Chile proved difficult and took more than two years' effort, says Julio Ibarra, director of research networking at Florida International University, in Miami. The university manages AmericasPath, or AmPath, an Internet exchange point for research and education networks in South and Central America, the Caribbean, and Mexico.

The fiber-optic connection linking the two telescopes is not a direct one across the Pacific Ocean. Instead, it takes a roundabout, but not noticeably slower, underwater route along the eastern coast of South America, to Miami. In Miami, the AmPath hub forwards data traffic from the Chilean telescope onto Internet2 backbone circuits located in Atlanta. The traffic crosses the United States over the Internet2 backbone to Seattle, and then moves across the Pacific on a fiber-optic cable to reach Hawaii. The total distance ends up at nearly 13,000 miles.