Slashdot Mirror
Incredible Images of the Sun
shelterit writes "A new swedish telescope facility in La Palma uses a new technology to remove the blurriness of the atmosphere to snap new and astonishingly sharp images of the sun. Want to have a closer look at the surface of it? Reminds me of paintings I did as a kid."
Still not as good as space based, but a damn sight cheaper! :)
\/eeoh
What in the world are they thinking putting them up as 3MB GIFs? I understand the need for super accuracy for some purposes, hence the need for lossless TIFFs, but there should be JPEGs for people who don't need perfect reproductions: The smooth gradients lend themselves to JPEG compression.
Well, I think the size of the mirror used might make it impractical for a soldier to carry one of these things around in a pair of goggles. ;) Also, it's a lot harder to apply adaptive optical techniques to lenses than to mirrors -- I work for a microscopy company (not as an optical engineer, granted, but that's what a lot of my coworkers do, and I hear them bitching) and we've had a hell of a time applying adaptive optical techniques to anything -- we have one product based on this idea that's only started shipping this year. I suspect the problems with lens-based telescopes and binoculars would be even worse, since the lenses in question are so much bigger.
That being said, I would be very surprised if there weren't military spy satellites, and perhaps reconnaisance planes, already using this.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
And the most fun to be had with an Adaptive Optics system is if it uses a laser generated guide star.
:)
:)
Then you can chuck a frisbee like object through the beam and watch it get zapped
Did I say this was seriously frowned on, I think I should
Adaptive Optics in a Nutshell:
1) You use a single point source as a reference.
2) You know the aberation caused by the atmosphere will spread the point image when you receive it.
3) You know that as your source is a point source, then the resultant spread in your image is entirely due to aberation, so use the image to calculate the Point Spread Function
4) Using the PSF apply a correction to the light path by altering something in the imaging system, usually a mirror.
5) Repeat several hundred times a second
Of course the great side effect is this also removes distortion caused by the imaging system itself, allowing you to use bigger mirrors with a lower tolerance than you otherwise might be able to do.
Originally point sources were strong and predictable stars in the field of view that you wanted - hence the term 'guide stars'
With a laser generated guide star you project a spot onto the upper surface of the atmosphere with a powerful laser of an appropriate frequency - close to your obsering frequency, but far enough out that you don't effect the observation. The subtlety here is to account for the fact that the point source will be spread twice, once on the way up and once on the way down.
Anyone working in AO I apologise to for the somewhat oversimplification - follow the links in the parent to better details if your interest is fired.
MtViewGuy says : While this new system works great for the visible spectrum of the Sun's output, you still want a space-based observatory to monitor the Sun's output in the other parts of the electromagnetic spectrum You will note that he ignores the critical first 3 words in that Nasa sentence.
teridon says "no, on the contrary, thats not true", and provides this quote from nasa.gov to support his refutation. "At optical wavelengths, these images are sharper than even current space-based solar observatories can produce."
and gets modded up to 5 ?
Hello.... READ. teridon basically confirmed what the other dude said - it works great, but only for for VISIBLE spectrum.
optical != electomagnetic.
/me shakes his head and mutters...