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Computerized imaging system producing sharper images than Hubble |
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Written by Derek Kessler on
Wednesday, 05 September 2007
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 Computer programmers and astronomers at the University of Cambridge in England have devised a method for taking pictures that are purportedly twice as clear as those taken by the venerable Hubble Space Telescope. Using a new system called "Lucky Imaging" they are taking normally noisy ground-based stellar observations and creating the sharpest images of the cosmos to date.
The changing temperatures and pressures of Earth's atmosphere not only causes stars to appear to 'twinkle,' but also thwarts the efforts of astronomers by blurring any images they try to take. Super sensitve cameras are able to beat the inevitable bluriness, but their extremely high speeds also produce noisy images that are filled with grain, making them practucally useless. For many years that problem has been solved by Hubble, but the orbiting telescope has cost more than a billion dollars in construction, launch, and maintenance.
Determined to create a ground-based solution that could take clear pictures and not cost several arms and legs, a Cambridge astronomer by the name of Craig Mackay turned to the power of numbers. Their new system takes pictures at a rate of 20 per second, analyzes and selects the best of the thousands of images taken, and digitally merges them together and eliminates furstrating noise.
The system produces images at or sharper than Hubble's at the cost of around $100,000 - less than 0.001% that of Hubble's ever-swelling price tag. The Lucky Imaging system was tested with the San Diego Palomar Observatory's 5.1-meter telescope. The observatory normally produces images about a tenth of the quality of Hubble's, but the new camera created images of the star cluster M13 that were twice as sharp instead.
While Lucky Imaging may produce clearer images of the cosmos, Hubble will still have its place, at least for now. The space telescope has the advantage of being able to take long exposure images, allowing it to peer deeper into space and time. Lucky will be most effective when coupled with large telescopes, such as Palomar, or the Keck Observatory atop Mauna Kea in Hawaii.
There's just one catch for Lucky Imaging, which is the same that thwarts the efforts of ground-based telescopes anyway: Clear skies and plenty of time are still needed to get clean exposures, especially if you want to beat Hubble.
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