Issue 2: Unstable systems, noise
Astronomical observations are different from those in other scientific fields in that scientists can't just bring the object of their research into the controlled environment of a laboratory for analysis. Instead, they must use telescopes to make remote observations, recording whatever images or signals they can get.
"Clouds in the atmosphere, signals from other stellar bodies, or even simply instabilities in the telescope's systems can all generate noise that interferes with observations," explains Wu. "The moon, for example, reflects solar energy as a strong microwave signal. When making observations, we have to steer clear of the moon to prevent its noise from corrupting our data."
In addition, AMiBA is a new telescope, and not all of the bugs have been worked out of its systems. These occasional glitches are a headache for the team's scientists. "But you can encounter noise from system instabilities on almost any telescope," says Umetsu Keiichi, an assistant research fellow at Academia Sinica's Institute for Astronomy and Astrophysics (ASIAA) and member of the AMiBA team. "When it occurs, you just have to be patient, track down the cause of the problem, and continue with your observations."
The SMA research center on Mauna Kea is very well equipped. It has devices that add oxygen and pressure to the indoor air, as well as a small kitchen for the scientists who are making longer-term observations. The dishes that make up the array and the magnificent mountain-top scenery can be seen through the window in the research area. Life here is a far cry from the spartan conditions at the AMiBA base station on Mauna Loa.