Wednesday, September 5, 2007

Lucky Camera > Faster, Sharper, Cheaper > Q'n'A with Craig Mackay

A wave of “Wows” crossed the web when the latest results from the Lucky Camera were released.
Why the surprise? The images that now amaze us have the highest resolution direct images EVER accomplished in the visible, beating twice in resolution those obtaining by the Hubble Space Telescope.

OK...I’m not saying everything...while the HST is posted above Earth’s atmosphere, the work done by the Lucky team was performed without leaving our planet’s ground at the Mount Palomar telescope!

Sounds to good to be true?
Just check this comparison...:

(image credit: Craig Mackay and the Lucky Imaging Team 2005,2006,2007)

Now you see you see sharper...

Impressed? I am. Sounds to me that the future is just bright (and sharp...) under Lucky’s eyes...
I’ve contacted Craig Mackay, astronomer at the University of Cambridge and the man leading the project, that kindly answered some spacEurope questions.


Faster, sharper, cheaper...Can this be Lucky's mantra?

This sound good!

By what I understood the sharpest images are obtained by selecting and merging the ones taken by the high-speed camera that are least affected by Earth's atmosphere.
For how long as the camera to shot to capture variations of this nature in such short intervals of time allowing such differences from one image to the other?

We typically run at frame rate is of 20-50 pictures per second and will run for as many as 100,000 images which takes about half an hour.

As Lucky Imaging is not a new idea, being the principles used by amateur astronomy community to achieve some good quality images, in what consists the major innovation achieved by your project?

The amateur astronomy work emphasises using conventional television cameras. This limits their work to pictures of all the brightest objects, particularly the moon and planets.
We have been using very low light level cameras but the important innovation is combining those and the lucky imaging technique with the use of an adaptive optics system.
This gets rid of the low order distortion (turbulence on the largest scales) leaving lucky imaging to concentrate on sorting out the smaller scales.

We are living a new golden age for astronomy, how do you classify your project's contribution under this context?

In a few years Hubble will stop working. Astronomers will mostly be back with the sort of resolution they had 25 years ago. We must provide instrumental capability to do what has been done on the Hubble and in fact to exceed that. Equalling Hubble resolution is quite interesting but getting more resolution than Hubble will be very exciting and that is what we have done. It is clear that this ought to work on even larger telescopes such as the 8.2 metre VLT telescopes in Chile or the 10 meter telescope on the top of Mauna Kea in Hawaii.

Of what nature can Lucky's relation with Hubble be? A complementary one or, on the contrary it will help, somehow, to the, so many times equationed, end the telescope?

There are still an awful lot of the space telescope can do which ground-based telescopes simply cannot. In particular it can observe in those parts of the spectrum that do not get through the earth's atmosphere such as the ultraviolet and infrared where the atmosphere is completely hopeless from Earth.

And expectations regarding the next generation of telescopes?

The bigger the telescope the more difficult this work all becomes and I still think it is possible so I think these techniques will be usable in the future on even bigger telescopes.

Are there future observing trips already planned and which are the objectives?

We have an observing trip to Chile in February 2008 we will try to do more conventional lucky imaging.
We may well go back to Palomar at the end of 2008 depending on what observing programmes we wish to carry out.

Thinking of Lucky imaging as a step on a walk towards perfection what doors did it open for the next one?
From here to where?
How far and sharp can we, on Earth's ground, aim to see?

I think we should be able to get diffraction limited imaging in the visible from the ground on telescopes that are very much bigger than those at present working.

Other fields where Lucky imaging might be useful?

We have done a lot of work on surveillance imaging where we are able to improve resolution very markedly. Ground-based surveillance is often limited by atmospheric turbulence. The details on the way that you process the images are somewhat different but nevertheless a lot can be done and great images can be produced.

Can it possibly lend a hand to exoplanetary search?

Not very sure about this .
The only thing is that any imaging technique will be improved by using the basic principle of taking images rapidly,
checking each one quality and throwing those ones away that are not very good. That has all the lucky imaging actually does but as a fundamental principle it should work in any imaging mode where turbulence or any other distortion of a variable nature limits performance.


For more information about the Lucky Camera project please visit the project’s extremely detailed website here.

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