Sharpest Images With "Lucky" Telescope 165
igny writes "Astronomers from the University of Cambridge and Caltech have developed a new camera that gives much more detailed pictures of stars and nebulae than even the Hubble Space Telescope, and does it from the ground. A new technique called 'Lucky imaging' has been used to diminish atmospheric noise in the visible range, creating the most detailed pictures of the sky in history."
If they can do this from earth... (Score:5, Interesting)
Spider-sense (Score:5, Interesting)
Re:But surely... (Score:2, Interesting)
Not convinced by TFA (Score:5, Interesting)
Let's see it beat Hubble at: (Score:3, Interesting)
http://hubblesite.org/ [hubblesite.org]
There's a number of excellent Hubble images of just about everything in our solar system to the most distant galaxies.
I would put my money on Hubble, for two reasons.
First, the averaging algorithm is not without its flaws. They make the assumption that by averaging out a bunch of images, you eliminate distortion. For this to work, you have to assume that the probability of a particular pixel being in the right spot is higher as the distortion would essentially be random, and that could theoretically not be the case. If the distortion is completely random, then, averaging a set of images would essentially lose the pixel that is being pushed around its "real" spot by the atmosphere, and you can actually see that, as the corrected images still look muddy compared to their HST or even adaptive optic counterparts.
Secondly, the atmosphere doesn't just distort light, it also filters it. You can use averaging to remove distortion "noise", but, there's really no way to ascertain what information was removed by the atmosphere.
The bottom line is, yes, you can get some pretty good results with averaging software, but, if you have money to spend, the best images are going to be space based, and its still going to cost a billion dollars. Given the promise the heavens hold for the advance of human understanding, let alone essentially infinite resources, one only hopes that policy makers will not be mislead by the outrageous claim that one can get the best images from the ground. You can't. HST should not be thought of as an aberration made obsolete by adaptative optics or the low budget averaging. Low budget averaging and adaptive optics really need to be thought of as getting by until we can put larger, and better visible wavelength telescopes into space.
Imagine what a space based Mt. Palomar sized mirror could do, if in space!
Re:Lucky Imaging (Score:5, Interesting)
the wikipedia entry on this subject http://en.wikipedia.org/wiki/Lucky_imaging [wikipedia.org] states that new procedures take, '... advantage of the fact that the atmosphere does not "blur" astronomical images, but generally produces multiple sharp copies of the image'.
Does the correction algorithm apply a single vector to each image (ie the entire frame is shifted in unity) to produce the composite, or is a vector field applied to every pixel point in the image to shift individually the pixels toward their correct centres? Also if it is pointwise what type of transform is being applied, affine , perspective etc.
No, and this is why. (Score:3, Interesting)
No, the images we get right now from space telescopes are the best we can get at any given epoch, and that's just the way it is.
i invented the lucky telescope concept in 1995. (Score:4, Interesting)
here is my original post on
the sci.image.processing newsgroup
my old email address is no longer active.
new one is geopiloot at mindspring.com 9 reduce the numbers of ooo's in pilot to one
it was ironic that many people jumped out to say it wouldn't work at the time.
it does work and it works well. In fact most of the additive image processing now done by amateur astronomers everywhere using pc's software is based on my invention which I did not patent.
George Watson
From: George Watson (71360.2455@CompuServe.com)
Subject: virtual variable geometry telescope
This is the only article in this thread
View: Original Format
Newsgroups: sci.image.processing
Date: 1995/12/11
Has anyone implemented a virtual variable geometry telescope using
only a CCD attached to a normal non variable telescope?
It would work like this:
Take extremely short duration images from the CCD at a frequency
faster than the frequency of atmospheric distortion (1/60 sec I have
read is the minimal needed timeslice for physically corecting
atmospheric distortion in real time so maybe an exposure of 1/120 sec
would be short enough).
Choose via computer a high contrast image as a reference image.
Continue to take rapid short duration images and keep only the high
contrast ones with that have minimal displacement/offset from the
reference image.
Sum each of those acceptable images to a storage that will become the
final image.
What you should end up with is a final image that has minimal
atmosperic based distortion because all the low contrast and non
matching images will have been discarded.
Obviously you build an image over a longer period of time than with
real time optical correction but at perhaps lower cost.
Anyone know whether this has been proposed/done or researched?
--
George Watson
The opinions expressed here are those of the fingers
of George Watson only; not those of George Watson himself.
Please reply via this newsgroup. No Email unless requested,
Thanks.
View this article only
Newsgroups: sci.space.policy
Date: 1995/12/30